1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * drivers/i2c/busses/i2c-tegra.c
4 *
5 * Copyright (C) 2010 Google, Inc.
6 * Author: Colin Cross <ccross@android.com>
7 */
8
9 #include <linux/acpi.h>
10 #include <linux/bitfield.h>
11 #include <linux/clk.h>
12 #include <linux/delay.h>
13 #include <linux/dmaengine.h>
14 #include <linux/dma-mapping.h>
15 #include <linux/err.h>
16 #include <linux/i2c.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/iopoll.h>
21 #include <linux/irq.h>
22 #include <linux/kernel.h>
23 #include <linux/ktime.h>
24 #include <linux/module.h>
25 #include <linux/of.h>
26 #include <linux/pinctrl/consumer.h>
27 #include <linux/platform_device.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/reset.h>
30
31 #define BYTES_PER_FIFO_WORD 4
32
33 #define I2C_CNFG 0x000
34 #define I2C_CNFG_DEBOUNCE_CNT GENMASK(14, 12)
35 #define I2C_CNFG_PACKET_MODE_EN BIT(10)
36 #define I2C_CNFG_NEW_MASTER_FSM BIT(11)
37 #define I2C_CNFG_MULTI_MASTER_MODE BIT(17)
38 #define I2C_STATUS 0x01c
39 #define I2C_SL_CNFG 0x020
40 #define I2C_SL_CNFG_NACK BIT(1)
41 #define I2C_SL_CNFG_NEWSL BIT(2)
42 #define I2C_SL_ADDR1 0x02c
43 #define I2C_SL_ADDR2 0x030
44 #define I2C_TLOW_SEXT 0x034
45 #define I2C_TX_FIFO 0x050
46 #define I2C_RX_FIFO 0x054
47 #define I2C_PACKET_TRANSFER_STATUS 0x058
48 #define I2C_FIFO_CONTROL 0x05c
49 #define I2C_FIFO_CONTROL_TX_FLUSH BIT(1)
50 #define I2C_FIFO_CONTROL_RX_FLUSH BIT(0)
51 #define I2C_FIFO_CONTROL_TX_TRIG(x) (((x) - 1) << 5)
52 #define I2C_FIFO_CONTROL_RX_TRIG(x) (((x) - 1) << 2)
53 #define I2C_FIFO_STATUS 0x060
54 #define I2C_FIFO_STATUS_TX GENMASK(7, 4)
55 #define I2C_FIFO_STATUS_RX GENMASK(3, 0)
56 #define I2C_INT_MASK 0x064
57 #define I2C_INT_STATUS 0x068
58 #define I2C_INT_BUS_CLR_DONE BIT(11)
59 #define I2C_INT_PACKET_XFER_COMPLETE BIT(7)
60 #define I2C_INT_NO_ACK BIT(3)
61 #define I2C_INT_ARBITRATION_LOST BIT(2)
62 #define I2C_INT_TX_FIFO_DATA_REQ BIT(1)
63 #define I2C_INT_RX_FIFO_DATA_REQ BIT(0)
64 #define I2C_CLK_DIVISOR 0x06c
65 #define I2C_CLK_DIVISOR_STD_FAST_MODE GENMASK(31, 16)
66 #define I2C_CLK_DIVISOR_HSMODE GENMASK(15, 0)
67
68 #define DVC_CTRL_REG1 0x000
69 #define DVC_CTRL_REG1_INTR_EN BIT(10)
70 #define DVC_CTRL_REG3 0x008
71 #define DVC_CTRL_REG3_SW_PROG BIT(26)
72 #define DVC_CTRL_REG3_I2C_DONE_INTR_EN BIT(30)
73 #define DVC_STATUS 0x00c
74 #define DVC_STATUS_I2C_DONE_INTR BIT(30)
75
76 #define I2C_ERR_NONE 0x00
77 #define I2C_ERR_NO_ACK BIT(0)
78 #define I2C_ERR_ARBITRATION_LOST BIT(1)
79 #define I2C_ERR_UNKNOWN_INTERRUPT BIT(2)
80 #define I2C_ERR_RX_BUFFER_OVERFLOW BIT(3)
81
82 #define PACKET_HEADER0_HEADER_SIZE GENMASK(29, 28)
83 #define PACKET_HEADER0_PACKET_ID GENMASK(23, 16)
84 #define PACKET_HEADER0_CONT_ID GENMASK(15, 12)
85 #define PACKET_HEADER0_PROTOCOL GENMASK(7, 4)
86 #define PACKET_HEADER0_PROTOCOL_I2C 1
87
88 #define I2C_HEADER_CONT_ON_NAK BIT(21)
89 #define I2C_HEADER_READ BIT(19)
90 #define I2C_HEADER_10BIT_ADDR BIT(18)
91 #define I2C_HEADER_IE_ENABLE BIT(17)
92 #define I2C_HEADER_REPEAT_START BIT(16)
93 #define I2C_HEADER_CONTINUE_XFER BIT(15)
94 #define I2C_HEADER_SLAVE_ADDR_SHIFT 1
95
96 #define I2C_BUS_CLEAR_CNFG 0x084
97 #define I2C_BC_SCLK_THRESHOLD GENMASK(23, 16)
98 #define I2C_BC_STOP_COND BIT(2)
99 #define I2C_BC_TERMINATE BIT(1)
100 #define I2C_BC_ENABLE BIT(0)
101 #define I2C_BUS_CLEAR_STATUS 0x088
102 #define I2C_BC_STATUS BIT(0)
103
104 #define I2C_CONFIG_LOAD 0x08c
105 #define I2C_MSTR_CONFIG_LOAD BIT(0)
106
107 #define I2C_CLKEN_OVERRIDE 0x090
108 #define I2C_MST_CORE_CLKEN_OVR BIT(0)
109
110 #define I2C_INTERFACE_TIMING_0 0x094
111 #define I2C_INTERFACE_TIMING_THIGH GENMASK(13, 8)
112 #define I2C_INTERFACE_TIMING_TLOW GENMASK(5, 0)
113 #define I2C_INTERFACE_TIMING_1 0x098
114 #define I2C_INTERFACE_TIMING_TBUF GENMASK(29, 24)
115 #define I2C_INTERFACE_TIMING_TSU_STO GENMASK(21, 16)
116 #define I2C_INTERFACE_TIMING_THD_STA GENMASK(13, 8)
117 #define I2C_INTERFACE_TIMING_TSU_STA GENMASK(5, 0)
118
119 #define I2C_HS_INTERFACE_TIMING_0 0x09c
120 #define I2C_HS_INTERFACE_TIMING_THIGH GENMASK(13, 8)
121 #define I2C_HS_INTERFACE_TIMING_TLOW GENMASK(5, 0)
122 #define I2C_HS_INTERFACE_TIMING_1 0x0a0
123 #define I2C_HS_INTERFACE_TIMING_TSU_STO GENMASK(21, 16)
124 #define I2C_HS_INTERFACE_TIMING_THD_STA GENMASK(13, 8)
125 #define I2C_HS_INTERFACE_TIMING_TSU_STA GENMASK(5, 0)
126
127 #define I2C_MST_FIFO_CONTROL 0x0b4
128 #define I2C_MST_FIFO_CONTROL_RX_FLUSH BIT(0)
129 #define I2C_MST_FIFO_CONTROL_TX_FLUSH BIT(1)
130 #define I2C_MST_FIFO_CONTROL_RX_TRIG(x) (((x) - 1) << 4)
131 #define I2C_MST_FIFO_CONTROL_TX_TRIG(x) (((x) - 1) << 16)
132
133 #define I2C_MST_FIFO_STATUS 0x0b8
134 #define I2C_MST_FIFO_STATUS_TX GENMASK(23, 16)
135 #define I2C_MST_FIFO_STATUS_RX GENMASK(7, 0)
136
137 /* configuration load timeout in microseconds */
138 #define I2C_CONFIG_LOAD_TIMEOUT 1000000
139
140 /* packet header size in bytes */
141 #define I2C_PACKET_HEADER_SIZE 12
142
143 /*
144 * I2C Controller will use PIO mode for transfers up to 32 bytes in order to
145 * avoid DMA overhead, otherwise external APB DMA controller will be used.
146 * Note that the actual MAX PIO length is 20 bytes because 32 bytes include
147 * I2C_PACKET_HEADER_SIZE.
148 */
149 #define I2C_PIO_MODE_PREFERRED_LEN 32
150
151 /*
152 * msg_end_type: The bus control which needs to be sent at end of transfer.
153 * @MSG_END_STOP: Send stop pulse.
154 * @MSG_END_REPEAT_START: Send repeat-start.
155 * @MSG_END_CONTINUE: Don't send stop or repeat-start.
156 */
157 enum msg_end_type {
158 MSG_END_STOP,
159 MSG_END_REPEAT_START,
160 MSG_END_CONTINUE,
161 };
162
163 /**
164 * struct tegra_i2c_hw_feature : per hardware generation features
165 * @has_continue_xfer_support: continue-transfer supported
166 * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer
167 * completion interrupt on per packet basis.
168 * @has_config_load_reg: Has the config load register to load the new
169 * configuration.
170 * @clk_divisor_hs_mode: Clock divisor in HS mode.
171 * @clk_divisor_std_mode: Clock divisor in standard mode. It is
172 * applicable if there is no fast clock source i.e. single clock
173 * source.
174 * @clk_divisor_fast_mode: Clock divisor in fast mode. It is
175 * applicable if there is no fast clock source i.e. single clock
176 * source.
177 * @clk_divisor_fast_plus_mode: Clock divisor in fast mode plus. It is
178 * applicable if there is no fast clock source (i.e. single
179 * clock source).
180 * @has_multi_master_mode: The I2C controller supports running in single-master
181 * or multi-master mode.
182 * @has_slcg_override_reg: The I2C controller supports a register that
183 * overrides the second level clock gating.
184 * @has_mst_fifo: The I2C controller contains the new MST FIFO interface that
185 * provides additional features and allows for longer messages to
186 * be transferred in one go.
187 * @quirks: I2C adapter quirks for limiting write/read transfer size and not
188 * allowing 0 length transfers.
189 * @supports_bus_clear: Bus Clear support to recover from bus hang during
190 * SDA stuck low from device for some unknown reasons.
191 * @has_apb_dma: Support of APBDMA on corresponding Tegra chip.
192 * @tlow_std_mode: Low period of the clock in standard mode.
193 * @thigh_std_mode: High period of the clock in standard mode.
194 * @tlow_fast_fastplus_mode: Low period of the clock in fast/fast-plus modes.
195 * @thigh_fast_fastplus_mode: High period of the clock in fast/fast-plus modes.
196 * @setup_hold_time_std_mode: Setup and hold time for start and stop conditions
197 * in standard mode.
198 * @setup_hold_time_fast_fast_plus_mode: Setup and hold time for start and stop
199 * conditions in fast/fast-plus modes.
200 * @setup_hold_time_hs_mode: Setup and hold time for start and stop conditions
201 * in HS mode.
202 * @has_interface_timing_reg: Has interface timing register to program the tuned
203 * timing settings.
204 */
205 struct tegra_i2c_hw_feature {
206 bool has_continue_xfer_support;
207 bool has_per_pkt_xfer_complete_irq;
208 bool has_config_load_reg;
209 u32 clk_divisor_hs_mode;
210 u32 clk_divisor_std_mode;
211 u32 clk_divisor_fast_mode;
212 u32 clk_divisor_fast_plus_mode;
213 bool has_multi_master_mode;
214 bool has_slcg_override_reg;
215 bool has_mst_fifo;
216 const struct i2c_adapter_quirks *quirks;
217 bool supports_bus_clear;
218 bool has_apb_dma;
219 u32 tlow_std_mode;
220 u32 thigh_std_mode;
221 u32 tlow_fast_fastplus_mode;
222 u32 thigh_fast_fastplus_mode;
223 u32 setup_hold_time_std_mode;
224 u32 setup_hold_time_fast_fast_plus_mode;
225 u32 setup_hold_time_hs_mode;
226 bool has_interface_timing_reg;
227 };
228
229 /**
230 * struct tegra_i2c_dev - per device I2C context
231 * @dev: device reference for power management
232 * @hw: Tegra I2C HW feature
233 * @adapter: core I2C layer adapter information
234 * @div_clk: clock reference for div clock of I2C controller
235 * @clocks: array of I2C controller clocks
236 * @nclocks: number of clocks in the array
237 * @rst: reset control for the I2C controller
238 * @base: ioremapped registers cookie
239 * @base_phys: physical base address of the I2C controller
240 * @cont_id: I2C controller ID, used for packet header
241 * @irq: IRQ number of transfer complete interrupt
242 * @is_dvc: identifies the DVC I2C controller, has a different register layout
243 * @is_vi: identifies the VI I2C controller, has a different register layout
244 * @msg_complete: transfer completion notifier
245 * @msg_buf_remaining: size of unsent data in the message buffer
246 * @msg_len: length of message in current transfer
247 * @msg_err: error code for completed message
248 * @msg_buf: pointer to current message data
249 * @msg_read: indicates that the transfer is a read access
250 * @timings: i2c timings information like bus frequency
251 * @multimaster_mode: indicates that I2C controller is in multi-master mode
252 * @dma_chan: DMA channel
253 * @dma_phys: handle to DMA resources
254 * @dma_buf: pointer to allocated DMA buffer
255 * @dma_buf_size: DMA buffer size
256 * @dma_mode: indicates active DMA transfer
257 * @dma_complete: DMA completion notifier
258 * @atomic_mode: indicates active atomic transfer
259 */
260 struct tegra_i2c_dev {
261 struct device *dev;
262 struct i2c_adapter adapter;
263
264 const struct tegra_i2c_hw_feature *hw;
265 struct reset_control *rst;
266 unsigned int cont_id;
267 unsigned int irq;
268
269 phys_addr_t base_phys;
270 void __iomem *base;
271
272 struct clk_bulk_data clocks[2];
273 unsigned int nclocks;
274
275 struct clk *div_clk;
276 struct i2c_timings timings;
277
278 struct completion msg_complete;
279 size_t msg_buf_remaining;
280 unsigned int msg_len;
281 int msg_err;
282 u8 *msg_buf;
283
284 struct completion dma_complete;
285 struct dma_chan *dma_chan;
286 unsigned int dma_buf_size;
287 struct device *dma_dev;
288 dma_addr_t dma_phys;
289 void *dma_buf;
290
291 bool multimaster_mode;
292 bool atomic_mode;
293 bool dma_mode;
294 bool msg_read;
295 bool is_dvc;
296 bool is_vi;
297 };
298
299 #define IS_DVC(dev) (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC) && (dev)->is_dvc)
300 #define IS_VI(dev) (IS_ENABLED(CONFIG_ARCH_TEGRA_210_SOC) && (dev)->is_vi)
301
dvc_writel(struct tegra_i2c_dev * i2c_dev,u32 val,unsigned int reg)302 static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
303 unsigned int reg)
304 {
305 writel_relaxed(val, i2c_dev->base + reg);
306 }
307
dvc_readl(struct tegra_i2c_dev * i2c_dev,unsigned int reg)308 static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned int reg)
309 {
310 return readl_relaxed(i2c_dev->base + reg);
311 }
312
313 /*
314 * If necessary, i2c_writel() and i2c_readl() will offset the register
315 * in order to talk to the I2C block inside the DVC block.
316 */
tegra_i2c_reg_addr(struct tegra_i2c_dev * i2c_dev,unsigned int reg)317 static u32 tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev, unsigned int reg)
318 {
319 if (IS_DVC(i2c_dev))
320 reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
321 else if (IS_VI(i2c_dev))
322 reg = 0xc00 + (reg << 2);
323
324 return reg;
325 }
326
i2c_writel(struct tegra_i2c_dev * i2c_dev,u32 val,unsigned int reg)327 static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned int reg)
328 {
329 writel_relaxed(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
330
331 /* read back register to make sure that register writes completed */
332 if (reg != I2C_TX_FIFO)
333 readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
334 else if (IS_VI(i2c_dev))
335 readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, I2C_INT_STATUS));
336 }
337
i2c_readl(struct tegra_i2c_dev * i2c_dev,unsigned int reg)338 static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned int reg)
339 {
340 return readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
341 }
342
i2c_writesl(struct tegra_i2c_dev * i2c_dev,void * data,unsigned int reg,unsigned int len)343 static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
344 unsigned int reg, unsigned int len)
345 {
346 writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
347 }
348
i2c_writesl_vi(struct tegra_i2c_dev * i2c_dev,void * data,unsigned int reg,unsigned int len)349 static void i2c_writesl_vi(struct tegra_i2c_dev *i2c_dev, void *data,
350 unsigned int reg, unsigned int len)
351 {
352 u32 *data32 = data;
353
354 /*
355 * VI I2C controller has known hardware bug where writes get stuck
356 * when immediate multiple writes happen to TX_FIFO register.
357 * Recommended software work around is to read I2C register after
358 * each write to TX_FIFO register to flush out the data.
359 */
360 while (len--)
361 i2c_writel(i2c_dev, *data32++, reg);
362 }
363
i2c_readsl(struct tegra_i2c_dev * i2c_dev,void * data,unsigned int reg,unsigned int len)364 static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
365 unsigned int reg, unsigned int len)
366 {
367 readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
368 }
369
tegra_i2c_mask_irq(struct tegra_i2c_dev * i2c_dev,u32 mask)370 static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
371 {
372 u32 int_mask;
373
374 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) & ~mask;
375 i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
376 }
377
tegra_i2c_unmask_irq(struct tegra_i2c_dev * i2c_dev,u32 mask)378 static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
379 {
380 u32 int_mask;
381
382 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK) | mask;
383 i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
384 }
385
tegra_i2c_dma_complete(void * args)386 static void tegra_i2c_dma_complete(void *args)
387 {
388 struct tegra_i2c_dev *i2c_dev = args;
389
390 complete(&i2c_dev->dma_complete);
391 }
392
tegra_i2c_dma_submit(struct tegra_i2c_dev * i2c_dev,size_t len)393 static int tegra_i2c_dma_submit(struct tegra_i2c_dev *i2c_dev, size_t len)
394 {
395 struct dma_async_tx_descriptor *dma_desc;
396 enum dma_transfer_direction dir;
397
398 dev_dbg(i2c_dev->dev, "starting DMA for length: %zu\n", len);
399
400 reinit_completion(&i2c_dev->dma_complete);
401
402 dir = i2c_dev->msg_read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
403
404 dma_desc = dmaengine_prep_slave_single(i2c_dev->dma_chan, i2c_dev->dma_phys,
405 len, dir, DMA_PREP_INTERRUPT |
406 DMA_CTRL_ACK);
407 if (!dma_desc) {
408 dev_err(i2c_dev->dev, "failed to get %s DMA descriptor\n",
409 i2c_dev->msg_read ? "RX" : "TX");
410 return -EINVAL;
411 }
412
413 dma_desc->callback = tegra_i2c_dma_complete;
414 dma_desc->callback_param = i2c_dev;
415
416 dmaengine_submit(dma_desc);
417 dma_async_issue_pending(i2c_dev->dma_chan);
418
419 return 0;
420 }
421
tegra_i2c_release_dma(struct tegra_i2c_dev * i2c_dev)422 static void tegra_i2c_release_dma(struct tegra_i2c_dev *i2c_dev)
423 {
424 if (i2c_dev->dma_buf) {
425 dma_free_coherent(i2c_dev->dma_dev, i2c_dev->dma_buf_size,
426 i2c_dev->dma_buf, i2c_dev->dma_phys);
427 i2c_dev->dma_buf = NULL;
428 }
429
430 if (i2c_dev->dma_chan) {
431 dma_release_channel(i2c_dev->dma_chan);
432 i2c_dev->dma_chan = NULL;
433 }
434 }
435
tegra_i2c_init_dma(struct tegra_i2c_dev * i2c_dev)436 static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev)
437 {
438 dma_addr_t dma_phys;
439 u32 *dma_buf;
440 int err;
441
442 if (IS_VI(i2c_dev))
443 return 0;
444
445 if (i2c_dev->hw->has_apb_dma) {
446 if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA)) {
447 dev_dbg(i2c_dev->dev, "APB DMA support not enabled\n");
448 return 0;
449 }
450 } else if (!IS_ENABLED(CONFIG_TEGRA186_GPC_DMA)) {
451 dev_dbg(i2c_dev->dev, "GPC DMA support not enabled\n");
452 return 0;
453 }
454
455 /*
456 * The same channel will be used for both RX and TX.
457 * Keeping the name as "tx" for backward compatibility
458 * with existing devicetrees.
459 */
460 i2c_dev->dma_chan = dma_request_chan(i2c_dev->dev, "tx");
461 if (IS_ERR(i2c_dev->dma_chan)) {
462 err = PTR_ERR(i2c_dev->dma_chan);
463 i2c_dev->dma_chan = NULL;
464 goto err_out;
465 }
466
467 i2c_dev->dma_dev = i2c_dev->dma_chan->device->dev;
468 i2c_dev->dma_buf_size = i2c_dev->hw->quirks->max_write_len +
469 I2C_PACKET_HEADER_SIZE;
470
471 dma_buf = dma_alloc_coherent(i2c_dev->dma_dev, i2c_dev->dma_buf_size,
472 &dma_phys, GFP_KERNEL | __GFP_NOWARN);
473 if (!dma_buf) {
474 dev_err(i2c_dev->dev, "failed to allocate DMA buffer\n");
475 err = -ENOMEM;
476 goto err_out;
477 }
478
479 i2c_dev->dma_buf = dma_buf;
480 i2c_dev->dma_phys = dma_phys;
481
482 return 0;
483
484 err_out:
485 tegra_i2c_release_dma(i2c_dev);
486 if (err != -EPROBE_DEFER) {
487 dev_err(i2c_dev->dev, "cannot use DMA: %d\n", err);
488 dev_err(i2c_dev->dev, "falling back to PIO\n");
489 return 0;
490 }
491
492 return err;
493 }
494
495 /*
496 * One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
497 * block. This block is identical to the rest of the I2C blocks, except that
498 * it only supports master mode, it has registers moved around, and it needs
499 * some extra init to get it into I2C mode. The register moves are handled
500 * by i2c_readl() and i2c_writel().
501 */
tegra_dvc_init(struct tegra_i2c_dev * i2c_dev)502 static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
503 {
504 u32 val;
505
506 val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
507 val |= DVC_CTRL_REG3_SW_PROG;
508 val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
509 dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
510
511 val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
512 val |= DVC_CTRL_REG1_INTR_EN;
513 dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
514 }
515
tegra_i2c_vi_init(struct tegra_i2c_dev * i2c_dev)516 static void tegra_i2c_vi_init(struct tegra_i2c_dev *i2c_dev)
517 {
518 u32 value;
519
520 value = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, 2) |
521 FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, 4);
522 i2c_writel(i2c_dev, value, I2C_INTERFACE_TIMING_0);
523
524 value = FIELD_PREP(I2C_INTERFACE_TIMING_TBUF, 4) |
525 FIELD_PREP(I2C_INTERFACE_TIMING_TSU_STO, 7) |
526 FIELD_PREP(I2C_INTERFACE_TIMING_THD_STA, 4) |
527 FIELD_PREP(I2C_INTERFACE_TIMING_TSU_STA, 4);
528 i2c_writel(i2c_dev, value, I2C_INTERFACE_TIMING_1);
529
530 value = FIELD_PREP(I2C_HS_INTERFACE_TIMING_THIGH, 3) |
531 FIELD_PREP(I2C_HS_INTERFACE_TIMING_TLOW, 8);
532 i2c_writel(i2c_dev, value, I2C_HS_INTERFACE_TIMING_0);
533
534 value = FIELD_PREP(I2C_HS_INTERFACE_TIMING_TSU_STO, 11) |
535 FIELD_PREP(I2C_HS_INTERFACE_TIMING_THD_STA, 11) |
536 FIELD_PREP(I2C_HS_INTERFACE_TIMING_TSU_STA, 11);
537 i2c_writel(i2c_dev, value, I2C_HS_INTERFACE_TIMING_1);
538
539 value = FIELD_PREP(I2C_BC_SCLK_THRESHOLD, 9) | I2C_BC_STOP_COND;
540 i2c_writel(i2c_dev, value, I2C_BUS_CLEAR_CNFG);
541
542 i2c_writel(i2c_dev, 0x0, I2C_TLOW_SEXT);
543 }
544
tegra_i2c_poll_register(struct tegra_i2c_dev * i2c_dev,u32 reg,u32 mask,u32 delay_us,u32 timeout_us)545 static int tegra_i2c_poll_register(struct tegra_i2c_dev *i2c_dev,
546 u32 reg, u32 mask, u32 delay_us,
547 u32 timeout_us)
548 {
549 void __iomem *addr = i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg);
550 u32 val;
551
552 if (!i2c_dev->atomic_mode)
553 return readl_relaxed_poll_timeout(addr, val, !(val & mask),
554 delay_us, timeout_us);
555
556 return readl_relaxed_poll_timeout_atomic(addr, val, !(val & mask),
557 delay_us, timeout_us);
558 }
559
tegra_i2c_flush_fifos(struct tegra_i2c_dev * i2c_dev)560 static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
561 {
562 u32 mask, val, offset;
563 int err;
564
565 if (i2c_dev->hw->has_mst_fifo) {
566 mask = I2C_MST_FIFO_CONTROL_TX_FLUSH |
567 I2C_MST_FIFO_CONTROL_RX_FLUSH;
568 offset = I2C_MST_FIFO_CONTROL;
569 } else {
570 mask = I2C_FIFO_CONTROL_TX_FLUSH |
571 I2C_FIFO_CONTROL_RX_FLUSH;
572 offset = I2C_FIFO_CONTROL;
573 }
574
575 val = i2c_readl(i2c_dev, offset);
576 val |= mask;
577 i2c_writel(i2c_dev, val, offset);
578
579 err = tegra_i2c_poll_register(i2c_dev, offset, mask, 1000, 1000000);
580 if (err) {
581 dev_err(i2c_dev->dev, "failed to flush FIFO\n");
582 return err;
583 }
584
585 return 0;
586 }
587
tegra_i2c_wait_for_config_load(struct tegra_i2c_dev * i2c_dev)588 static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
589 {
590 int err;
591
592 if (!i2c_dev->hw->has_config_load_reg)
593 return 0;
594
595 i2c_writel(i2c_dev, I2C_MSTR_CONFIG_LOAD, I2C_CONFIG_LOAD);
596
597 err = tegra_i2c_poll_register(i2c_dev, I2C_CONFIG_LOAD, 0xffffffff,
598 1000, I2C_CONFIG_LOAD_TIMEOUT);
599 if (err) {
600 dev_err(i2c_dev->dev, "failed to load config\n");
601 return err;
602 }
603
604 return 0;
605 }
606
tegra_i2c_init(struct tegra_i2c_dev * i2c_dev)607 static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
608 {
609 u32 val, clk_divisor, clk_multiplier, tsu_thd, tlow, thigh, non_hs_mode;
610 acpi_handle handle = ACPI_HANDLE(i2c_dev->dev);
611 struct i2c_timings *t = &i2c_dev->timings;
612 int err;
613
614 /*
615 * The reset shouldn't ever fail in practice. The failure will be a
616 * sign of a severe problem that needs to be resolved. Still we don't
617 * want to fail the initialization completely because this may break
618 * kernel boot up since voltage regulators use I2C. Hence, we will
619 * emit a noisy warning on error, which won't stay unnoticed and
620 * won't hose machine entirely.
621 */
622 if (handle)
623 err = acpi_evaluate_object(handle, "_RST", NULL, NULL);
624 else
625 err = reset_control_reset(i2c_dev->rst);
626
627 WARN_ON_ONCE(err);
628
629 if (IS_DVC(i2c_dev))
630 tegra_dvc_init(i2c_dev);
631
632 val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN |
633 FIELD_PREP(I2C_CNFG_DEBOUNCE_CNT, 2);
634
635 if (i2c_dev->hw->has_multi_master_mode)
636 val |= I2C_CNFG_MULTI_MASTER_MODE;
637
638 i2c_writel(i2c_dev, val, I2C_CNFG);
639 i2c_writel(i2c_dev, 0, I2C_INT_MASK);
640
641 if (IS_VI(i2c_dev))
642 tegra_i2c_vi_init(i2c_dev);
643
644 switch (t->bus_freq_hz) {
645 case I2C_MAX_STANDARD_MODE_FREQ + 1 ... I2C_MAX_FAST_MODE_PLUS_FREQ:
646 default:
647 tlow = i2c_dev->hw->tlow_fast_fastplus_mode;
648 thigh = i2c_dev->hw->thigh_fast_fastplus_mode;
649 tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode;
650
651 if (t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ)
652 non_hs_mode = i2c_dev->hw->clk_divisor_fast_plus_mode;
653 else
654 non_hs_mode = i2c_dev->hw->clk_divisor_fast_mode;
655 break;
656
657 case 0 ... I2C_MAX_STANDARD_MODE_FREQ:
658 tlow = i2c_dev->hw->tlow_std_mode;
659 thigh = i2c_dev->hw->thigh_std_mode;
660 tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
661 non_hs_mode = i2c_dev->hw->clk_divisor_std_mode;
662 break;
663 }
664
665 /* make sure clock divisor programmed correctly */
666 clk_divisor = FIELD_PREP(I2C_CLK_DIVISOR_HSMODE,
667 i2c_dev->hw->clk_divisor_hs_mode) |
668 FIELD_PREP(I2C_CLK_DIVISOR_STD_FAST_MODE, non_hs_mode);
669 i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
670
671 if (i2c_dev->hw->has_interface_timing_reg) {
672 val = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, thigh) |
673 FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, tlow);
674 i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
675 }
676
677 /*
678 * Configure setup and hold times only when tsu_thd is non-zero.
679 * Otherwise, preserve the chip default values.
680 */
681 if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
682 i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
683
684 clk_multiplier = (tlow + thigh + 2) * (non_hs_mode + 1);
685
686 err = clk_set_rate(i2c_dev->div_clk,
687 t->bus_freq_hz * clk_multiplier);
688 if (err) {
689 dev_err(i2c_dev->dev, "failed to set div-clk rate: %d\n", err);
690 return err;
691 }
692
693 if (!IS_DVC(i2c_dev) && !IS_VI(i2c_dev)) {
694 u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
695
696 sl_cfg |= I2C_SL_CNFG_NACK | I2C_SL_CNFG_NEWSL;
697 i2c_writel(i2c_dev, sl_cfg, I2C_SL_CNFG);
698 i2c_writel(i2c_dev, 0xfc, I2C_SL_ADDR1);
699 i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
700 }
701
702 err = tegra_i2c_flush_fifos(i2c_dev);
703 if (err)
704 return err;
705
706 if (i2c_dev->multimaster_mode && i2c_dev->hw->has_slcg_override_reg)
707 i2c_writel(i2c_dev, I2C_MST_CORE_CLKEN_OVR, I2C_CLKEN_OVERRIDE);
708
709 err = tegra_i2c_wait_for_config_load(i2c_dev);
710 if (err)
711 return err;
712
713 return 0;
714 }
715
tegra_i2c_disable_packet_mode(struct tegra_i2c_dev * i2c_dev)716 static int tegra_i2c_disable_packet_mode(struct tegra_i2c_dev *i2c_dev)
717 {
718 u32 cnfg;
719
720 /*
721 * NACK interrupt is generated before the I2C controller generates
722 * the STOP condition on the bus. So, wait for 2 clock periods
723 * before disabling the controller so that the STOP condition has
724 * been delivered properly.
725 */
726 udelay(DIV_ROUND_UP(2 * 1000000, i2c_dev->timings.bus_freq_hz));
727
728 cnfg = i2c_readl(i2c_dev, I2C_CNFG);
729 if (cnfg & I2C_CNFG_PACKET_MODE_EN)
730 i2c_writel(i2c_dev, cnfg & ~I2C_CNFG_PACKET_MODE_EN, I2C_CNFG);
731
732 return tegra_i2c_wait_for_config_load(i2c_dev);
733 }
734
tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev * i2c_dev)735 static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
736 {
737 size_t buf_remaining = i2c_dev->msg_buf_remaining;
738 unsigned int words_to_transfer, rx_fifo_avail;
739 u8 *buf = i2c_dev->msg_buf;
740 u32 val;
741
742 /*
743 * Catch overflow due to message fully sent before the check for
744 * RX FIFO availability.
745 */
746 if (WARN_ON_ONCE(!(i2c_dev->msg_buf_remaining)))
747 return -EINVAL;
748
749 if (i2c_dev->hw->has_mst_fifo) {
750 val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
751 rx_fifo_avail = FIELD_GET(I2C_MST_FIFO_STATUS_RX, val);
752 } else {
753 val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
754 rx_fifo_avail = FIELD_GET(I2C_FIFO_STATUS_RX, val);
755 }
756
757 /* round down to exclude partial word at the end of buffer */
758 words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
759 if (words_to_transfer > rx_fifo_avail)
760 words_to_transfer = rx_fifo_avail;
761
762 i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
763
764 buf += words_to_transfer * BYTES_PER_FIFO_WORD;
765 buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
766 rx_fifo_avail -= words_to_transfer;
767
768 /*
769 * If there is a partial word at the end of buffer, handle it
770 * manually to prevent overwriting past the end of buffer.
771 */
772 if (rx_fifo_avail > 0 && buf_remaining > 0) {
773 /*
774 * buf_remaining > 3 check not needed as rx_fifo_avail == 0
775 * when (words_to_transfer was > rx_fifo_avail) earlier
776 * in this function.
777 */
778 val = i2c_readl(i2c_dev, I2C_RX_FIFO);
779 val = cpu_to_le32(val);
780 memcpy(buf, &val, buf_remaining);
781 buf_remaining = 0;
782 rx_fifo_avail--;
783 }
784
785 /* RX FIFO must be drained, otherwise it's an Overflow case. */
786 if (WARN_ON_ONCE(rx_fifo_avail))
787 return -EINVAL;
788
789 i2c_dev->msg_buf_remaining = buf_remaining;
790 i2c_dev->msg_buf = buf;
791
792 return 0;
793 }
794
tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev * i2c_dev)795 static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
796 {
797 size_t buf_remaining = i2c_dev->msg_buf_remaining;
798 unsigned int words_to_transfer, tx_fifo_avail;
799 u8 *buf = i2c_dev->msg_buf;
800 u32 val;
801
802 if (i2c_dev->hw->has_mst_fifo) {
803 val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
804 tx_fifo_avail = FIELD_GET(I2C_MST_FIFO_STATUS_TX, val);
805 } else {
806 val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
807 tx_fifo_avail = FIELD_GET(I2C_FIFO_STATUS_TX, val);
808 }
809
810 /* round down to exclude partial word at the end of buffer */
811 words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
812
813 /*
814 * This hunk pushes 4 bytes at a time into the TX FIFO.
815 *
816 * It's very common to have < 4 bytes, hence there is no word
817 * to push if we have less than 4 bytes to transfer.
818 */
819 if (words_to_transfer) {
820 if (words_to_transfer > tx_fifo_avail)
821 words_to_transfer = tx_fifo_avail;
822
823 /*
824 * Update state before writing to FIFO. Note that this may
825 * cause us to finish writing all bytes (AKA buf_remaining
826 * goes to 0), hence we have a potential for an interrupt
827 * (PACKET_XFER_COMPLETE is not maskable), but GIC interrupt
828 * is disabled at this point.
829 */
830 buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
831 tx_fifo_avail -= words_to_transfer;
832
833 i2c_dev->msg_buf_remaining = buf_remaining;
834 i2c_dev->msg_buf = buf + words_to_transfer * BYTES_PER_FIFO_WORD;
835
836 if (IS_VI(i2c_dev))
837 i2c_writesl_vi(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
838 else
839 i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
840
841 buf += words_to_transfer * BYTES_PER_FIFO_WORD;
842 }
843
844 /*
845 * If there is a partial word at the end of buffer, handle it manually
846 * to prevent reading past the end of buffer, which could cross a page
847 * boundary and fault.
848 */
849 if (tx_fifo_avail > 0 && buf_remaining > 0) {
850 /*
851 * buf_remaining > 3 check not needed as tx_fifo_avail == 0
852 * when (words_to_transfer was > tx_fifo_avail) earlier
853 * in this function for non-zero words_to_transfer.
854 */
855 memcpy(&val, buf, buf_remaining);
856 val = le32_to_cpu(val);
857
858 i2c_dev->msg_buf_remaining = 0;
859 i2c_dev->msg_buf = NULL;
860
861 i2c_writel(i2c_dev, val, I2C_TX_FIFO);
862 }
863
864 return 0;
865 }
866
tegra_i2c_isr(int irq,void * dev_id)867 static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
868 {
869 const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
870 struct tegra_i2c_dev *i2c_dev = dev_id;
871 u32 status;
872
873 status = i2c_readl(i2c_dev, I2C_INT_STATUS);
874
875 if (status == 0) {
876 dev_warn(i2c_dev->dev, "IRQ status 0 %08x %08x %08x\n",
877 i2c_readl(i2c_dev, I2C_PACKET_TRANSFER_STATUS),
878 i2c_readl(i2c_dev, I2C_STATUS),
879 i2c_readl(i2c_dev, I2C_CNFG));
880 i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
881 goto err;
882 }
883
884 if (status & status_err) {
885 tegra_i2c_disable_packet_mode(i2c_dev);
886 if (status & I2C_INT_NO_ACK)
887 i2c_dev->msg_err |= I2C_ERR_NO_ACK;
888 if (status & I2C_INT_ARBITRATION_LOST)
889 i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
890 goto err;
891 }
892
893 /*
894 * I2C transfer is terminated during the bus clear, so skip
895 * processing the other interrupts.
896 */
897 if (i2c_dev->hw->supports_bus_clear && (status & I2C_INT_BUS_CLR_DONE))
898 goto err;
899
900 if (!i2c_dev->dma_mode) {
901 if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
902 if (tegra_i2c_empty_rx_fifo(i2c_dev)) {
903 /*
904 * Overflow error condition: message fully sent,
905 * with no XFER_COMPLETE interrupt but hardware
906 * asks to transfer more.
907 */
908 i2c_dev->msg_err |= I2C_ERR_RX_BUFFER_OVERFLOW;
909 goto err;
910 }
911 }
912
913 if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
914 if (i2c_dev->msg_buf_remaining)
915 tegra_i2c_fill_tx_fifo(i2c_dev);
916 else
917 tegra_i2c_mask_irq(i2c_dev,
918 I2C_INT_TX_FIFO_DATA_REQ);
919 }
920 }
921
922 i2c_writel(i2c_dev, status, I2C_INT_STATUS);
923 if (IS_DVC(i2c_dev))
924 dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
925
926 /*
927 * During message read XFER_COMPLETE interrupt is triggered prior to
928 * DMA completion and during message write XFER_COMPLETE interrupt is
929 * triggered after DMA completion.
930 *
931 * PACKETS_XFER_COMPLETE indicates completion of all bytes of transfer,
932 * so forcing msg_buf_remaining to 0 in DMA mode.
933 */
934 if (status & I2C_INT_PACKET_XFER_COMPLETE) {
935 if (i2c_dev->dma_mode)
936 i2c_dev->msg_buf_remaining = 0;
937 /*
938 * Underflow error condition: XFER_COMPLETE before message
939 * fully sent.
940 */
941 if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
942 i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
943 goto err;
944 }
945 complete(&i2c_dev->msg_complete);
946 }
947 goto done;
948 err:
949 /* mask all interrupts on error */
950 tegra_i2c_mask_irq(i2c_dev,
951 I2C_INT_NO_ACK |
952 I2C_INT_ARBITRATION_LOST |
953 I2C_INT_PACKET_XFER_COMPLETE |
954 I2C_INT_TX_FIFO_DATA_REQ |
955 I2C_INT_RX_FIFO_DATA_REQ);
956
957 if (i2c_dev->hw->supports_bus_clear)
958 tegra_i2c_mask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
959
960 i2c_writel(i2c_dev, status, I2C_INT_STATUS);
961
962 if (IS_DVC(i2c_dev))
963 dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
964
965 if (i2c_dev->dma_mode) {
966 dmaengine_terminate_async(i2c_dev->dma_chan);
967 complete(&i2c_dev->dma_complete);
968 }
969
970 complete(&i2c_dev->msg_complete);
971 done:
972 return IRQ_HANDLED;
973 }
974
tegra_i2c_config_fifo_trig(struct tegra_i2c_dev * i2c_dev,size_t len)975 static void tegra_i2c_config_fifo_trig(struct tegra_i2c_dev *i2c_dev,
976 size_t len)
977 {
978 struct dma_slave_config slv_config = {0};
979 u32 val, reg, dma_burst, reg_offset;
980 int err;
981
982 if (i2c_dev->hw->has_mst_fifo)
983 reg = I2C_MST_FIFO_CONTROL;
984 else
985 reg = I2C_FIFO_CONTROL;
986
987 if (i2c_dev->dma_mode) {
988 if (len & 0xF)
989 dma_burst = 1;
990 else if (len & 0x10)
991 dma_burst = 4;
992 else
993 dma_burst = 8;
994
995 if (i2c_dev->msg_read) {
996 reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_RX_FIFO);
997
998 slv_config.src_addr = i2c_dev->base_phys + reg_offset;
999 slv_config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1000 slv_config.src_maxburst = dma_burst;
1001
1002 if (i2c_dev->hw->has_mst_fifo)
1003 val = I2C_MST_FIFO_CONTROL_RX_TRIG(dma_burst);
1004 else
1005 val = I2C_FIFO_CONTROL_RX_TRIG(dma_burst);
1006 } else {
1007 reg_offset = tegra_i2c_reg_addr(i2c_dev, I2C_TX_FIFO);
1008
1009 slv_config.dst_addr = i2c_dev->base_phys + reg_offset;
1010 slv_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1011 slv_config.dst_maxburst = dma_burst;
1012
1013 if (i2c_dev->hw->has_mst_fifo)
1014 val = I2C_MST_FIFO_CONTROL_TX_TRIG(dma_burst);
1015 else
1016 val = I2C_FIFO_CONTROL_TX_TRIG(dma_burst);
1017 }
1018
1019 slv_config.device_fc = true;
1020 err = dmaengine_slave_config(i2c_dev->dma_chan, &slv_config);
1021 if (err) {
1022 dev_err(i2c_dev->dev, "DMA config failed: %d\n", err);
1023 dev_err(i2c_dev->dev, "falling back to PIO\n");
1024
1025 tegra_i2c_release_dma(i2c_dev);
1026 i2c_dev->dma_mode = false;
1027 } else {
1028 goto out;
1029 }
1030 }
1031
1032 if (i2c_dev->hw->has_mst_fifo)
1033 val = I2C_MST_FIFO_CONTROL_TX_TRIG(8) |
1034 I2C_MST_FIFO_CONTROL_RX_TRIG(1);
1035 else
1036 val = I2C_FIFO_CONTROL_TX_TRIG(8) |
1037 I2C_FIFO_CONTROL_RX_TRIG(1);
1038 out:
1039 i2c_writel(i2c_dev, val, reg);
1040 }
1041
tegra_i2c_poll_completion(struct tegra_i2c_dev * i2c_dev,struct completion * complete,unsigned int timeout_ms)1042 static unsigned long tegra_i2c_poll_completion(struct tegra_i2c_dev *i2c_dev,
1043 struct completion *complete,
1044 unsigned int timeout_ms)
1045 {
1046 ktime_t ktime = ktime_get();
1047 ktime_t ktimeout = ktime_add_ms(ktime, timeout_ms);
1048
1049 do {
1050 u32 status = i2c_readl(i2c_dev, I2C_INT_STATUS);
1051
1052 if (status)
1053 tegra_i2c_isr(i2c_dev->irq, i2c_dev);
1054
1055 if (completion_done(complete)) {
1056 s64 delta = ktime_ms_delta(ktimeout, ktime);
1057
1058 return msecs_to_jiffies(delta) ?: 1;
1059 }
1060
1061 ktime = ktime_get();
1062
1063 } while (ktime_before(ktime, ktimeout));
1064
1065 return 0;
1066 }
1067
tegra_i2c_wait_completion(struct tegra_i2c_dev * i2c_dev,struct completion * complete,unsigned int timeout_ms)1068 static unsigned long tegra_i2c_wait_completion(struct tegra_i2c_dev *i2c_dev,
1069 struct completion *complete,
1070 unsigned int timeout_ms)
1071 {
1072 unsigned long ret;
1073
1074 if (i2c_dev->atomic_mode) {
1075 ret = tegra_i2c_poll_completion(i2c_dev, complete, timeout_ms);
1076 } else {
1077 enable_irq(i2c_dev->irq);
1078 ret = wait_for_completion_timeout(complete,
1079 msecs_to_jiffies(timeout_ms));
1080 disable_irq(i2c_dev->irq);
1081
1082 /*
1083 * Under some rare circumstances (like running KASAN +
1084 * NFS root) CPU, which handles interrupt, may stuck in
1085 * uninterruptible state for a significant time. In this
1086 * case we will get timeout if I2C transfer is running on
1087 * a sibling CPU, despite of IRQ being raised.
1088 *
1089 * In order to handle this rare condition, the IRQ status
1090 * needs to be checked after timeout.
1091 */
1092 if (ret == 0)
1093 ret = tegra_i2c_poll_completion(i2c_dev, complete, 0);
1094 }
1095
1096 return ret;
1097 }
1098
tegra_i2c_issue_bus_clear(struct i2c_adapter * adap)1099 static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap)
1100 {
1101 struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1102 u32 val, time_left;
1103 int err;
1104
1105 reinit_completion(&i2c_dev->msg_complete);
1106
1107 val = FIELD_PREP(I2C_BC_SCLK_THRESHOLD, 9) | I2C_BC_STOP_COND |
1108 I2C_BC_TERMINATE;
1109 i2c_writel(i2c_dev, val, I2C_BUS_CLEAR_CNFG);
1110
1111 err = tegra_i2c_wait_for_config_load(i2c_dev);
1112 if (err)
1113 return err;
1114
1115 val |= I2C_BC_ENABLE;
1116 i2c_writel(i2c_dev, val, I2C_BUS_CLEAR_CNFG);
1117 tegra_i2c_unmask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
1118
1119 time_left = tegra_i2c_wait_completion(i2c_dev, &i2c_dev->msg_complete, 50);
1120 tegra_i2c_mask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE);
1121
1122 if (time_left == 0) {
1123 dev_err(i2c_dev->dev, "failed to clear bus\n");
1124 return -ETIMEDOUT;
1125 }
1126
1127 val = i2c_readl(i2c_dev, I2C_BUS_CLEAR_STATUS);
1128 if (!(val & I2C_BC_STATUS)) {
1129 dev_err(i2c_dev->dev, "un-recovered arbitration lost\n");
1130 return -EIO;
1131 }
1132
1133 return -EAGAIN;
1134 }
1135
tegra_i2c_push_packet_header(struct tegra_i2c_dev * i2c_dev,struct i2c_msg * msg,enum msg_end_type end_state)1136 static void tegra_i2c_push_packet_header(struct tegra_i2c_dev *i2c_dev,
1137 struct i2c_msg *msg,
1138 enum msg_end_type end_state)
1139 {
1140 u32 *dma_buf = i2c_dev->dma_buf;
1141 u32 packet_header;
1142
1143 packet_header = FIELD_PREP(PACKET_HEADER0_HEADER_SIZE, 0) |
1144 FIELD_PREP(PACKET_HEADER0_PROTOCOL,
1145 PACKET_HEADER0_PROTOCOL_I2C) |
1146 FIELD_PREP(PACKET_HEADER0_CONT_ID, i2c_dev->cont_id) |
1147 FIELD_PREP(PACKET_HEADER0_PACKET_ID, 1);
1148
1149 if (i2c_dev->dma_mode && !i2c_dev->msg_read)
1150 *dma_buf++ = packet_header;
1151 else
1152 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1153
1154 packet_header = i2c_dev->msg_len - 1;
1155
1156 if (i2c_dev->dma_mode && !i2c_dev->msg_read)
1157 *dma_buf++ = packet_header;
1158 else
1159 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1160
1161 packet_header = I2C_HEADER_IE_ENABLE;
1162
1163 if (end_state == MSG_END_CONTINUE)
1164 packet_header |= I2C_HEADER_CONTINUE_XFER;
1165 else if (end_state == MSG_END_REPEAT_START)
1166 packet_header |= I2C_HEADER_REPEAT_START;
1167
1168 if (msg->flags & I2C_M_TEN) {
1169 packet_header |= msg->addr;
1170 packet_header |= I2C_HEADER_10BIT_ADDR;
1171 } else {
1172 packet_header |= msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
1173 }
1174
1175 if (msg->flags & I2C_M_IGNORE_NAK)
1176 packet_header |= I2C_HEADER_CONT_ON_NAK;
1177
1178 if (msg->flags & I2C_M_RD)
1179 packet_header |= I2C_HEADER_READ;
1180
1181 if (i2c_dev->dma_mode && !i2c_dev->msg_read)
1182 *dma_buf++ = packet_header;
1183 else
1184 i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
1185 }
1186
tegra_i2c_error_recover(struct tegra_i2c_dev * i2c_dev,struct i2c_msg * msg)1187 static int tegra_i2c_error_recover(struct tegra_i2c_dev *i2c_dev,
1188 struct i2c_msg *msg)
1189 {
1190 if (i2c_dev->msg_err == I2C_ERR_NONE)
1191 return 0;
1192
1193 tegra_i2c_init(i2c_dev);
1194
1195 /* start recovery upon arbitration loss in single master mode */
1196 if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) {
1197 if (!i2c_dev->multimaster_mode)
1198 return i2c_recover_bus(&i2c_dev->adapter);
1199
1200 return -EAGAIN;
1201 }
1202
1203 if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
1204 if (msg->flags & I2C_M_IGNORE_NAK)
1205 return 0;
1206
1207 return -EREMOTEIO;
1208 }
1209
1210 return -EIO;
1211 }
1212
tegra_i2c_xfer_msg(struct tegra_i2c_dev * i2c_dev,struct i2c_msg * msg,enum msg_end_type end_state)1213 static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
1214 struct i2c_msg *msg,
1215 enum msg_end_type end_state)
1216 {
1217 unsigned long time_left, xfer_time = 100;
1218 size_t xfer_size;
1219 u32 int_mask;
1220 int err;
1221
1222 err = tegra_i2c_flush_fifos(i2c_dev);
1223 if (err)
1224 return err;
1225
1226 i2c_dev->msg_buf = msg->buf;
1227 i2c_dev->msg_len = msg->len;
1228
1229 i2c_dev->msg_err = I2C_ERR_NONE;
1230 i2c_dev->msg_read = !!(msg->flags & I2C_M_RD);
1231 reinit_completion(&i2c_dev->msg_complete);
1232
1233 /*
1234 * For SMBUS block read command, read only 1 byte in the first transfer.
1235 * Adjust that 1 byte for the next transfer in the msg buffer and msg
1236 * length.
1237 */
1238 if (msg->flags & I2C_M_RECV_LEN) {
1239 if (end_state == MSG_END_CONTINUE) {
1240 i2c_dev->msg_len = 1;
1241 } else {
1242 i2c_dev->msg_buf += 1;
1243 i2c_dev->msg_len -= 1;
1244 }
1245 }
1246
1247 i2c_dev->msg_buf_remaining = i2c_dev->msg_len;
1248
1249 if (i2c_dev->msg_read)
1250 xfer_size = i2c_dev->msg_len;
1251 else
1252 xfer_size = i2c_dev->msg_len + I2C_PACKET_HEADER_SIZE;
1253
1254 xfer_size = ALIGN(xfer_size, BYTES_PER_FIFO_WORD);
1255
1256 i2c_dev->dma_mode = xfer_size > I2C_PIO_MODE_PREFERRED_LEN &&
1257 i2c_dev->dma_buf && !i2c_dev->atomic_mode;
1258
1259 tegra_i2c_config_fifo_trig(i2c_dev, xfer_size);
1260
1261 /*
1262 * Transfer time in mSec = Total bits / transfer rate
1263 * Total bits = 9 bits per byte (including ACK bit) + Start & stop bits
1264 */
1265 xfer_time += DIV_ROUND_CLOSEST(((xfer_size * 9) + 2) * MSEC_PER_SEC,
1266 i2c_dev->timings.bus_freq_hz);
1267
1268 int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
1269 tegra_i2c_unmask_irq(i2c_dev, int_mask);
1270
1271 if (i2c_dev->dma_mode) {
1272 if (i2c_dev->msg_read) {
1273 dma_sync_single_for_device(i2c_dev->dma_dev,
1274 i2c_dev->dma_phys,
1275 xfer_size, DMA_FROM_DEVICE);
1276
1277 err = tegra_i2c_dma_submit(i2c_dev, xfer_size);
1278 if (err)
1279 return err;
1280 } else {
1281 dma_sync_single_for_cpu(i2c_dev->dma_dev,
1282 i2c_dev->dma_phys,
1283 xfer_size, DMA_TO_DEVICE);
1284 }
1285 }
1286
1287 tegra_i2c_push_packet_header(i2c_dev, msg, end_state);
1288
1289 if (!i2c_dev->msg_read) {
1290 if (i2c_dev->dma_mode) {
1291 memcpy(i2c_dev->dma_buf + I2C_PACKET_HEADER_SIZE,
1292 msg->buf, i2c_dev->msg_len);
1293
1294 dma_sync_single_for_device(i2c_dev->dma_dev,
1295 i2c_dev->dma_phys,
1296 xfer_size, DMA_TO_DEVICE);
1297
1298 err = tegra_i2c_dma_submit(i2c_dev, xfer_size);
1299 if (err)
1300 return err;
1301 } else {
1302 tegra_i2c_fill_tx_fifo(i2c_dev);
1303 }
1304 }
1305
1306 if (i2c_dev->hw->has_per_pkt_xfer_complete_irq)
1307 int_mask |= I2C_INT_PACKET_XFER_COMPLETE;
1308
1309 if (!i2c_dev->dma_mode) {
1310 if (msg->flags & I2C_M_RD)
1311 int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
1312 else if (i2c_dev->msg_buf_remaining)
1313 int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
1314 }
1315
1316 tegra_i2c_unmask_irq(i2c_dev, int_mask);
1317 dev_dbg(i2c_dev->dev, "unmasked IRQ: %02x\n",
1318 i2c_readl(i2c_dev, I2C_INT_MASK));
1319
1320 if (i2c_dev->dma_mode) {
1321 time_left = tegra_i2c_wait_completion(i2c_dev,
1322 &i2c_dev->dma_complete,
1323 xfer_time);
1324
1325 /*
1326 * Synchronize DMA first, since dmaengine_terminate_sync()
1327 * performs synchronization after the transfer's termination
1328 * and we want to get a completion if transfer succeeded.
1329 */
1330 dmaengine_synchronize(i2c_dev->dma_chan);
1331 dmaengine_terminate_sync(i2c_dev->dma_chan);
1332
1333 if (!time_left && !completion_done(&i2c_dev->dma_complete)) {
1334 tegra_i2c_init(i2c_dev);
1335 return -ETIMEDOUT;
1336 }
1337
1338 if (i2c_dev->msg_read && i2c_dev->msg_err == I2C_ERR_NONE) {
1339 dma_sync_single_for_cpu(i2c_dev->dma_dev,
1340 i2c_dev->dma_phys,
1341 xfer_size, DMA_FROM_DEVICE);
1342
1343 memcpy(i2c_dev->msg_buf, i2c_dev->dma_buf, i2c_dev->msg_len);
1344 }
1345 }
1346
1347 time_left = tegra_i2c_wait_completion(i2c_dev, &i2c_dev->msg_complete,
1348 xfer_time);
1349
1350 tegra_i2c_mask_irq(i2c_dev, int_mask);
1351
1352 if (time_left == 0) {
1353 tegra_i2c_init(i2c_dev);
1354 return -ETIMEDOUT;
1355 }
1356
1357 dev_dbg(i2c_dev->dev, "transfer complete: %lu %d %d\n",
1358 time_left, completion_done(&i2c_dev->msg_complete),
1359 i2c_dev->msg_err);
1360
1361 i2c_dev->dma_mode = false;
1362
1363 err = tegra_i2c_error_recover(i2c_dev, msg);
1364 if (err)
1365 return err;
1366
1367 return 0;
1368 }
1369
tegra_i2c_xfer(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1370 static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
1371 int num)
1372 {
1373 struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1374 int i, ret;
1375
1376 ret = pm_runtime_get_sync(i2c_dev->dev);
1377 if (ret < 0) {
1378 dev_err(i2c_dev->dev, "runtime resume failed %d\n", ret);
1379 pm_runtime_put_noidle(i2c_dev->dev);
1380 return ret;
1381 }
1382
1383 for (i = 0; i < num; i++) {
1384 enum msg_end_type end_type = MSG_END_STOP;
1385
1386 if (i < (num - 1)) {
1387 /* check whether follow up message is coming */
1388 if (msgs[i + 1].flags & I2C_M_NOSTART)
1389 end_type = MSG_END_CONTINUE;
1390 else
1391 end_type = MSG_END_REPEAT_START;
1392 }
1393 /* If M_RECV_LEN use ContinueXfer to read the first byte */
1394 if (msgs[i].flags & I2C_M_RECV_LEN) {
1395 ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], MSG_END_CONTINUE);
1396 if (ret)
1397 break;
1398 /* Set the msg length from first byte */
1399 msgs[i].len += msgs[i].buf[0];
1400 dev_dbg(i2c_dev->dev, "reading %d bytes\n", msgs[i].len);
1401 }
1402 ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], end_type);
1403 if (ret)
1404 break;
1405 }
1406
1407 pm_runtime_put(i2c_dev->dev);
1408
1409 return ret ?: i;
1410 }
1411
tegra_i2c_xfer_atomic(struct i2c_adapter * adap,struct i2c_msg msgs[],int num)1412 static int tegra_i2c_xfer_atomic(struct i2c_adapter *adap,
1413 struct i2c_msg msgs[], int num)
1414 {
1415 struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1416 int ret;
1417
1418 i2c_dev->atomic_mode = true;
1419 ret = tegra_i2c_xfer(adap, msgs, num);
1420 i2c_dev->atomic_mode = false;
1421
1422 return ret;
1423 }
1424
tegra_i2c_func(struct i2c_adapter * adap)1425 static u32 tegra_i2c_func(struct i2c_adapter *adap)
1426 {
1427 struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
1428 u32 ret = I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
1429 I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING;
1430
1431 if (i2c_dev->hw->has_continue_xfer_support)
1432 ret |= I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_READ_BLOCK_DATA;
1433
1434 return ret;
1435 }
1436
1437 static const struct i2c_algorithm tegra_i2c_algo = {
1438 .master_xfer = tegra_i2c_xfer,
1439 .master_xfer_atomic = tegra_i2c_xfer_atomic,
1440 .functionality = tegra_i2c_func,
1441 };
1442
1443 /* payload size is only 12 bit */
1444 static const struct i2c_adapter_quirks tegra_i2c_quirks = {
1445 .flags = I2C_AQ_NO_ZERO_LEN,
1446 .max_read_len = SZ_4K,
1447 .max_write_len = SZ_4K - I2C_PACKET_HEADER_SIZE,
1448 };
1449
1450 static const struct i2c_adapter_quirks tegra194_i2c_quirks = {
1451 .flags = I2C_AQ_NO_ZERO_LEN,
1452 .max_write_len = SZ_64K - I2C_PACKET_HEADER_SIZE,
1453 };
1454
1455 static struct i2c_bus_recovery_info tegra_i2c_recovery_info = {
1456 .recover_bus = tegra_i2c_issue_bus_clear,
1457 };
1458
1459 static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
1460 .has_continue_xfer_support = false,
1461 .has_per_pkt_xfer_complete_irq = false,
1462 .clk_divisor_hs_mode = 3,
1463 .clk_divisor_std_mode = 0,
1464 .clk_divisor_fast_mode = 0,
1465 .clk_divisor_fast_plus_mode = 0,
1466 .has_config_load_reg = false,
1467 .has_multi_master_mode = false,
1468 .has_slcg_override_reg = false,
1469 .has_mst_fifo = false,
1470 .quirks = &tegra_i2c_quirks,
1471 .supports_bus_clear = false,
1472 .has_apb_dma = true,
1473 .tlow_std_mode = 0x4,
1474 .thigh_std_mode = 0x2,
1475 .tlow_fast_fastplus_mode = 0x4,
1476 .thigh_fast_fastplus_mode = 0x2,
1477 .setup_hold_time_std_mode = 0x0,
1478 .setup_hold_time_fast_fast_plus_mode = 0x0,
1479 .setup_hold_time_hs_mode = 0x0,
1480 .has_interface_timing_reg = false,
1481 };
1482
1483 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
1484 .has_continue_xfer_support = true,
1485 .has_per_pkt_xfer_complete_irq = false,
1486 .clk_divisor_hs_mode = 3,
1487 .clk_divisor_std_mode = 0,
1488 .clk_divisor_fast_mode = 0,
1489 .clk_divisor_fast_plus_mode = 0,
1490 .has_config_load_reg = false,
1491 .has_multi_master_mode = false,
1492 .has_slcg_override_reg = false,
1493 .has_mst_fifo = false,
1494 .quirks = &tegra_i2c_quirks,
1495 .supports_bus_clear = false,
1496 .has_apb_dma = true,
1497 .tlow_std_mode = 0x4,
1498 .thigh_std_mode = 0x2,
1499 .tlow_fast_fastplus_mode = 0x4,
1500 .thigh_fast_fastplus_mode = 0x2,
1501 .setup_hold_time_std_mode = 0x0,
1502 .setup_hold_time_fast_fast_plus_mode = 0x0,
1503 .setup_hold_time_hs_mode = 0x0,
1504 .has_interface_timing_reg = false,
1505 };
1506
1507 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
1508 .has_continue_xfer_support = true,
1509 .has_per_pkt_xfer_complete_irq = true,
1510 .clk_divisor_hs_mode = 1,
1511 .clk_divisor_std_mode = 0x19,
1512 .clk_divisor_fast_mode = 0x19,
1513 .clk_divisor_fast_plus_mode = 0x10,
1514 .has_config_load_reg = false,
1515 .has_multi_master_mode = false,
1516 .has_slcg_override_reg = false,
1517 .has_mst_fifo = false,
1518 .quirks = &tegra_i2c_quirks,
1519 .supports_bus_clear = true,
1520 .has_apb_dma = true,
1521 .tlow_std_mode = 0x4,
1522 .thigh_std_mode = 0x2,
1523 .tlow_fast_fastplus_mode = 0x4,
1524 .thigh_fast_fastplus_mode = 0x2,
1525 .setup_hold_time_std_mode = 0x0,
1526 .setup_hold_time_fast_fast_plus_mode = 0x0,
1527 .setup_hold_time_hs_mode = 0x0,
1528 .has_interface_timing_reg = false,
1529 };
1530
1531 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
1532 .has_continue_xfer_support = true,
1533 .has_per_pkt_xfer_complete_irq = true,
1534 .clk_divisor_hs_mode = 1,
1535 .clk_divisor_std_mode = 0x19,
1536 .clk_divisor_fast_mode = 0x19,
1537 .clk_divisor_fast_plus_mode = 0x10,
1538 .has_config_load_reg = true,
1539 .has_multi_master_mode = false,
1540 .has_slcg_override_reg = true,
1541 .has_mst_fifo = false,
1542 .quirks = &tegra_i2c_quirks,
1543 .supports_bus_clear = true,
1544 .has_apb_dma = true,
1545 .tlow_std_mode = 0x4,
1546 .thigh_std_mode = 0x2,
1547 .tlow_fast_fastplus_mode = 0x4,
1548 .thigh_fast_fastplus_mode = 0x2,
1549 .setup_hold_time_std_mode = 0x0,
1550 .setup_hold_time_fast_fast_plus_mode = 0x0,
1551 .setup_hold_time_hs_mode = 0x0,
1552 .has_interface_timing_reg = true,
1553 };
1554
1555 static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
1556 .has_continue_xfer_support = true,
1557 .has_per_pkt_xfer_complete_irq = true,
1558 .clk_divisor_hs_mode = 1,
1559 .clk_divisor_std_mode = 0x19,
1560 .clk_divisor_fast_mode = 0x19,
1561 .clk_divisor_fast_plus_mode = 0x10,
1562 .has_config_load_reg = true,
1563 .has_multi_master_mode = false,
1564 .has_slcg_override_reg = true,
1565 .has_mst_fifo = false,
1566 .quirks = &tegra_i2c_quirks,
1567 .supports_bus_clear = true,
1568 .has_apb_dma = true,
1569 .tlow_std_mode = 0x4,
1570 .thigh_std_mode = 0x2,
1571 .tlow_fast_fastplus_mode = 0x4,
1572 .thigh_fast_fastplus_mode = 0x2,
1573 .setup_hold_time_std_mode = 0,
1574 .setup_hold_time_fast_fast_plus_mode = 0,
1575 .setup_hold_time_hs_mode = 0,
1576 .has_interface_timing_reg = true,
1577 };
1578
1579 static const struct tegra_i2c_hw_feature tegra186_i2c_hw = {
1580 .has_continue_xfer_support = true,
1581 .has_per_pkt_xfer_complete_irq = true,
1582 .clk_divisor_hs_mode = 1,
1583 .clk_divisor_std_mode = 0x16,
1584 .clk_divisor_fast_mode = 0x19,
1585 .clk_divisor_fast_plus_mode = 0x10,
1586 .has_config_load_reg = true,
1587 .has_multi_master_mode = false,
1588 .has_slcg_override_reg = true,
1589 .has_mst_fifo = false,
1590 .quirks = &tegra_i2c_quirks,
1591 .supports_bus_clear = true,
1592 .has_apb_dma = false,
1593 .tlow_std_mode = 0x4,
1594 .thigh_std_mode = 0x3,
1595 .tlow_fast_fastplus_mode = 0x4,
1596 .thigh_fast_fastplus_mode = 0x2,
1597 .setup_hold_time_std_mode = 0,
1598 .setup_hold_time_fast_fast_plus_mode = 0,
1599 .setup_hold_time_hs_mode = 0,
1600 .has_interface_timing_reg = true,
1601 };
1602
1603 static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
1604 .has_continue_xfer_support = true,
1605 .has_per_pkt_xfer_complete_irq = true,
1606 .clk_divisor_hs_mode = 1,
1607 .clk_divisor_std_mode = 0x4f,
1608 .clk_divisor_fast_mode = 0x3c,
1609 .clk_divisor_fast_plus_mode = 0x16,
1610 .has_config_load_reg = true,
1611 .has_multi_master_mode = true,
1612 .has_slcg_override_reg = true,
1613 .has_mst_fifo = true,
1614 .quirks = &tegra194_i2c_quirks,
1615 .supports_bus_clear = true,
1616 .has_apb_dma = false,
1617 .tlow_std_mode = 0x8,
1618 .thigh_std_mode = 0x7,
1619 .tlow_fast_fastplus_mode = 0x2,
1620 .thigh_fast_fastplus_mode = 0x2,
1621 .setup_hold_time_std_mode = 0x08080808,
1622 .setup_hold_time_fast_fast_plus_mode = 0x02020202,
1623 .setup_hold_time_hs_mode = 0x090909,
1624 .has_interface_timing_reg = true,
1625 };
1626
1627 static const struct of_device_id tegra_i2c_of_match[] = {
1628 { .compatible = "nvidia,tegra194-i2c", .data = &tegra194_i2c_hw, },
1629 { .compatible = "nvidia,tegra186-i2c", .data = &tegra186_i2c_hw, },
1630 #if IS_ENABLED(CONFIG_ARCH_TEGRA_210_SOC)
1631 { .compatible = "nvidia,tegra210-i2c-vi", .data = &tegra210_i2c_hw, },
1632 #endif
1633 { .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
1634 { .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
1635 { .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
1636 { .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
1637 { .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
1638 #if IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC)
1639 { .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
1640 #endif
1641 {},
1642 };
1643 MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
1644
tegra_i2c_parse_dt(struct tegra_i2c_dev * i2c_dev)1645 static void tegra_i2c_parse_dt(struct tegra_i2c_dev *i2c_dev)
1646 {
1647 struct device_node *np = i2c_dev->dev->of_node;
1648 bool multi_mode;
1649
1650 i2c_parse_fw_timings(i2c_dev->dev, &i2c_dev->timings, true);
1651
1652 multi_mode = device_property_read_bool(i2c_dev->dev, "multi-master");
1653 i2c_dev->multimaster_mode = multi_mode;
1654
1655 if (IS_ENABLED(CONFIG_ARCH_TEGRA_2x_SOC) &&
1656 of_device_is_compatible(np, "nvidia,tegra20-i2c-dvc"))
1657 i2c_dev->is_dvc = true;
1658
1659 if (IS_ENABLED(CONFIG_ARCH_TEGRA_210_SOC) &&
1660 of_device_is_compatible(np, "nvidia,tegra210-i2c-vi"))
1661 i2c_dev->is_vi = true;
1662 }
1663
tegra_i2c_init_reset(struct tegra_i2c_dev * i2c_dev)1664 static int tegra_i2c_init_reset(struct tegra_i2c_dev *i2c_dev)
1665 {
1666 if (ACPI_HANDLE(i2c_dev->dev))
1667 return 0;
1668
1669 i2c_dev->rst = devm_reset_control_get_exclusive(i2c_dev->dev, "i2c");
1670 if (IS_ERR(i2c_dev->rst))
1671 return dev_err_probe(i2c_dev->dev, PTR_ERR(i2c_dev->rst),
1672 "failed to get reset control\n");
1673
1674 return 0;
1675 }
1676
tegra_i2c_init_clocks(struct tegra_i2c_dev * i2c_dev)1677 static int tegra_i2c_init_clocks(struct tegra_i2c_dev *i2c_dev)
1678 {
1679 int err;
1680
1681 if (ACPI_HANDLE(i2c_dev->dev))
1682 return 0;
1683
1684 i2c_dev->clocks[i2c_dev->nclocks++].id = "div-clk";
1685
1686 if (i2c_dev->hw == &tegra20_i2c_hw || i2c_dev->hw == &tegra30_i2c_hw)
1687 i2c_dev->clocks[i2c_dev->nclocks++].id = "fast-clk";
1688
1689 if (IS_VI(i2c_dev))
1690 i2c_dev->clocks[i2c_dev->nclocks++].id = "slow";
1691
1692 err = devm_clk_bulk_get(i2c_dev->dev, i2c_dev->nclocks,
1693 i2c_dev->clocks);
1694 if (err)
1695 return err;
1696
1697 err = clk_bulk_prepare(i2c_dev->nclocks, i2c_dev->clocks);
1698 if (err)
1699 return err;
1700
1701 i2c_dev->div_clk = i2c_dev->clocks[0].clk;
1702
1703 if (!i2c_dev->multimaster_mode)
1704 return 0;
1705
1706 err = clk_enable(i2c_dev->div_clk);
1707 if (err) {
1708 dev_err(i2c_dev->dev, "failed to enable div-clk: %d\n", err);
1709 goto unprepare_clocks;
1710 }
1711
1712 return 0;
1713
1714 unprepare_clocks:
1715 clk_bulk_unprepare(i2c_dev->nclocks, i2c_dev->clocks);
1716
1717 return err;
1718 }
1719
tegra_i2c_release_clocks(struct tegra_i2c_dev * i2c_dev)1720 static void tegra_i2c_release_clocks(struct tegra_i2c_dev *i2c_dev)
1721 {
1722 if (i2c_dev->multimaster_mode)
1723 clk_disable(i2c_dev->div_clk);
1724
1725 clk_bulk_unprepare(i2c_dev->nclocks, i2c_dev->clocks);
1726 }
1727
tegra_i2c_init_hardware(struct tegra_i2c_dev * i2c_dev)1728 static int tegra_i2c_init_hardware(struct tegra_i2c_dev *i2c_dev)
1729 {
1730 int ret;
1731
1732 ret = pm_runtime_get_sync(i2c_dev->dev);
1733 if (ret < 0)
1734 dev_err(i2c_dev->dev, "runtime resume failed: %d\n", ret);
1735 else
1736 ret = tegra_i2c_init(i2c_dev);
1737
1738 pm_runtime_put_sync(i2c_dev->dev);
1739
1740 return ret;
1741 }
1742
tegra_i2c_probe(struct platform_device * pdev)1743 static int tegra_i2c_probe(struct platform_device *pdev)
1744 {
1745 struct tegra_i2c_dev *i2c_dev;
1746 struct resource *res;
1747 int err;
1748
1749 i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
1750 if (!i2c_dev)
1751 return -ENOMEM;
1752
1753 platform_set_drvdata(pdev, i2c_dev);
1754
1755 init_completion(&i2c_dev->msg_complete);
1756 init_completion(&i2c_dev->dma_complete);
1757
1758 i2c_dev->hw = device_get_match_data(&pdev->dev);
1759 i2c_dev->cont_id = pdev->id;
1760 i2c_dev->dev = &pdev->dev;
1761
1762 i2c_dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
1763 if (IS_ERR(i2c_dev->base))
1764 return PTR_ERR(i2c_dev->base);
1765
1766 i2c_dev->base_phys = res->start;
1767
1768 err = platform_get_irq(pdev, 0);
1769 if (err < 0)
1770 return err;
1771
1772 i2c_dev->irq = err;
1773
1774 /* interrupt will be enabled during of transfer time */
1775 irq_set_status_flags(i2c_dev->irq, IRQ_NOAUTOEN);
1776
1777 err = devm_request_threaded_irq(i2c_dev->dev, i2c_dev->irq,
1778 NULL, tegra_i2c_isr,
1779 IRQF_NO_SUSPEND | IRQF_ONESHOT,
1780 dev_name(i2c_dev->dev), i2c_dev);
1781 if (err)
1782 return err;
1783
1784 tegra_i2c_parse_dt(i2c_dev);
1785
1786 err = tegra_i2c_init_reset(i2c_dev);
1787 if (err)
1788 return err;
1789
1790 err = tegra_i2c_init_clocks(i2c_dev);
1791 if (err)
1792 return err;
1793
1794 err = tegra_i2c_init_dma(i2c_dev);
1795 if (err)
1796 goto release_clocks;
1797
1798 /*
1799 * VI I2C is in VE power domain which is not always ON and not
1800 * IRQ-safe. Thus, IRQ-safe device shouldn't be attached to a
1801 * non IRQ-safe domain because this prevents powering off the power
1802 * domain.
1803 *
1804 * VI I2C device shouldn't be marked as IRQ-safe because VI I2C won't
1805 * be used for atomic transfers. ACPI device is not IRQ safe also.
1806 */
1807 if (!IS_VI(i2c_dev) && !has_acpi_companion(i2c_dev->dev))
1808 pm_runtime_irq_safe(i2c_dev->dev);
1809
1810 pm_runtime_enable(i2c_dev->dev);
1811
1812 err = tegra_i2c_init_hardware(i2c_dev);
1813 if (err)
1814 goto release_rpm;
1815
1816 i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
1817 i2c_dev->adapter.dev.of_node = i2c_dev->dev->of_node;
1818 i2c_dev->adapter.dev.parent = i2c_dev->dev;
1819 i2c_dev->adapter.retries = 1;
1820 i2c_dev->adapter.timeout = 6 * HZ;
1821 i2c_dev->adapter.quirks = i2c_dev->hw->quirks;
1822 i2c_dev->adapter.owner = THIS_MODULE;
1823 i2c_dev->adapter.class = I2C_CLASS_DEPRECATED;
1824 i2c_dev->adapter.algo = &tegra_i2c_algo;
1825 i2c_dev->adapter.nr = pdev->id;
1826 ACPI_COMPANION_SET(&i2c_dev->adapter.dev, ACPI_COMPANION(&pdev->dev));
1827
1828 if (i2c_dev->hw->supports_bus_clear)
1829 i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info;
1830
1831 strscpy(i2c_dev->adapter.name, dev_name(i2c_dev->dev),
1832 sizeof(i2c_dev->adapter.name));
1833
1834 err = i2c_add_numbered_adapter(&i2c_dev->adapter);
1835 if (err)
1836 goto release_rpm;
1837
1838 return 0;
1839
1840 release_rpm:
1841 pm_runtime_disable(i2c_dev->dev);
1842
1843 tegra_i2c_release_dma(i2c_dev);
1844 release_clocks:
1845 tegra_i2c_release_clocks(i2c_dev);
1846
1847 return err;
1848 }
1849
tegra_i2c_remove(struct platform_device * pdev)1850 static void tegra_i2c_remove(struct platform_device *pdev)
1851 {
1852 struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
1853
1854 i2c_del_adapter(&i2c_dev->adapter);
1855 pm_runtime_force_suspend(i2c_dev->dev);
1856
1857 tegra_i2c_release_dma(i2c_dev);
1858 tegra_i2c_release_clocks(i2c_dev);
1859 }
1860
tegra_i2c_runtime_resume(struct device * dev)1861 static int __maybe_unused tegra_i2c_runtime_resume(struct device *dev)
1862 {
1863 struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1864 int err;
1865
1866 err = pinctrl_pm_select_default_state(dev);
1867 if (err)
1868 return err;
1869
1870 err = clk_bulk_enable(i2c_dev->nclocks, i2c_dev->clocks);
1871 if (err)
1872 return err;
1873
1874 /*
1875 * VI I2C device is attached to VE power domain which goes through
1876 * power ON/OFF during runtime PM resume/suspend, meaning that
1877 * controller needs to be re-initialized after power ON.
1878 */
1879 if (IS_VI(i2c_dev)) {
1880 err = tegra_i2c_init(i2c_dev);
1881 if (err)
1882 goto disable_clocks;
1883 }
1884
1885 return 0;
1886
1887 disable_clocks:
1888 clk_bulk_disable(i2c_dev->nclocks, i2c_dev->clocks);
1889
1890 return err;
1891 }
1892
tegra_i2c_runtime_suspend(struct device * dev)1893 static int __maybe_unused tegra_i2c_runtime_suspend(struct device *dev)
1894 {
1895 struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1896
1897 clk_bulk_disable(i2c_dev->nclocks, i2c_dev->clocks);
1898
1899 return pinctrl_pm_select_idle_state(dev);
1900 }
1901
tegra_i2c_suspend(struct device * dev)1902 static int __maybe_unused tegra_i2c_suspend(struct device *dev)
1903 {
1904 struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1905 int err;
1906
1907 i2c_mark_adapter_suspended(&i2c_dev->adapter);
1908
1909 if (!pm_runtime_status_suspended(dev)) {
1910 err = tegra_i2c_runtime_suspend(dev);
1911 if (err)
1912 return err;
1913 }
1914
1915 return 0;
1916 }
1917
tegra_i2c_resume(struct device * dev)1918 static int __maybe_unused tegra_i2c_resume(struct device *dev)
1919 {
1920 struct tegra_i2c_dev *i2c_dev = dev_get_drvdata(dev);
1921 int err;
1922
1923 /*
1924 * We need to ensure that clocks are enabled so that registers can be
1925 * restored in tegra_i2c_init().
1926 */
1927 err = tegra_i2c_runtime_resume(dev);
1928 if (err)
1929 return err;
1930
1931 err = tegra_i2c_init(i2c_dev);
1932 if (err)
1933 return err;
1934
1935 /*
1936 * In case we are runtime suspended, disable clocks again so that we
1937 * don't unbalance the clock reference counts during the next runtime
1938 * resume transition.
1939 */
1940 if (pm_runtime_status_suspended(dev)) {
1941 err = tegra_i2c_runtime_suspend(dev);
1942 if (err)
1943 return err;
1944 }
1945
1946 i2c_mark_adapter_resumed(&i2c_dev->adapter);
1947
1948 return 0;
1949 }
1950
1951 static const struct dev_pm_ops tegra_i2c_pm = {
1952 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume)
1953 SET_RUNTIME_PM_OPS(tegra_i2c_runtime_suspend, tegra_i2c_runtime_resume,
1954 NULL)
1955 };
1956
1957 static const struct acpi_device_id tegra_i2c_acpi_match[] = {
1958 {.id = "NVDA0101", .driver_data = (kernel_ulong_t)&tegra210_i2c_hw},
1959 {.id = "NVDA0201", .driver_data = (kernel_ulong_t)&tegra186_i2c_hw},
1960 {.id = "NVDA0301", .driver_data = (kernel_ulong_t)&tegra194_i2c_hw},
1961 { }
1962 };
1963 MODULE_DEVICE_TABLE(acpi, tegra_i2c_acpi_match);
1964
1965 static struct platform_driver tegra_i2c_driver = {
1966 .probe = tegra_i2c_probe,
1967 .remove_new = tegra_i2c_remove,
1968 .driver = {
1969 .name = "tegra-i2c",
1970 .of_match_table = tegra_i2c_of_match,
1971 .acpi_match_table = tegra_i2c_acpi_match,
1972 .pm = &tegra_i2c_pm,
1973 },
1974 };
1975 module_platform_driver(tegra_i2c_driver);
1976
1977 MODULE_DESCRIPTION("NVIDIA Tegra I2C Bus Controller driver");
1978 MODULE_AUTHOR("Colin Cross");
1979 MODULE_LICENSE("GPL v2");
1980