1 // SPDX-License-Identifier: GPL-2.0-only
5  *  Derived from cx18-i2c.c
7  *  Copyright 2012-2015 Cisco Systems, Inc. and/or its affiliates.
11 #include "cobalt-driver.h"
12 #include "cobalt-i2c.h"
15 	/* Clock prescaler register lo-byte */
18 	/* Clock prescaler register high-byte */
32 /* CTR[7:0] - Control register */
40 /* CR[7:0] - Command register */
45 /* I2C stop condition */
54 /* I2C ack */
57 /* I2C Interrupt ack */
60 /* SR[7:0] - Status register */
65 /* Busy, I2C bus busy (as defined by start / stop bits) */
68 /* Arbitration lost - core lost arbitration */
88 			(cobalt->bar1 + COBALT_I2C_0_BASE);  in cobalt_i2c_regs()
91 			(cobalt->bar1 + COBALT_I2C_1_BASE);  in cobalt_i2c_regs()
94 			(cobalt->bar1 + COBALT_I2C_2_BASE);  in cobalt_i2c_regs()
97 			(cobalt->bar1 + COBALT_I2C_3_BASE);  in cobalt_i2c_regs()
100 			(cobalt->bar1 + COBALT_I2C_HSMA_BASE);  in cobalt_i2c_regs()
104 /* Do low-level i2c byte transfer.
105  * Returns -1 in case of an error or 0 otherwise.
108 		struct i2c_adapter *adap, bool start, bool stop,  in cobalt_tx_bytes()  argument
118 		iowrite8(data[i], &regs->txr_rxr);  in cobalt_tx_bytes()
125 		} else if (i == len - 1 && stop) {  in cobalt_tx_bytes()
126 			/* Write + Stop */  in cobalt_tx_bytes()
135 		iowrite8(cmd, &regs->cr_sr);  in cobalt_tx_bytes()
139 		status = ioread8(&regs->cr_sr);  in cobalt_tx_bytes()
141 			if (time_after(jiffies, start_time + adap->timeout))  in cobalt_tx_bytes()
142 				return -ETIMEDOUT;  in cobalt_tx_bytes()
144 			status = ioread8(&regs->cr_sr);  in cobalt_tx_bytes()
147 		/* Verify ACK */  in cobalt_tx_bytes()
149 			/* NO ACK! */  in cobalt_tx_bytes()
150 			return -EIO;  in cobalt_tx_bytes()
156 			return -EIO;  in cobalt_tx_bytes()
162 /* Do low-level i2c byte read.
163  * Returns -1 in case of an error or 0 otherwise.
166 		struct i2c_adapter *adap, bool start, bool stop,  in cobalt_rx_bytes()  argument
180 		} else if (i == len - 1 && stop) {  in cobalt_rx_bytes()
181 			/* Read + Stop */  in cobalt_rx_bytes()
189 		/* Last byte to read, no ACK */  in cobalt_rx_bytes()
190 		if (i == len - 1)  in cobalt_rx_bytes()
194 		iowrite8(cmd, &regs->cr_sr);  in cobalt_rx_bytes()
198 		status = ioread8(&regs->cr_sr);  in cobalt_rx_bytes()
200 			if (time_after(jiffies, start_time + adap->timeout))  in cobalt_rx_bytes()
201 				return -ETIMEDOUT;  in cobalt_rx_bytes()
203 			status = ioread8(&regs->cr_sr);  in cobalt_rx_bytes()
209 			return -EIO;  in cobalt_rx_bytes()
213 		data[i] = ioread8(&regs->txr_rxr);  in cobalt_rx_bytes()
218 /* Generate stop condition on i2c bus.
219  * The m00018 stop isn't doing the right thing (wrong timing).
220  * So instead send a start condition, 8 zeroes and a stop condition.
233 	struct cobalt_i2c_data *data = adap->algo_data;  in cobalt_xfer()
234 	struct cobalt_i2c_regs __iomem *regs = data->regs;  in cobalt_xfer()
241 		int stop = (i == num - 1);  in cobalt_xfer()  local
244 		flags = pmsg->flags;  in cobalt_xfer()
246 		if (!(pmsg->flags & I2C_M_NOSTART)) {  in cobalt_xfer()
247 			u8 addr = pmsg->addr << 1;  in cobalt_xfer()
253 			for (j = 0; j < adap->retries; j++) {  in cobalt_xfer()
264 		if (pmsg->flags & I2C_M_RD) {  in cobalt_xfer()
266 			ret = cobalt_rx_bytes(regs, adap, false, stop,  in cobalt_xfer()
267 					pmsg->buf, pmsg->len);  in cobalt_xfer()
272 			ret = cobalt_tx_bytes(regs, adap, false, stop,  in cobalt_xfer()
273 					pmsg->buf, pmsg->len);  in cobalt_xfer()
291 /* template for i2c-bit-algo */
294 	.algo = NULL,                   /* set by i2c-algo-bit */
304 /* init + register i2c algo-bit adapter */
315 	prescale = ((ALT_CPU_FREQ) / (5 * I2C_FREQUENCY)) - 1;  in cobalt_i2c_init()
320 		struct i2c_adapter *adap = &cobalt->i2c_adap[i];  in cobalt_i2c_init()
323 		iowrite8(M00018_CTR_BITMAP_EN_MSK, &regs->cr_sr);  in cobalt_i2c_init()
324 		iowrite8(0, &regs->ctr);  in cobalt_i2c_init()
325 		iowrite8(0, &regs->cr_sr);  in cobalt_i2c_init()
331 					adap->dev.parent = NULL;  in cobalt_i2c_init()
334 				return -ETIMEDOUT;  in cobalt_i2c_init()
336 			status = ioread8(&regs->cr_sr);  in cobalt_i2c_init()
340 		iowrite8(0, &regs->ctr);  in cobalt_i2c_init()
341 		iowrite8(0, &regs->cr_sr);  in cobalt_i2c_init()
344 		iowrite8(prescale & 0xff, &regs->prerlo);  in cobalt_i2c_init()
345 		iowrite8((prescale >> 8) & 0xff, &regs->prerhi);  in cobalt_i2c_init()
347 		iowrite8(M00018_CTR_BITMAP_EN_MSK, &regs->ctr);  in cobalt_i2c_init()
349 		cobalt->i2c_data[i].cobalt = cobalt;  in cobalt_i2c_init()
350 		cobalt->i2c_data[i].regs = regs;  in cobalt_i2c_init()
352 		adap->algo = &cobalt_algo;  in cobalt_i2c_init()
353 		adap->algo_data = &cobalt->i2c_data[i];  in cobalt_i2c_init()
354 		adap->retries = 3;  in cobalt_i2c_init()
355 		sprintf(adap->name + strlen(adap->name),  in cobalt_i2c_init()
356 				" #%d-%d", cobalt->instance, i);  in cobalt_i2c_init()
357 		i2c_set_adapdata(adap, &cobalt->v4l2_dev);  in cobalt_i2c_init()
358 		adap->dev.parent = &cobalt->pci_dev->dev;  in cobalt_i2c_init()
362 				adap->dev.parent = NULL;  in cobalt_i2c_init()
365 			while (i--)  in cobalt_i2c_init()
366 				i2c_del_adapter(&cobalt->i2c_adap[i]);  in cobalt_i2c_init()
369 		cobalt_info("registered bus %s\n", adap->name);  in cobalt_i2c_init()
381 		cobalt_err("unregistered bus %s\n", cobalt->i2c_adap[i].name);  in cobalt_i2c_exit()
382 		i2c_del_adapter(&cobalt->i2c_adap[i]);  in cobalt_i2c_exit()