1 // SPDX-License-Identifier: GPL-2.0-only
3  * ST SPEAr ADC driver
17 #include <linux/clk.h>
40 #define SPEAR_ADC_MOD_NAME "spear-adc"
51 	u32 clk;	/* Not avail for 1340 & 1310 */  member
64 	u32 clk;  member
76 	struct clk *clk;  member
95  * Functions to access some SPEAr ADC register. Abstracted into
101 	__raw_writel(val, &st->adc_base_spear6xx->status);  in spear_adc_set_status()
107 	u32 apb_clk = clk_get_rate(st->clk);  in spear_adc_set_clk()
111 	clk_high = count - clk_low;  in spear_adc_set_clk()
112 	st->current_clk = apb_clk / count;  in spear_adc_set_clk()
115 		     &st->adc_base_spear6xx->clk);  in spear_adc_set_clk()
121 	__raw_writel(val, &st->adc_base_spear6xx->ch_ctrl[n]);  in spear_adc_set_ctrl()
126 	if (device_is_compatible(st->dev, "st,spear600-adc")) {  in spear_adc_get_average()
127 		return __raw_readl(&st->adc_base_spear6xx->average.msb) &  in spear_adc_get_average()
130 		return __raw_readl(&st->adc_base_spear3xx->average) &  in spear_adc_get_average()
137 	if (device_is_compatible(st->dev, "st,spear600-adc")) {  in spear_adc_set_scanrate()
139 			     &st->adc_base_spear6xx->scan_rate_lo);  in spear_adc_set_scanrate()
141 			     &st->adc_base_spear6xx->scan_rate_hi);  in spear_adc_set_scanrate()
143 		__raw_writel(rate, &st->adc_base_spear3xx->scan_rate);  in spear_adc_set_scanrate()
158 		mutex_lock(&st->lock);  in spear_adc_read_raw()
160 		status = SPEAR_ADC_STATUS_CHANNEL_NUM(chan->channel) |  in spear_adc_read_raw()
161 			SPEAR_ADC_STATUS_AVG_SAMPLE(st->avg_samples) |  in spear_adc_read_raw()
164 		if (st->vref_external == 0)  in spear_adc_read_raw()
168 		wait_for_completion(&st->completion); /* set by ISR */  in spear_adc_read_raw()
169 		*val = st->value;  in spear_adc_read_raw()
171 		mutex_unlock(&st->lock);  in spear_adc_read_raw()
176 		*val = st->vref_external;  in spear_adc_read_raw()
180 		*val = st->current_clk;  in spear_adc_read_raw()
184 	return -EINVAL;  in spear_adc_read_raw()
197 		return -EINVAL;  in spear_adc_write_raw()
199 	mutex_lock(&st->lock);  in spear_adc_write_raw()
204 		ret = -EINVAL;  in spear_adc_write_raw()
211 	mutex_unlock(&st->lock);  in spear_adc_write_raw()
240 	st->value = spear_adc_get_average(st);  in spear_adc_isr()
241 	complete(&st->completion);  in spear_adc_isr()
250 	/* Reset ADC core */  in spear_adc_configure()
252 	__raw_writel(0, &st->adc_base_spear6xx->clk);  in spear_adc_configure()
257 	spear_adc_set_clk(st, st->sampling_freq);  in spear_adc_configure()
269 	struct device *dev = &pdev->dev;  in spear_adc_probe()
272 	int ret = -ENODEV;  in spear_adc_probe()
277 		return dev_err_probe(dev, -ENOMEM,  in spear_adc_probe()
281 	st->dev = dev;  in spear_adc_probe()
283 	mutex_init(&st->lock);  in spear_adc_probe()
288 	 * to support multi-arch kernels.  in spear_adc_probe()
290 	st->adc_base_spear6xx = devm_platform_ioremap_resource(pdev, 0);  in spear_adc_probe()
291 	if (IS_ERR(st->adc_base_spear6xx))  in spear_adc_probe()
292 		return PTR_ERR(st->adc_base_spear6xx);  in spear_adc_probe()
294 	st->adc_base_spear3xx =  in spear_adc_probe()
295 		(struct adc_regs_spear3xx __iomem *)st->adc_base_spear6xx;  in spear_adc_probe()
297 	st->clk = devm_clk_get_enabled(dev, NULL);  in spear_adc_probe()
298 	if (IS_ERR(st->clk))  in spear_adc_probe()
299 		return dev_err_probe(dev, PTR_ERR(st->clk),  in spear_adc_probe()
311 	if (device_property_read_u32(dev, "sampling-frequency", &st->sampling_freq))  in spear_adc_probe()
312 		return dev_err_probe(dev, -EINVAL,  in spear_adc_probe()
313 				     "sampling-frequency missing in DT\n");  in spear_adc_probe()
319 	device_property_read_u32(dev, "average-samples", &st->avg_samples);  in spear_adc_probe()
325 	device_property_read_u32(dev, "vref-external", &st->vref_external);  in spear_adc_probe()
329 	init_completion(&st->completion);  in spear_adc_probe()
331 	indio_dev->name = SPEAR_ADC_MOD_NAME;  in spear_adc_probe()
332 	indio_dev->info = &spear_adc_info;  in spear_adc_probe()
333 	indio_dev->modes = INDIO_DIRECT_MODE;  in spear_adc_probe()
334 	indio_dev->channels = spear_adc_iio_channels;  in spear_adc_probe()
335 	indio_dev->num_channels = ARRAY_SIZE(spear_adc_iio_channels);  in spear_adc_probe()
341 	dev_info(dev, "SPEAR ADC driver loaded, IRQ %d\n", irq);  in spear_adc_probe()
347 	{ .compatible = "st,spear600-adc", },
363 MODULE_DESCRIPTION("SPEAr ADC driver");