1 // SPDX-License-Identifier: GPL-2.0-only
3  * ST SPEAr ADC driver
15 #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
86  * Functions to access some SPEAr ADC register. Abstracted into
92 	__raw_writel(val, &st->adc_base_spear6xx->status);  in spear_adc_set_status()
98 	u32 apb_clk = clk_get_rate(st->clk);  in spear_adc_set_clk()
102 	clk_high = count - clk_low;  in spear_adc_set_clk()
103 	st->current_clk = apb_clk / count;  in spear_adc_set_clk()
106 		     &st->adc_base_spear6xx->clk);  in spear_adc_set_clk()
112 	__raw_writel(val, &st->adc_base_spear6xx->ch_ctrl[n]);  in spear_adc_set_ctrl()
117 	if (of_device_is_compatible(st->np, "st,spear600-adc")) {  in spear_adc_get_average()
118 		return __raw_readl(&st->adc_base_spear6xx->average.msb) &  in spear_adc_get_average()
121 		return __raw_readl(&st->adc_base_spear3xx->average) &  in spear_adc_get_average()
128 	if (of_device_is_compatible(st->np, "st,spear600-adc")) {  in spear_adc_set_scanrate()
130 			     &st->adc_base_spear6xx->scan_rate_lo);  in spear_adc_set_scanrate()
132 			     &st->adc_base_spear6xx->scan_rate_hi);  in spear_adc_set_scanrate()
134 		__raw_writel(rate, &st->adc_base_spear3xx->scan_rate);  in spear_adc_set_scanrate()
149 		mutex_lock(&indio_dev->mlock);  in spear_adc_read_raw()
151 		status = SPEAR_ADC_STATUS_CHANNEL_NUM(chan->channel) |  in spear_adc_read_raw()
152 			SPEAR_ADC_STATUS_AVG_SAMPLE(st->avg_samples) |  in spear_adc_read_raw()
155 		if (st->vref_external == 0)  in spear_adc_read_raw()
159 		wait_for_completion(&st->completion); /* set by ISR */  in spear_adc_read_raw()
160 		*val = st->value;  in spear_adc_read_raw()
162 		mutex_unlock(&indio_dev->mlock);  in spear_adc_read_raw()
167 		*val = st->vref_external;  in spear_adc_read_raw()
171 		*val = st->current_clk;  in spear_adc_read_raw()
175 	return -EINVAL;  in spear_adc_read_raw()
188 		return -EINVAL;  in spear_adc_write_raw()
190 	mutex_lock(&indio_dev->mlock);  in spear_adc_write_raw()
195 		ret = -EINVAL;  in spear_adc_write_raw()
202 	mutex_unlock(&indio_dev->mlock);  in spear_adc_write_raw()
231 	st->value = spear_adc_get_average(st);  in spear_adc_isr()
232 	complete(&st->completion);  in spear_adc_isr()
241 	/* Reset ADC core */  in spear_adc_configure()
243 	__raw_writel(0, &st->adc_base_spear6xx->clk);  in spear_adc_configure()
248 	spear_adc_set_clk(st, st->sampling_freq);  in spear_adc_configure()
260 	struct device_node *np = pdev->dev.of_node;  in spear_adc_probe()
261 	struct device *dev = &pdev->dev;  in spear_adc_probe()
264 	int ret = -ENODEV;  in spear_adc_probe()
270 		return -ENOMEM;  in spear_adc_probe()
274 	st->np = np;  in spear_adc_probe()
279 	 * to support multi-arch kernels.  in spear_adc_probe()
281 	st->adc_base_spear6xx = devm_platform_ioremap_resource(pdev, 0);  in spear_adc_probe()
282 	if (IS_ERR(st->adc_base_spear6xx))  in spear_adc_probe()
283 		return PTR_ERR(st->adc_base_spear6xx);  in spear_adc_probe()
285 	st->adc_base_spear3xx =  in spear_adc_probe()
286 		(struct adc_regs_spear3xx __iomem *)st->adc_base_spear6xx;  in spear_adc_probe()
288 	st->clk = devm_clk_get(dev, NULL);  in spear_adc_probe()
289 	if (IS_ERR(st->clk)) {  in spear_adc_probe()
291 		return PTR_ERR(st->clk);  in spear_adc_probe()
294 	ret = clk_prepare_enable(st->clk);  in spear_adc_probe()
302 		ret = -EINVAL;  in spear_adc_probe()
313 	if (of_property_read_u32(np, "sampling-frequency",  in spear_adc_probe()
314 				 &st->sampling_freq)) {  in spear_adc_probe()
315 		dev_err(dev, "sampling-frequency missing in DT\n");  in spear_adc_probe()
316 		ret = -EINVAL;  in spear_adc_probe()
324 	of_property_read_u32(np, "average-samples", &st->avg_samples);  in spear_adc_probe()
330 	of_property_read_u32(np, "vref-external", &st->vref_external);  in spear_adc_probe()
336 	init_completion(&st->completion);  in spear_adc_probe()
338 	indio_dev->name = SPEAR_ADC_MOD_NAME;  in spear_adc_probe()
339 	indio_dev->info = &spear_adc_info;  in spear_adc_probe()
340 	indio_dev->modes = INDIO_DIRECT_MODE;  in spear_adc_probe()
341 	indio_dev->channels = spear_adc_iio_channels;  in spear_adc_probe()
342 	indio_dev->num_channels = ARRAY_SIZE(spear_adc_iio_channels);  in spear_adc_probe()
348 	dev_info(dev, "SPEAR ADC driver loaded, IRQ %d\n", irq);  in spear_adc_probe()
353 	clk_disable_unprepare(st->clk);  in spear_adc_probe()
363 	clk_disable_unprepare(st->clk);  in spear_adc_remove()
370 	{ .compatible = "st,spear600-adc", },
388 MODULE_DESCRIPTION("SPEAr ADC driver");