1 // SPDX-License-Identifier: GPL-2.0-only
3  * IIO ADC driver for NXP LPC18xx ADC
8  *  - Hardware triggers
9  *  - Burst mode
10  *  - Interrupts
11  *  - DMA
27 /* LPC18XX ADC registers and bits */
70 static int lpc18xx_adc_read_chan(struct lpc18xx_adc *adc, unsigned int ch)  in lpc18xx_adc_read_chan()  argument
75 	reg = adc->cr_reg | BIT(ch) | LPC18XX_ADC_CR_START_NOW;  in lpc18xx_adc_read_chan()
76 	writel(reg, adc->base + LPC18XX_ADC_CR);  in lpc18xx_adc_read_chan()
78 	ret = readl_poll_timeout(adc->base + LPC18XX_ADC_GDR, reg,  in lpc18xx_adc_read_chan()
81 		dev_warn(adc->dev, "adc read timed out\n");  in lpc18xx_adc_read_chan()
92 	struct lpc18xx_adc *adc = iio_priv(indio_dev);  in lpc18xx_adc_read_raw()  local
96 		mutex_lock(&adc->lock);  in lpc18xx_adc_read_raw()
97 		*val = lpc18xx_adc_read_chan(adc, chan->channel);  in lpc18xx_adc_read_raw()
98 		mutex_unlock(&adc->lock);  in lpc18xx_adc_read_raw()
105 		*val = regulator_get_voltage(adc->vref) / 1000;  in lpc18xx_adc_read_raw()
111 	return -EINVAL;  in lpc18xx_adc_read_raw()
121 	struct lpc18xx_adc *adc;  in lpc18xx_adc_probe()  local
126 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));  in lpc18xx_adc_probe()
128 		return -ENOMEM;  in lpc18xx_adc_probe()
131 	adc = iio_priv(indio_dev);  in lpc18xx_adc_probe()
132 	adc->dev = &pdev->dev;  in lpc18xx_adc_probe()
133 	mutex_init(&adc->lock);  in lpc18xx_adc_probe()
135 	adc->base = devm_platform_ioremap_resource(pdev, 0);  in lpc18xx_adc_probe()
136 	if (IS_ERR(adc->base))  in lpc18xx_adc_probe()
137 		return PTR_ERR(adc->base);  in lpc18xx_adc_probe()
139 	adc->clk = devm_clk_get(&pdev->dev, NULL);  in lpc18xx_adc_probe()
140 	if (IS_ERR(adc->clk)) {  in lpc18xx_adc_probe()
141 		dev_err(&pdev->dev, "error getting clock\n");  in lpc18xx_adc_probe()
142 		return PTR_ERR(adc->clk);  in lpc18xx_adc_probe()
145 	rate = clk_get_rate(adc->clk);  in lpc18xx_adc_probe()
148 	adc->vref = devm_regulator_get(&pdev->dev, "vref");  in lpc18xx_adc_probe()
149 	if (IS_ERR(adc->vref)) {  in lpc18xx_adc_probe()
150 		dev_err(&pdev->dev, "error getting regulator\n");  in lpc18xx_adc_probe()
151 		return PTR_ERR(adc->vref);  in lpc18xx_adc_probe()
154 	indio_dev->name = dev_name(&pdev->dev);  in lpc18xx_adc_probe()
155 	indio_dev->info = &lpc18xx_adc_info;  in lpc18xx_adc_probe()
156 	indio_dev->modes = INDIO_DIRECT_MODE;  in lpc18xx_adc_probe()
157 	indio_dev->channels = lpc18xx_adc_iio_channels;  in lpc18xx_adc_probe()
158 	indio_dev->num_channels = ARRAY_SIZE(lpc18xx_adc_iio_channels);  in lpc18xx_adc_probe()
160 	ret = regulator_enable(adc->vref);  in lpc18xx_adc_probe()
162 		dev_err(&pdev->dev, "unable to enable regulator\n");  in lpc18xx_adc_probe()
166 	ret = clk_prepare_enable(adc->clk);  in lpc18xx_adc_probe()
168 		dev_err(&pdev->dev, "unable to enable clock\n");  in lpc18xx_adc_probe()
172 	adc->cr_reg = (clkdiv << LPC18XX_ADC_CR_CLKDIV_SHIFT) |  in lpc18xx_adc_probe()
174 	writel(adc->cr_reg, adc->base + LPC18XX_ADC_CR);  in lpc18xx_adc_probe()
178 		dev_err(&pdev->dev, "unable to register device\n");  in lpc18xx_adc_probe()
185 	writel(0, adc->base + LPC18XX_ADC_CR);  in lpc18xx_adc_probe()
186 	clk_disable_unprepare(adc->clk);  in lpc18xx_adc_probe()
188 	regulator_disable(adc->vref);  in lpc18xx_adc_probe()
195 	struct lpc18xx_adc *adc = iio_priv(indio_dev);  in lpc18xx_adc_remove()  local
199 	writel(0, adc->base + LPC18XX_ADC_CR);  in lpc18xx_adc_remove()
200 	clk_disable_unprepare(adc->clk);  in lpc18xx_adc_remove()
201 	regulator_disable(adc->vref);  in lpc18xx_adc_remove()
207 	{ .compatible = "nxp,lpc1850-adc" },
216 		.name = "lpc18xx-adc",
222 MODULE_DESCRIPTION("LPC18xx ADC driver");