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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Sophgo CV1800B SARADC Driver4 *5 * Copyright (C) Bootlin 20246 * Author: Thomas Bonnefille <thomas.bonnefille@bootlin.com>7 */8 9#include <linux/array_size.h>10#include <linux/bitfield.h>11#include <linux/bits.h>12#include <linux/cleanup.h>13#include <linux/clk.h>14#include <linux/completion.h>15#include <linux/err.h>16#include <linux/interrupt.h>17#include <linux/iopoll.h>18#include <linux/mod_devicetable.h>19#include <linux/module.h>20#include <linux/mutex.h>21#include <linux/platform_device.h>22#include <linux/types.h>23 24#include <linux/iio/iio.h>25 26#define CV1800B_ADC_CTRL_REG 0x0427#define CV1800B_ADC_EN BIT(0)28#define CV1800B_ADC_SEL(x) BIT((x) + 5)29#define CV1800B_ADC_STATUS_REG 0x0830#define CV1800B_ADC_BUSY BIT(0)31#define CV1800B_ADC_CYC_SET_REG 0x0C32#define CV1800B_MASK_STARTUP_CYCLE GENMASK(4, 0)33#define CV1800B_MASK_SAMPLE_WINDOW GENMASK(11, 8)34#define CV1800B_MASK_CLKDIV GENMASK(15, 12)35#define CV1800B_MASK_COMPARE_CYCLE GENMASK(19, 16)36#define CV1800B_ADC_CH_RESULT_REG(x) (0x14 + 4 * (x))37#define CV1800B_ADC_CH_RESULT GENMASK(11, 0)38#define CV1800B_ADC_CH_VALID BIT(15)39#define CV1800B_ADC_INTR_EN_REG 0x2040#define CV1800B_ADC_INTR_CLR_REG 0x2441#define CV1800B_ADC_INTR_CLR_BIT BIT(0)42#define CV1800B_ADC_INTR_STA_REG 0x2843#define CV1800B_ADC_INTR_STA_BIT BIT(0)44#define CV1800B_READ_TIMEOUT_MS 100045#define CV1800B_READ_TIMEOUT_US (CV1800B_READ_TIMEOUT_MS * 1000)46 47#define CV1800B_ADC_CHANNEL(index) \48 { \49 .type = IIO_VOLTAGE, \50 .indexed = 1, \51 .channel = index, \52 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \53 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \54 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\55 .scan_index = index, \56 }57 58struct cv1800b_adc {59 struct completion completion;60 void __iomem *regs;61 struct mutex lock; /* ADC Control and Result register */62 struct clk *clk;63 int irq;64};65 66static const struct iio_chan_spec sophgo_channels[] = {67 CV1800B_ADC_CHANNEL(0),68 CV1800B_ADC_CHANNEL(1),69 CV1800B_ADC_CHANNEL(2),70};71 72static void cv1800b_adc_start_measurement(struct cv1800b_adc *saradc,73 int channel)74{75 writel(0, saradc->regs + CV1800B_ADC_CTRL_REG);76 writel(CV1800B_ADC_SEL(channel) | CV1800B_ADC_EN,77 saradc->regs + CV1800B_ADC_CTRL_REG);78}79 80static int cv1800b_adc_wait(struct cv1800b_adc *saradc)81{82 if (saradc->irq < 0) {83 u32 reg;84 85 return readl_poll_timeout(saradc->regs + CV1800B_ADC_STATUS_REG,86 reg, !(reg & CV1800B_ADC_BUSY),87 500, CV1800B_READ_TIMEOUT_US);88 }89 90 return wait_for_completion_timeout(&saradc->completion,91 msecs_to_jiffies(CV1800B_READ_TIMEOUT_MS)) > 0 ?92 0 : -ETIMEDOUT;93}94 95static int cv1800b_adc_read_raw(struct iio_dev *indio_dev,96 struct iio_chan_spec const *chan,97 int *val, int *val2, long mask)98{99 struct cv1800b_adc *saradc = iio_priv(indio_dev);100 101 switch (mask) {102 case IIO_CHAN_INFO_RAW: {103 u32 sample;104 105 scoped_guard(mutex, &saradc->lock) {106 int ret;107 108 cv1800b_adc_start_measurement(saradc, chan->scan_index);109 ret = cv1800b_adc_wait(saradc);110 if (ret < 0)111 return ret;112 113 sample = readl(saradc->regs + CV1800B_ADC_CH_RESULT_REG(chan->scan_index));114 }115 if (!(sample & CV1800B_ADC_CH_VALID))116 return -ENODATA;117 118 *val = sample & CV1800B_ADC_CH_RESULT;119 return IIO_VAL_INT;120 }121 case IIO_CHAN_INFO_SCALE:122 *val = 3300;123 *val2 = 12;124 return IIO_VAL_FRACTIONAL_LOG2;125 case IIO_CHAN_INFO_SAMP_FREQ: {126 u32 status_reg = readl(saradc->regs + CV1800B_ADC_CYC_SET_REG);127 unsigned int clk_div = (1 + FIELD_GET(CV1800B_MASK_CLKDIV, status_reg));128 unsigned int freq = clk_get_rate(saradc->clk) / clk_div;129 unsigned int nb_startup_cycle = 1 + FIELD_GET(CV1800B_MASK_STARTUP_CYCLE, status_reg);130 unsigned int nb_sample_cycle = 1 + FIELD_GET(CV1800B_MASK_SAMPLE_WINDOW, status_reg);131 unsigned int nb_compare_cycle = 1 + FIELD_GET(CV1800B_MASK_COMPARE_CYCLE, status_reg);132 133 *val = freq / (nb_startup_cycle + nb_sample_cycle + nb_compare_cycle);134 return IIO_VAL_INT;135 }136 default:137 return -EINVAL;138 }139}140 141static irqreturn_t cv1800b_adc_interrupt_handler(int irq, void *private)142{143 struct cv1800b_adc *saradc = private;144 u32 reg = readl(saradc->regs + CV1800B_ADC_INTR_STA_REG);145 146 if (!(FIELD_GET(CV1800B_ADC_INTR_STA_BIT, reg)))147 return IRQ_NONE;148 149 writel(CV1800B_ADC_INTR_CLR_BIT, saradc->regs + CV1800B_ADC_INTR_CLR_REG);150 complete(&saradc->completion);151 152 return IRQ_HANDLED;153}154 155static const struct iio_info cv1800b_adc_info = {156 .read_raw = &cv1800b_adc_read_raw,157};158 159static int cv1800b_adc_probe(struct platform_device *pdev)160{161 struct device *dev = &pdev->dev;162 struct cv1800b_adc *saradc;163 struct iio_dev *indio_dev;164 int ret;165 166 indio_dev = devm_iio_device_alloc(dev, sizeof(*saradc));167 if (!indio_dev)168 return -ENOMEM;169 170 saradc = iio_priv(indio_dev);171 indio_dev->name = "sophgo-cv1800b-adc";172 indio_dev->modes = INDIO_DIRECT_MODE;173 indio_dev->info = &cv1800b_adc_info;174 indio_dev->num_channels = ARRAY_SIZE(sophgo_channels);175 indio_dev->channels = sophgo_channels;176 177 saradc->clk = devm_clk_get_enabled(dev, NULL);178 if (IS_ERR(saradc->clk))179 return PTR_ERR(saradc->clk);180 181 saradc->regs = devm_platform_ioremap_resource(pdev, 0);182 if (IS_ERR(saradc->regs))183 return PTR_ERR(saradc->regs);184 185 saradc->irq = platform_get_irq_optional(pdev, 0);186 if (saradc->irq > 0) {187 init_completion(&saradc->completion);188 ret = devm_request_irq(dev, saradc->irq,189 cv1800b_adc_interrupt_handler, 0,190 dev_name(dev), saradc);191 if (ret)192 return ret;193 194 writel(1, saradc->regs + CV1800B_ADC_INTR_EN_REG);195 }196 197 ret = devm_mutex_init(dev, &saradc->lock);198 if (ret)199 return ret;200 201 writel(FIELD_PREP(CV1800B_MASK_STARTUP_CYCLE, 15) |202 FIELD_PREP(CV1800B_MASK_SAMPLE_WINDOW, 15) |203 FIELD_PREP(CV1800B_MASK_CLKDIV, 1) |204 FIELD_PREP(CV1800B_MASK_COMPARE_CYCLE, 15),205 saradc->regs + CV1800B_ADC_CYC_SET_REG);206 207 return devm_iio_device_register(dev, indio_dev);208}209 210static const struct of_device_id cv1800b_adc_match[] = {211 { .compatible = "sophgo,cv1800b-saradc", },212 { }213};214MODULE_DEVICE_TABLE(of, cv1800b_adc_match);215 216static struct platform_driver cv1800b_adc_driver = {217 .driver = {218 .name = "sophgo-cv1800b-saradc",219 .of_match_table = cv1800b_adc_match,220 },221 .probe = cv1800b_adc_probe,222};223module_platform_driver(cv1800b_adc_driver);224 225MODULE_AUTHOR("Thomas Bonnefille <thomas.bonnefille@bootlin.com>");226MODULE_DESCRIPTION("Sophgo CV1800B SARADC driver");227MODULE_LICENSE("GPL");228