diff options
Diffstat (limited to 'drivers/iio/adc/ingenic-adc.c')
| -rw-r--r-- | drivers/iio/adc/ingenic-adc.c | 848 |
1 files changed, 848 insertions, 0 deletions
diff --git a/drivers/iio/adc/ingenic-adc.c b/drivers/iio/adc/ingenic-adc.c new file mode 100644 index 000000000..1aafbe2cf --- /dev/null +++ b/drivers/iio/adc/ingenic-adc.c @@ -0,0 +1,848 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ADC driver for the Ingenic JZ47xx SoCs + * Copyright (c) 2019 Artur Rojek <contact@artur-rojek.eu> + * + * based on drivers/mfd/jz4740-adc.c + */ + +#include <dt-bindings/iio/adc/ingenic,adc.h> +#include <linux/clk.h> +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/mutex.h> +#include <linux/platform_device.h> + +#define JZ_ADC_REG_ENABLE 0x00 +#define JZ_ADC_REG_CFG 0x04 +#define JZ_ADC_REG_CTRL 0x08 +#define JZ_ADC_REG_STATUS 0x0c +#define JZ_ADC_REG_ADSAME 0x10 +#define JZ_ADC_REG_ADWAIT 0x14 +#define JZ_ADC_REG_ADTCH 0x18 +#define JZ_ADC_REG_ADBDAT 0x1c +#define JZ_ADC_REG_ADSDAT 0x20 +#define JZ_ADC_REG_ADCMD 0x24 +#define JZ_ADC_REG_ADCLK 0x28 + +#define JZ_ADC_REG_ENABLE_PD BIT(7) +#define JZ_ADC_REG_CFG_AUX_MD (BIT(0) | BIT(1)) +#define JZ_ADC_REG_CFG_BAT_MD BIT(4) +#define JZ_ADC_REG_CFG_SAMPLE_NUM(n) ((n) << 10) +#define JZ_ADC_REG_CFG_PULL_UP(n) ((n) << 16) +#define JZ_ADC_REG_CFG_CMD_SEL BIT(22) +#define JZ_ADC_REG_CFG_TOUCH_OPS_MASK (BIT(31) | GENMASK(23, 10)) +#define JZ_ADC_REG_ADCLK_CLKDIV_LSB 0 +#define JZ4725B_ADC_REG_ADCLK_CLKDIV10US_LSB 16 +#define JZ4770_ADC_REG_ADCLK_CLKDIV10US_LSB 8 +#define JZ4770_ADC_REG_ADCLK_CLKDIVMS_LSB 16 + +#define JZ_ADC_REG_ADCMD_YNADC BIT(7) +#define JZ_ADC_REG_ADCMD_YPADC BIT(8) +#define JZ_ADC_REG_ADCMD_XNADC BIT(9) +#define JZ_ADC_REG_ADCMD_XPADC BIT(10) +#define JZ_ADC_REG_ADCMD_VREFPYP BIT(11) +#define JZ_ADC_REG_ADCMD_VREFPXP BIT(12) +#define JZ_ADC_REG_ADCMD_VREFPXN BIT(13) +#define JZ_ADC_REG_ADCMD_VREFPAUX BIT(14) +#define JZ_ADC_REG_ADCMD_VREFPVDD33 BIT(15) +#define JZ_ADC_REG_ADCMD_VREFNYN BIT(16) +#define JZ_ADC_REG_ADCMD_VREFNXP BIT(17) +#define JZ_ADC_REG_ADCMD_VREFNXN BIT(18) +#define JZ_ADC_REG_ADCMD_VREFAUX BIT(19) +#define JZ_ADC_REG_ADCMD_YNGRU BIT(20) +#define JZ_ADC_REG_ADCMD_XNGRU BIT(21) +#define JZ_ADC_REG_ADCMD_XPGRU BIT(22) +#define JZ_ADC_REG_ADCMD_YPSUP BIT(23) +#define JZ_ADC_REG_ADCMD_XNSUP BIT(24) +#define JZ_ADC_REG_ADCMD_XPSUP BIT(25) + +#define JZ_ADC_AUX_VREF 3300 +#define JZ_ADC_AUX_VREF_BITS 12 +#define JZ_ADC_BATTERY_LOW_VREF 2500 +#define JZ_ADC_BATTERY_LOW_VREF_BITS 12 +#define JZ4725B_ADC_BATTERY_HIGH_VREF 7500 +#define JZ4725B_ADC_BATTERY_HIGH_VREF_BITS 10 +#define JZ4740_ADC_BATTERY_HIGH_VREF (7500 * 0.986) +#define JZ4740_ADC_BATTERY_HIGH_VREF_BITS 12 +#define JZ4770_ADC_BATTERY_VREF 1200 +#define JZ4770_ADC_BATTERY_VREF_BITS 12 + +#define JZ_ADC_IRQ_AUX BIT(0) +#define JZ_ADC_IRQ_BATTERY BIT(1) +#define JZ_ADC_IRQ_TOUCH BIT(2) +#define JZ_ADC_IRQ_PEN_DOWN BIT(3) +#define JZ_ADC_IRQ_PEN_UP BIT(4) +#define JZ_ADC_IRQ_PEN_DOWN_SLEEP BIT(5) +#define JZ_ADC_IRQ_SLEEP BIT(7) + +struct ingenic_adc; + +struct ingenic_adc_soc_data { + unsigned int battery_high_vref; + unsigned int battery_high_vref_bits; + const int *battery_raw_avail; + size_t battery_raw_avail_size; + const int *battery_scale_avail; + size_t battery_scale_avail_size; + unsigned int battery_vref_mode: 1; + unsigned int has_aux2: 1; + const struct iio_chan_spec *channels; + unsigned int num_channels; + int (*init_clk_div)(struct device *dev, struct ingenic_adc *adc); +}; + +struct ingenic_adc { + void __iomem *base; + struct clk *clk; + struct mutex lock; + struct mutex aux_lock; + const struct ingenic_adc_soc_data *soc_data; + bool low_vref_mode; +}; + +static void ingenic_adc_set_adcmd(struct iio_dev *iio_dev, unsigned long mask) +{ + struct ingenic_adc *adc = iio_priv(iio_dev); + + mutex_lock(&adc->lock); + + /* Init ADCMD */ + readl(adc->base + JZ_ADC_REG_ADCMD); + + if (mask & 0x3) { + /* Second channel (INGENIC_ADC_TOUCH_YP): sample YP vs. GND */ + writel(JZ_ADC_REG_ADCMD_XNGRU + | JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33 + | JZ_ADC_REG_ADCMD_YPADC, + adc->base + JZ_ADC_REG_ADCMD); + + /* First channel (INGENIC_ADC_TOUCH_XP): sample XP vs. GND */ + writel(JZ_ADC_REG_ADCMD_YNGRU + | JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33 + | JZ_ADC_REG_ADCMD_XPADC, + adc->base + JZ_ADC_REG_ADCMD); + } + + if (mask & 0xc) { + /* Fourth channel (INGENIC_ADC_TOUCH_YN): sample YN vs. GND */ + writel(JZ_ADC_REG_ADCMD_XNGRU + | JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33 + | JZ_ADC_REG_ADCMD_YNADC, + adc->base + JZ_ADC_REG_ADCMD); + + /* Third channel (INGENIC_ADC_TOUCH_XN): sample XN vs. GND */ + writel(JZ_ADC_REG_ADCMD_YNGRU + | JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33 + | JZ_ADC_REG_ADCMD_XNADC, + adc->base + JZ_ADC_REG_ADCMD); + } + + if (mask & 0x30) { + /* Sixth channel (INGENIC_ADC_TOUCH_YD): sample YP vs. YN */ + writel(JZ_ADC_REG_ADCMD_VREFNYN | JZ_ADC_REG_ADCMD_VREFPVDD33 + | JZ_ADC_REG_ADCMD_YPADC, + adc->base + JZ_ADC_REG_ADCMD); + + /* Fifth channel (INGENIC_ADC_TOUCH_XD): sample XP vs. XN */ + writel(JZ_ADC_REG_ADCMD_VREFNXN | JZ_ADC_REG_ADCMD_VREFPVDD33 + | JZ_ADC_REG_ADCMD_XPADC, + adc->base + JZ_ADC_REG_ADCMD); + } + + /* We're done */ + writel(0, adc->base + JZ_ADC_REG_ADCMD); + + mutex_unlock(&adc->lock); +} + +static void ingenic_adc_set_config(struct ingenic_adc *adc, + uint32_t mask, + uint32_t val) +{ + uint32_t cfg; + + mutex_lock(&adc->lock); + + cfg = readl(adc->base + JZ_ADC_REG_CFG) & ~mask; + cfg |= val; + writel(cfg, adc->base + JZ_ADC_REG_CFG); + + mutex_unlock(&adc->lock); +} + +static void ingenic_adc_enable_unlocked(struct ingenic_adc *adc, + int engine, + bool enabled) +{ + u8 val; + + val = readb(adc->base + JZ_ADC_REG_ENABLE); + + if (enabled) + val |= BIT(engine); + else + val &= ~BIT(engine); + + writeb(val, adc->base + JZ_ADC_REG_ENABLE); +} + +static void ingenic_adc_enable(struct ingenic_adc *adc, + int engine, + bool enabled) +{ + mutex_lock(&adc->lock); + ingenic_adc_enable_unlocked(adc, engine, enabled); + mutex_unlock(&adc->lock); +} + +static int ingenic_adc_capture(struct ingenic_adc *adc, + int engine) +{ + u32 cfg; + u8 val; + int ret; + + /* + * Disable CMD_SEL temporarily, because it causes wrong VBAT readings, + * probably due to the switch of VREF. We must keep the lock here to + * avoid races with the buffer enable/disable functions. + */ + mutex_lock(&adc->lock); + cfg = readl(adc->base + JZ_ADC_REG_CFG); + writel(cfg & ~JZ_ADC_REG_CFG_CMD_SEL, adc->base + JZ_ADC_REG_CFG); + + ingenic_adc_enable_unlocked(adc, engine, true); + ret = readb_poll_timeout(adc->base + JZ_ADC_REG_ENABLE, val, + !(val & BIT(engine)), 250, 1000); + if (ret) + ingenic_adc_enable_unlocked(adc, engine, false); + + writel(cfg, adc->base + JZ_ADC_REG_CFG); + mutex_unlock(&adc->lock); + + return ret; +} + +static int ingenic_adc_write_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + int val, + int val2, + long m) +{ + struct ingenic_adc *adc = iio_priv(iio_dev); + struct device *dev = iio_dev->dev.parent; + int ret; + + switch (m) { + case IIO_CHAN_INFO_SCALE: + switch (chan->channel) { + case INGENIC_ADC_BATTERY: + if (!adc->soc_data->battery_vref_mode) + return -EINVAL; + + ret = clk_enable(adc->clk); + if (ret) { + dev_err(dev, "Failed to enable clock: %d\n", + ret); + return ret; + } + + if (val > JZ_ADC_BATTERY_LOW_VREF) { + ingenic_adc_set_config(adc, + JZ_ADC_REG_CFG_BAT_MD, + 0); + adc->low_vref_mode = false; + } else { + ingenic_adc_set_config(adc, + JZ_ADC_REG_CFG_BAT_MD, + JZ_ADC_REG_CFG_BAT_MD); + adc->low_vref_mode = true; + } + + clk_disable(adc->clk); + + return 0; + default: + return -EINVAL; + } + default: + return -EINVAL; + } +} + +static const int jz4725b_adc_battery_raw_avail[] = { + 0, 1, (1 << JZ_ADC_BATTERY_LOW_VREF_BITS) - 1, +}; + +static const int jz4725b_adc_battery_scale_avail[] = { + JZ4725B_ADC_BATTERY_HIGH_VREF, JZ4725B_ADC_BATTERY_HIGH_VREF_BITS, + JZ_ADC_BATTERY_LOW_VREF, JZ_ADC_BATTERY_LOW_VREF_BITS, +}; + +static const int jz4740_adc_battery_raw_avail[] = { + 0, 1, (1 << JZ_ADC_BATTERY_LOW_VREF_BITS) - 1, +}; + +static const int jz4740_adc_battery_scale_avail[] = { + JZ4740_ADC_BATTERY_HIGH_VREF, JZ4740_ADC_BATTERY_HIGH_VREF_BITS, + JZ_ADC_BATTERY_LOW_VREF, JZ_ADC_BATTERY_LOW_VREF_BITS, +}; + +static const int jz4770_adc_battery_raw_avail[] = { + 0, 1, (1 << JZ4770_ADC_BATTERY_VREF_BITS) - 1, +}; + +static const int jz4770_adc_battery_scale_avail[] = { + JZ4770_ADC_BATTERY_VREF, JZ4770_ADC_BATTERY_VREF_BITS, +}; + +static int jz4725b_adc_init_clk_div(struct device *dev, struct ingenic_adc *adc) +{ + struct clk *parent_clk; + unsigned long parent_rate, rate; + unsigned int div_main, div_10us; + + parent_clk = clk_get_parent(adc->clk); + if (!parent_clk) { + dev_err(dev, "ADC clock has no parent\n"); + return -ENODEV; + } + parent_rate = clk_get_rate(parent_clk); + + /* + * The JZ4725B ADC works at 500 kHz to 8 MHz. + * We pick the highest rate possible. + * In practice we typically get 6 MHz, half of the 12 MHz EXT clock. + */ + div_main = DIV_ROUND_UP(parent_rate, 8000000); + div_main = clamp(div_main, 1u, 64u); + rate = parent_rate / div_main; + if (rate < 500000 || rate > 8000000) { + dev_err(dev, "No valid divider for ADC main clock\n"); + return -EINVAL; + } + + /* We also need a divider that produces a 10us clock. */ + div_10us = DIV_ROUND_UP(rate, 100000); + + writel(((div_10us - 1) << JZ4725B_ADC_REG_ADCLK_CLKDIV10US_LSB) | + (div_main - 1) << JZ_ADC_REG_ADCLK_CLKDIV_LSB, + adc->base + JZ_ADC_REG_ADCLK); + + return 0; +} + +static int jz4770_adc_init_clk_div(struct device *dev, struct ingenic_adc *adc) +{ + struct clk *parent_clk; + unsigned long parent_rate, rate; + unsigned int div_main, div_ms, div_10us; + + parent_clk = clk_get_parent(adc->clk); + if (!parent_clk) { + dev_err(dev, "ADC clock has no parent\n"); + return -ENODEV; + } + parent_rate = clk_get_rate(parent_clk); + + /* + * The JZ4770 ADC works at 20 kHz to 200 kHz. + * We pick the highest rate possible. + */ + div_main = DIV_ROUND_UP(parent_rate, 200000); + div_main = clamp(div_main, 1u, 256u); + rate = parent_rate / div_main; + if (rate < 20000 || rate > 200000) { + dev_err(dev, "No valid divider for ADC main clock\n"); + return -EINVAL; + } + + /* We also need a divider that produces a 10us clock. */ + div_10us = DIV_ROUND_UP(rate, 10000); + /* And another, which produces a 1ms clock. */ + div_ms = DIV_ROUND_UP(rate, 1000); + + writel(((div_ms - 1) << JZ4770_ADC_REG_ADCLK_CLKDIVMS_LSB) | + ((div_10us - 1) << JZ4770_ADC_REG_ADCLK_CLKDIV10US_LSB) | + (div_main - 1) << JZ_ADC_REG_ADCLK_CLKDIV_LSB, + adc->base + JZ_ADC_REG_ADCLK); + + return 0; +} + +static const struct iio_chan_spec jz4740_channels[] = { + { + .extend_name = "aux", + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .indexed = 1, + .channel = INGENIC_ADC_AUX, + .scan_index = -1, + }, + { + .extend_name = "battery", + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .indexed = 1, + .channel = INGENIC_ADC_BATTERY, + .scan_index = -1, + }, +}; + +static const struct iio_chan_spec jz4770_channels[] = { + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = INGENIC_ADC_TOUCH_XP, + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + }, + }, + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = INGENIC_ADC_TOUCH_YP, + .scan_index = 1, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + }, + }, + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = INGENIC_ADC_TOUCH_XN, + .scan_index = 2, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + }, + }, + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = INGENIC_ADC_TOUCH_YN, + .scan_index = 3, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + }, + }, + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = INGENIC_ADC_TOUCH_XD, + .scan_index = 4, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + }, + }, + { + .type = IIO_VOLTAGE, + .indexed = 1, + .channel = INGENIC_ADC_TOUCH_YD, + .scan_index = 5, + .scan_type = { + .sign = 'u', + .realbits = 12, + .storagebits = 16, + }, + }, + { + .extend_name = "aux", + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .indexed = 1, + .channel = INGENIC_ADC_AUX, + .scan_index = -1, + }, + { + .extend_name = "battery", + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .indexed = 1, + .channel = INGENIC_ADC_BATTERY, + .scan_index = -1, + }, + { + .extend_name = "aux2", + .type = IIO_VOLTAGE, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .indexed = 1, + .channel = INGENIC_ADC_AUX2, + .scan_index = -1, + }, +}; + +static const struct ingenic_adc_soc_data jz4725b_adc_soc_data = { + .battery_high_vref = JZ4725B_ADC_BATTERY_HIGH_VREF, + .battery_high_vref_bits = JZ4725B_ADC_BATTERY_HIGH_VREF_BITS, + .battery_raw_avail = jz4725b_adc_battery_raw_avail, + .battery_raw_avail_size = ARRAY_SIZE(jz4725b_adc_battery_raw_avail), + .battery_scale_avail = jz4725b_adc_battery_scale_avail, + .battery_scale_avail_size = ARRAY_SIZE(jz4725b_adc_battery_scale_avail), + .battery_vref_mode = true, + .has_aux2 = false, + .channels = jz4740_channels, + .num_channels = ARRAY_SIZE(jz4740_channels), + .init_clk_div = jz4725b_adc_init_clk_div, +}; + +static const struct ingenic_adc_soc_data jz4740_adc_soc_data = { + .battery_high_vref = JZ4740_ADC_BATTERY_HIGH_VREF, + .battery_high_vref_bits = JZ4740_ADC_BATTERY_HIGH_VREF_BITS, + .battery_raw_avail = jz4740_adc_battery_raw_avail, + .battery_raw_avail_size = ARRAY_SIZE(jz4740_adc_battery_raw_avail), + .battery_scale_avail = jz4740_adc_battery_scale_avail, + .battery_scale_avail_size = ARRAY_SIZE(jz4740_adc_battery_scale_avail), + .battery_vref_mode = true, + .has_aux2 = false, + .channels = jz4740_channels, + .num_channels = ARRAY_SIZE(jz4740_channels), + .init_clk_div = NULL, /* no ADCLK register on JZ4740 */ +}; + +static const struct ingenic_adc_soc_data jz4770_adc_soc_data = { + .battery_high_vref = JZ4770_ADC_BATTERY_VREF, + .battery_high_vref_bits = JZ4770_ADC_BATTERY_VREF_BITS, + .battery_raw_avail = jz4770_adc_battery_raw_avail, + .battery_raw_avail_size = ARRAY_SIZE(jz4770_adc_battery_raw_avail), + .battery_scale_avail = jz4770_adc_battery_scale_avail, + .battery_scale_avail_size = ARRAY_SIZE(jz4770_adc_battery_scale_avail), + .battery_vref_mode = false, + .has_aux2 = true, + .channels = jz4770_channels, + .num_channels = ARRAY_SIZE(jz4770_channels), + .init_clk_div = jz4770_adc_init_clk_div, +}; + +static int ingenic_adc_read_avail(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + const int **vals, + int *type, + int *length, + long m) +{ + struct ingenic_adc *adc = iio_priv(iio_dev); + + switch (m) { + case IIO_CHAN_INFO_RAW: + *type = IIO_VAL_INT; + *length = adc->soc_data->battery_raw_avail_size; + *vals = adc->soc_data->battery_raw_avail; + return IIO_AVAIL_RANGE; + case IIO_CHAN_INFO_SCALE: + *type = IIO_VAL_FRACTIONAL_LOG2; + *length = adc->soc_data->battery_scale_avail_size; + *vals = adc->soc_data->battery_scale_avail; + return IIO_AVAIL_LIST; + default: + return -EINVAL; + }; +} + +static int ingenic_adc_read_chan_info_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + int *val) +{ + int bit, ret, engine = (chan->channel == INGENIC_ADC_BATTERY); + struct ingenic_adc *adc = iio_priv(iio_dev); + + ret = clk_enable(adc->clk); + if (ret) { + dev_err(iio_dev->dev.parent, "Failed to enable clock: %d\n", + ret); + return ret; + } + + /* We cannot sample AUX/AUX2 in parallel. */ + mutex_lock(&adc->aux_lock); + if (adc->soc_data->has_aux2 && engine == 0) { + bit = BIT(chan->channel == INGENIC_ADC_AUX2); + ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_AUX_MD, bit); + } + + ret = ingenic_adc_capture(adc, engine); + if (ret) + goto out; + + switch (chan->channel) { + case INGENIC_ADC_AUX: + case INGENIC_ADC_AUX2: + *val = readw(adc->base + JZ_ADC_REG_ADSDAT); + break; + case INGENIC_ADC_BATTERY: + *val = readw(adc->base + JZ_ADC_REG_ADBDAT); + break; + } + + ret = IIO_VAL_INT; +out: + mutex_unlock(&adc->aux_lock); + clk_disable(adc->clk); + + return ret; +} + +static int ingenic_adc_read_raw(struct iio_dev *iio_dev, + struct iio_chan_spec const *chan, + int *val, + int *val2, + long m) +{ + struct ingenic_adc *adc = iio_priv(iio_dev); + + switch (m) { + case IIO_CHAN_INFO_RAW: + return ingenic_adc_read_chan_info_raw(iio_dev, chan, val); + case IIO_CHAN_INFO_SCALE: + switch (chan->channel) { + case INGENIC_ADC_AUX: + case INGENIC_ADC_AUX2: + *val = JZ_ADC_AUX_VREF; + *val2 = JZ_ADC_AUX_VREF_BITS; + break; + case INGENIC_ADC_BATTERY: + if (adc->low_vref_mode) { + *val = JZ_ADC_BATTERY_LOW_VREF; + *val2 = JZ_ADC_BATTERY_LOW_VREF_BITS; + } else { + *val = adc->soc_data->battery_high_vref; + *val2 = adc->soc_data->battery_high_vref_bits; + } + break; + } + + return IIO_VAL_FRACTIONAL_LOG2; + default: + return -EINVAL; + } +} + +static int ingenic_adc_of_xlate(struct iio_dev *iio_dev, + const struct of_phandle_args *iiospec) +{ + int i; + + if (!iiospec->args_count) + return -EINVAL; + + for (i = 0; i < iio_dev->num_channels; ++i) + if (iio_dev->channels[i].channel == iiospec->args[0]) + return i; + + return -EINVAL; +} + +static void ingenic_adc_clk_cleanup(void *data) +{ + clk_unprepare(data); +} + +static const struct iio_info ingenic_adc_info = { + .write_raw = ingenic_adc_write_raw, + .read_raw = ingenic_adc_read_raw, + .read_avail = ingenic_adc_read_avail, + .of_xlate = ingenic_adc_of_xlate, +}; + +static int ingenic_adc_buffer_enable(struct iio_dev *iio_dev) +{ + struct ingenic_adc *adc = iio_priv(iio_dev); + int ret; + + ret = clk_enable(adc->clk); + if (ret) { + dev_err(iio_dev->dev.parent, "Failed to enable clock: %d\n", + ret); + return ret; + } + + /* It takes significant time for the touchscreen hw to stabilize. */ + msleep(50); + ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_TOUCH_OPS_MASK, + JZ_ADC_REG_CFG_SAMPLE_NUM(4) | + JZ_ADC_REG_CFG_PULL_UP(4)); + + writew(80, adc->base + JZ_ADC_REG_ADWAIT); + writew(2, adc->base + JZ_ADC_REG_ADSAME); + writeb((u8)~JZ_ADC_IRQ_TOUCH, adc->base + JZ_ADC_REG_CTRL); + writel(0, adc->base + JZ_ADC_REG_ADTCH); + + ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_CMD_SEL, + JZ_ADC_REG_CFG_CMD_SEL); + ingenic_adc_set_adcmd(iio_dev, iio_dev->active_scan_mask[0]); + + ingenic_adc_enable(adc, 2, true); + + return 0; +} + +static int ingenic_adc_buffer_disable(struct iio_dev *iio_dev) +{ + struct ingenic_adc *adc = iio_priv(iio_dev); + + ingenic_adc_enable(adc, 2, false); + + ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_CMD_SEL, 0); + + writeb(0xff, adc->base + JZ_ADC_REG_CTRL); + writeb(0xff, adc->base + JZ_ADC_REG_STATUS); + ingenic_adc_set_config(adc, JZ_ADC_REG_CFG_TOUCH_OPS_MASK, 0); + writew(0, adc->base + JZ_ADC_REG_ADSAME); + writew(0, adc->base + JZ_ADC_REG_ADWAIT); + clk_disable(adc->clk); + + return 0; +} + +static const struct iio_buffer_setup_ops ingenic_buffer_setup_ops = { + .postenable = &ingenic_adc_buffer_enable, + .predisable = &ingenic_adc_buffer_disable +}; + +static irqreturn_t ingenic_adc_irq(int irq, void *data) +{ + struct iio_dev *iio_dev = data; + struct ingenic_adc *adc = iio_priv(iio_dev); + unsigned long mask = iio_dev->active_scan_mask[0]; + unsigned int i; + u32 tdat[3]; + + for (i = 0; i < ARRAY_SIZE(tdat); mask >>= 2, i++) { + if (mask & 0x3) + tdat[i] = readl(adc->base + JZ_ADC_REG_ADTCH); + else + tdat[i] = 0; + } + + iio_push_to_buffers(iio_dev, tdat); + writeb(JZ_ADC_IRQ_TOUCH, adc->base + JZ_ADC_REG_STATUS); + + return IRQ_HANDLED; +} + +static int ingenic_adc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct iio_dev *iio_dev; + struct ingenic_adc *adc; + const struct ingenic_adc_soc_data *soc_data; + int irq, ret; + + soc_data = device_get_match_data(dev); + if (!soc_data) + return -EINVAL; + + iio_dev = devm_iio_device_alloc(dev, sizeof(*adc)); + if (!iio_dev) + return -ENOMEM; + + adc = iio_priv(iio_dev); + mutex_init(&adc->lock); + mutex_init(&adc->aux_lock); + adc->soc_data = soc_data; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = devm_request_irq(dev, irq, ingenic_adc_irq, 0, + dev_name(dev), iio_dev); + if (ret < 0) { + dev_err(dev, "Failed to request irq: %d\n", ret); + return ret; + } + + adc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(adc->base)) + return PTR_ERR(adc->base); + + adc->clk = devm_clk_get(dev, "adc"); + if (IS_ERR(adc->clk)) { + dev_err(dev, "Unable to get clock\n"); + return PTR_ERR(adc->clk); + } + + ret = clk_prepare_enable(adc->clk); + if (ret) { + dev_err(dev, "Failed to enable clock\n"); + return ret; + } + + /* Set clock dividers. */ + if (soc_data->init_clk_div) { + ret = soc_data->init_clk_div(dev, adc); + if (ret) { + clk_disable_unprepare(adc->clk); + return ret; + } + } + + /* Put hardware in a known passive state. */ + writeb(0x00, adc->base + JZ_ADC_REG_ENABLE); + writeb(0xff, adc->base + JZ_ADC_REG_CTRL); + usleep_range(2000, 3000); /* Must wait at least 2ms. */ + clk_disable(adc->clk); + + ret = devm_add_action_or_reset(dev, ingenic_adc_clk_cleanup, adc->clk); + if (ret) { + dev_err(dev, "Unable to add action\n"); + return ret; + } + + iio_dev->name = "jz-adc"; + iio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; + iio_dev->setup_ops = &ingenic_buffer_setup_ops; + iio_dev->channels = soc_data->channels; + iio_dev->num_channels = soc_data->num_channels; + iio_dev->info = &ingenic_adc_info; + + ret = devm_iio_device_register(dev, iio_dev); + if (ret) + dev_err(dev, "Unable to register IIO device\n"); + + return ret; +} + +static const struct of_device_id ingenic_adc_of_match[] = { + { .compatible = "ingenic,jz4725b-adc", .data = &jz4725b_adc_soc_data, }, + { .compatible = "ingenic,jz4740-adc", .data = &jz4740_adc_soc_data, }, + { .compatible = "ingenic,jz4770-adc", .data = &jz4770_adc_soc_data, }, + { }, +}; +MODULE_DEVICE_TABLE(of, ingenic_adc_of_match); + +static struct platform_driver ingenic_adc_driver = { + .driver = { + .name = "ingenic-adc", + .of_match_table = ingenic_adc_of_match, + }, + .probe = ingenic_adc_probe, +}; +module_platform_driver(ingenic_adc_driver); +MODULE_LICENSE("GPL v2"); |