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Subject[PATCH v2 3/3] IIO: add Ingenic JZ47xx ADC driver.
Date
Add an IIO driver for the ADC hardware present on Ingenic JZ47xx SoCs.

Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
---

Changes:

v2: - prefix all platform defines with JZ_ADC_*,
- replace spinlock with a mutex,
- change devm_add_action to devm_add_action_or_reset,
- add a function wrapper for clk_unprepare,
- change iio_dev->name from "adc" to "jz-adc",
- simplify error handling code for devm_iio_device_register

drivers/iio/adc/Kconfig | 9 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ingenic-adc.c | 363 ++++++++++++++++++++++++++++++++++
3 files changed, 373 insertions(+)
create mode 100644 drivers/iio/adc/ingenic-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 7a3ca4ec0cb7..f9f349a22b04 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -367,6 +367,15 @@ config INA2XX_ADC
Say yes here to build support for TI INA2xx family of Power Monitors.
This driver is mutually exclusive with the HWMON version.

+config INGENIC_ADC
+ tristate "Ingenic JZ47xx SoCs ADC driver"
+ depends on MIPS || COMPILE_TEST
+ help
+ Say yes here to build support for the Ingenic JZ47xx SoCs ADC unit.
+
+ This driver can also be built as a module. If so, the module will be
+ called ingenic_adc.
+
config IMX7D_ADC
tristate "Freescale IMX7D ADC driver"
depends on ARCH_MXC || COMPILE_TEST
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 07df37f621bd..0a7acab33b91 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_HI8435) += hi8435.o
obj-$(CONFIG_HX711) += hx711.o
obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
+obj-$(CONFIG_INGENIC_ADC) += ingenic-adc.o
obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
diff --git a/drivers/iio/adc/ingenic-adc.c b/drivers/iio/adc/ingenic-adc.c
new file mode 100644
index 000000000000..1f436df1fd45
--- /dev/null
+++ b/drivers/iio/adc/ingenic-adc.c
@@ -0,0 +1,363 @@
+// 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/iio.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.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_ADTCH 0x18
+#define JZ_ADC_REG_ADBDAT 0x1c
+#define JZ_ADC_REG_ADSDAT 0x20
+
+#define JZ_ADC_REG_CFG_BAT_MD BIT(4)
+
+#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
+
+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;
+};
+
+struct ingenic_adc {
+ void __iomem *base;
+ struct clk *clk;
+ struct mutex lock;
+ const struct ingenic_adc_soc_data *soc_data;
+ bool low_vref_mode;
+};
+
+static void ingenic_adc_set_config(struct ingenic_adc *adc,
+ uint32_t mask,
+ uint32_t val)
+{
+ uint32_t cfg;
+
+ clk_enable(adc->clk);
+ 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);
+ clk_disable(adc->clk);
+}
+
+static void ingenic_adc_enable(struct ingenic_adc *adc,
+ int engine,
+ bool enabled)
+{
+ u8 val;
+
+ mutex_lock(&adc->lock);
+ 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);
+ mutex_unlock(&adc->lock);
+}
+
+static int ingenic_adc_capture(struct ingenic_adc *adc,
+ int engine)
+{
+ u8 val;
+ int ret;
+
+ ingenic_adc_enable(adc, engine, true);
+ ret = readb_poll_timeout(adc->base + JZ_ADC_REG_ENABLE, val,
+ !(val & BIT(engine)), 250, 1000);
+ if (ret)
+ ingenic_adc_enable(adc, engine, false);
+
+ 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);
+
+ switch (m) {
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->channel) {
+ case INGENIC_ADC_BATTERY:
+ 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;
+ }
+ 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 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),
+};
+
+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),
+};
+
+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_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);
+ int ret;
+
+ switch (m) {
+ case IIO_CHAN_INFO_RAW:
+ clk_enable(adc->clk);
+ ret = ingenic_adc_capture(adc, chan->channel);
+ if (ret) {
+ clk_disable(adc->clk);
+ return ret;
+ }
+
+ switch (chan->channel) {
+ case INGENIC_ADC_AUX:
+ *val = readw(adc->base + JZ_ADC_REG_ADSDAT);
+ break;
+ case INGENIC_ADC_BATTERY:
+ *val = readw(adc->base + JZ_ADC_REG_ADBDAT);
+ break;
+ }
+
+ clk_disable(adc->clk);
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ switch (chan->channel) {
+ case INGENIC_ADC_AUX:
+ *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 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,
+};
+
+static const struct iio_chan_spec ingenic_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,
+ },
+ {
+ .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,
+ },
+};
+
+static int ingenic_adc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct iio_dev *iio_dev;
+ struct ingenic_adc *adc;
+ struct resource *mem_base;
+ const struct ingenic_adc_soc_data *soc_data;
+ int 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);
+ adc->soc_data = soc_data;
+
+ mem_base = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ adc->base = devm_ioremap_resource(dev, mem_base);
+ if (IS_ERR(adc->base)) {
+ dev_err(dev, "Unable to ioremap mmio resource\n");
+ 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;
+ }
+
+ /* Put hardware in a known passive state. */
+ writeb(0x00, adc->base + JZ_ADC_REG_ENABLE);
+ writeb(0xff, adc->base + JZ_ADC_REG_CTRL);
+ 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->dev.parent = dev;
+ iio_dev->name = "jz-adc";
+ iio_dev->modes = INDIO_DIRECT_MODE;
+ iio_dev->channels = ingenic_channels;
+ iio_dev->num_channels = ARRAY_SIZE(ingenic_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;
+}
+
+#ifdef CONFIG_OF
+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, },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ingenic_adc_of_match);
+#endif
+
+static struct platform_driver ingenic_adc_driver = {
+ .driver = {
+ .name = "ingenic-adc",
+ .of_match_table = of_match_ptr(ingenic_adc_of_match),
+ },
+ .probe = ingenic_adc_probe,
+};
+module_platform_driver(ingenic_adc_driver);
--
2.20.1
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