On 04/22/2016 03:52 PM, Harald Geyer wrote:
> The hardware has two current sources ISRC0 and ISRC1 to allow measuring
> resistors without additional circuitry. This commit makes them available
> as regulators.
>
> Tested on an imx233-olinuxino board.
>
> Signed-off-by: Harald Geyer <harald@xxxxxxxxx>
> ---
> The current regulator API doesn't fit this type of device very well: Typically
> consumers will want to set a defined current, ie. min_uA == max_uA, but they
> can't without help from configuration data, because the valid values aren't
> reported by the API for current regulators. I have been thinking about
> extending the API, but currently AFAIK no such consumers exist and most
> users, like myself, will force the regulator to a defined value in
> devicetree anyway.
I am tempted to block this patch and ask you to properly split the
mxs-lradc driver into MFD with touchscreen and IIO part and only then
add the regulator bits. The lradc is becoming a katamari of ad-hoc
misplaced functionality.
> .../bindings/staging/iio/adc/mxs-lradc.txt | 29 ++++
> drivers/iio/adc/Kconfig | 1 +
> drivers/iio/adc/mxs-lradc.c | 152 +++++++++++++++++++++
> 3 files changed, 182 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt b/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
> index 555fb11..983952c 100644
> --- a/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
> +++ b/Documentation/devicetree/bindings/staging/iio/adc/mxs-lradc.txt
> @@ -19,6 +19,15 @@ Optional properties:
> - fsl,settling: delay between plate switch to next sample. Allowed value is
> 1 ... 2047. It counts at 2 kHz and its default is
> 10 (= 5 ms)
> +- ISRC0: A node describing the regulator of internal current source 0
> +- ISRC1: A node describing the regulator of internal current source 1
> +
> +Required properties for the ISRCx sub-nodes:
> +- regulator-max-microamp: See standard regulator binding documentation.
> + Valid values are from 0 to 300 in steps of 20.
> +
> +Optional properties for the ISRCx sub-nodes:
> +Any standard regulator properties that apply to current regulators.
>
> Example for i.MX23 SoC:
>
> @@ -31,6 +40,16 @@ Example for i.MX23 SoC:
> fsl,ave-ctrl = <4>;
> fsl,ave-delay = <2>;
> fsl,settling = <10>;
> +
> + isrc_lradc0: ISRC0 {
> + regulator-max-microamp = <300>;
> + };
> +
> + isrc_lradc1: ISRC1 {
> + regulator-max-microamp = <120>;
> + regulator-min-microamp = <120>;
> + regulator-always-on;
> + };
> };
>
> Example for i.MX28 SoC:
> @@ -44,4 +63,14 @@ Example for i.MX28 SoC:
> fsl,ave-ctrl = <4>;
> fsl,ave-delay = <2>;
> fsl,settling = <10>;
> +
> + isrc_lradc0: ISRC0 {
> + regulator-max-microamp = <300>;
> + };
> +
> + isrc_lradc6: ISRC1 {
> + regulator-max-microamp = <120>;
> + regulator-min-microamp = <120>;
> + regulator-always-on;
> + };
> };
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 5937030..1968d1c 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -319,6 +319,7 @@ config MXS_LRADC
> tristate "Freescale i.MX23/i.MX28 LRADC"
> depends on (ARCH_MXS || COMPILE_TEST) && HAS_IOMEM
> depends on INPUT
> + depends on REGULATOR
> select STMP_DEVICE
> select IIO_BUFFER
> select IIO_TRIGGERED_BUFFER
> diff --git a/drivers/iio/adc/mxs-lradc.c b/drivers/iio/adc/mxs-lradc.c
> index 33051b8..f22f339 100644
> --- a/drivers/iio/adc/mxs-lradc.c
> +++ b/drivers/iio/adc/mxs-lradc.c
> @@ -40,6 +40,10 @@
> #include <linux/iio/triggered_buffer.h>
> #include <linux/iio/sysfs.h>
>
> +#include <linux/regulator/driver.h>
> +#include <linux/regulator/machine.h>
> +#include <linux/regulator/of_regulator.h>
> +
> #define DRIVER_NAME "mxs-lradc"
>
> #define LRADC_MAX_DELAY_CHANS 4
> @@ -261,6 +265,9 @@ struct mxs_lradc {
> unsigned over_sample_delay;
> /* time in clocks to wait after the plates where switched */
> unsigned settling_delay;
> +
> + struct regulator_desc isrc0;
> + struct regulator_desc isrc1;
> };
>
> #define LRADC_CTRL0 0x00
> @@ -305,6 +312,11 @@ struct mxs_lradc {
> #define LRADC_CTRL2 0x20
> #define LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET 24
> #define LRADC_CTRL2_TEMPSENSE_PWD BIT(15)
> +#define LRADC_CTRL2_TEMP_SENSOR_IENABLE1 BIT(9)
> +#define LRADC_CTRL2_TEMP_SENSOR_IENABLE0 BIT(8)
> +#define LRADC_CTRL2_TEMP_ISRC1_OFFSET 4
> +#define LRADC_CTRL2_TEMP_ISRC0_OFFSET 0
> +#define LRADC_CTRL2_TEMP_ISRC_MASK 0x0f
>
> #define LRADC_STATUS 0x40
> #define LRADC_STATUS_TOUCH_DETECT_RAW BIT(0)
> @@ -1383,6 +1395,109 @@ static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
> .validate_scan_mask = &mxs_lradc_validate_scan_mask,
> };
>
> +static int mxs_lradc_regulator_is_enabled(struct regulator_dev *dev)
> +{
> + struct mxs_lradc *lradc = rdev_get_drvdata(dev);
> + int reg = readl(lradc->base + LRADC_CTRL2);
> +
> + if (dev->desc == &lradc->isrc0)
> + return reg & LRADC_CTRL2_TEMP_SENSOR_IENABLE0;
> + else if (dev->desc == &lradc->isrc1)
> + return reg & LRADC_CTRL2_TEMP_SENSOR_IENABLE1;
> +
> + /* This should never happen */
> + return -ENODEV;
> +}
> +
> +#define LRADC_REGVALUE2uA(regval, offset) \
> + (20 * ((regval >> offset) & LRADC_CTRL2_TEMP_ISRC_MASK))
> +
> +static int mxs_lradc_regulator_get_current_limit(struct regulator_dev *dev)
> +{
> + struct mxs_lradc *lradc = rdev_get_drvdata(dev);
> + int reg = readl(lradc->base + LRADC_CTRL2);
> +
> + if (dev->desc == &lradc->isrc0)
> + return LRADC_REGVALUE2uA(reg, LRADC_CTRL2_TEMP_ISRC0_OFFSET);
> + else if (dev->desc == &lradc->isrc1)
> + return LRADC_REGVALUE2uA(reg, LRADC_CTRL2_TEMP_ISRC1_OFFSET);
> +
> + /* This should never happen */
> + return -ENODEV;
> +}
> +
> +static int mxs_lradc_regulator_enable(struct regulator_dev *dev)
> +{
> + struct mxs_lradc *lradc = rdev_get_drvdata(dev);
> +
> + if (dev->desc == &lradc->isrc0)
> + mxs_lradc_reg_set(lradc, LRADC_CTRL2_TEMP_SENSOR_IENABLE0,
> + LRADC_CTRL2);
> + else if (dev->desc == &lradc->isrc1)
> + mxs_lradc_reg_set(lradc, LRADC_CTRL2_TEMP_SENSOR_IENABLE1,
> + LRADC_CTRL2);
> + else
> + /* This should never happen */
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static int mxs_lradc_regulator_disable(struct regulator_dev *dev)
> +{
> + struct mxs_lradc *lradc = rdev_get_drvdata(dev);
> +
> + if (dev->desc == &lradc->isrc0)
> + mxs_lradc_reg_clear(lradc, LRADC_CTRL2_TEMP_SENSOR_IENABLE0,
> + LRADC_CTRL2);
> + else if (dev->desc == &lradc->isrc1)
> + mxs_lradc_reg_clear(lradc, LRADC_CTRL2_TEMP_SENSOR_IENABLE1,
> + LRADC_CTRL2);
> + else
> + /* This should never happen */
> + return -ENODEV;
> +
> + return 0;
> +}
> +
> +static int mxs_lradc_regulator_set_current_limit(struct regulator_dev *dev,
> + int min_uA, int max_uA)
> +{
> + struct mxs_lradc *lradc = rdev_get_drvdata(dev);
> + int offset, value;
> +
> + if (dev->desc == &lradc->isrc0)
> + offset = LRADC_CTRL2_TEMP_ISRC0_OFFSET;
> + else if (dev->desc == &lradc->isrc1)
> + offset = LRADC_CTRL2_TEMP_ISRC1_OFFSET;
> + else
> + /* This should never happen */
> + return -ENODEV;
> +
> + value = min_uA / 20;
> + if (min_uA % 20)
> + value++;
> + if (value * 20 > max_uA)
> + return -EINVAL;
> + if (value & ~LRADC_CTRL2_TEMP_ISRC_MASK)
> + /* This should never happen */
> + return -EPERM;
> +
> + mxs_lradc_reg_clear(lradc, LRADC_CTRL2_TEMP_ISRC_MASK << offset,
> + LRADC_CTRL2);
> + mxs_lradc_reg_set(lradc, value << offset, LRADC_CTRL2);
> +
> + return 0;
> +}
> +
> +static struct regulator_ops mxs_lradc_regulator_current_ops = {
> + .enable = mxs_lradc_regulator_enable,
> + .is_enabled = mxs_lradc_regulator_is_enabled,
> + .disable = mxs_lradc_regulator_disable,
> + .get_current_limit = mxs_lradc_regulator_get_current_limit,
> + .set_current_limit = mxs_lradc_regulator_set_current_limit,
> +};
> +
> /*
> * Driver initialization
> */
> @@ -1519,6 +1634,10 @@ static void mxs_lradc_hw_stop(struct mxs_lradc *lradc)
>
> for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++)
> mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(i));
> +
> + mxs_lradc_reg_clear(lradc, LRADC_CTRL2_TEMP_SENSOR_IENABLE0 |
> + LRADC_CTRL2_TEMP_SENSOR_IENABLE1,
> + LRADC_CTRL2);
> }
>
> static const struct of_device_id mxs_lradc_dt_ids[] = {
> @@ -1592,6 +1711,32 @@ static int mxs_lradc_probe_touchscreen(struct mxs_lradc *lradc,
> return 0;
> }
>
> +static void mxs_lradc_reg_helper(struct device_node *np, const char *name,
> + struct regulator_config *conf,
> + struct regulator_desc *desc)
> +{
> + struct regulator_dev *ret;
> +
> + conf->of_node = of_get_child_by_name(np, name);
> + if (!conf->of_node)
> + return;
> +
> + desc->name = name;
> + desc->owner = THIS_MODULE;
> + desc->type = REGULATOR_CURRENT;
> + desc->ops = &mxs_lradc_regulator_current_ops;
> +
> + conf->init_data = of_get_regulator_init_data(conf->dev, conf->of_node,
> + desc);
> + ret = devm_regulator_register(conf->dev, desc, conf);
> + if (IS_ERR(ret))
> + /* Just pretend the regulator isn't there */
> + dev_err(conf->dev, "Failed to register regulator %s: %ld\n",
> + desc->name, PTR_ERR(ret));
> +
> + of_node_put(conf->of_node);
> +}
> +
> static int mxs_lradc_probe(struct platform_device *pdev)
> {
> const struct of_device_id *of_id =
> @@ -1603,6 +1748,7 @@ static int mxs_lradc_probe(struct platform_device *pdev)
> struct mxs_lradc *lradc;
> struct iio_dev *iio;
> struct resource *iores;
> + struct regulator_config regconf;
> int ret = 0, touch_ret;
> int i, s;
> u64 scale_uv;
> @@ -1727,6 +1873,12 @@ static int mxs_lradc_probe(struct platform_device *pdev)
> goto err_ts;
> }
>
> + /* Setup regulator devices for current source. */
> + regconf.dev = dev;
> + regconf.driver_data = lradc;
> + mxs_lradc_reg_helper(node, "ISRC0", ®conf, &lradc->isrc0);
> + mxs_lradc_reg_helper(node, "ISRC1", ®conf, &lradc->isrc1);
> +
> return 0;
>
> err_ts:
>
--
Best regards,
Marek Vasut
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