HI
On Fri, Apr 22, 2016 at 5:50 PM, Marek Vasut <marex@xxxxxxx> wrote:
> 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.
I almost finished, I already split the driver into MFD, sorry for the delay.
Can this wait a little bit?
Thanks,
Ksenija
>> .../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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