This is a copy from kernel.

Signed-off-by: Kever Yang kever.yang@rock-chips.com ---

Changes in v3: None Changes in v2: None

doc/device-tree-bindings/pwm/pwm.txt | 69 ++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 doc/device-tree-bindings/pwm/pwm.txt

diff --git a/doc/device-tree-bindings/pwm/pwm.txt b/doc/device-tree-bindings/pwm/pwm.txt new file mode 100644 index 0000000..8556263 --- /dev/null +++ b/doc/device-tree-bindings/pwm/pwm.txt @@ -0,0 +1,69 @@ +Specifying PWM information for devices +====================================== + +1) PWM user nodes +----------------- + +PWM users should specify a list of PWM devices that they want to use +with a property containing a 'pwm-list': + + pwm-list ::= <single-pwm> [pwm-list] + single-pwm ::= <pwm-phandle> <pwm-specifier> + pwm-phandle : phandle to PWM controller node + pwm-specifier : array of #pwm-cells specifying the given PWM + (controller specific) + +PWM properties should be named "pwms". The exact meaning of each pwms +property must be documented in the device tree binding for each device. +An optional property "pwm-names" may contain a list of strings to label +each of the PWM devices listed in the "pwms" property. If no "pwm-names" +property is given, the name of the user node will be used as fallback. + +Drivers for devices that use more than a single PWM device can use the +"pwm-names" property to map the name of the PWM device requested by the +pwm_get() call to an index into the list given by the "pwms" property. + +The following example could be used to describe a PWM-based backlight +device: + + pwm: pwm { + #pwm-cells = <2>; + }; + + [...] + + bl: backlight { + pwms = <&pwm 0 5000000>; + pwm-names = "backlight"; + }; + +Note that in the example above, specifying the "pwm-names" is redundant +because the name "backlight" would be used as fallback anyway. + +pwm-specifier typically encodes the chip-relative PWM number and the PWM +period in nanoseconds. + +Optionally, the pwm-specifier can encode a number of flags (defined in +<dt-bindings/pwm/pwm.h>) in a third cell: +- PWM_POLARITY_INVERTED: invert the PWM signal polarity + +Example with optional PWM specifier for inverse polarity + + bl: backlight { + pwms = <&pwm 0 5000000 PWM_POLARITY_INVERTED>; + pwm-names = "backlight"; + }; + +2) PWM controller nodes +----------------------- + +PWM controller nodes must specify the number of cells used for the +specifier using the '#pwm-cells' property. + +An example PWM controller might look like this: + + pwm: pwm@7000a000 { + compatible = "nvidia,tegra20-pwm"; + reg = <0x7000a000 0x100>; + #pwm-cells = <2>; + };

Add test case for new interface set_invert().

Signed-off-by: Kever Yang kever.yang@rock-chips.com ---

Changes in v3: None Changes in v2: None

drivers/pwm/sandbox_pwm.c | 16 ++++++++++++++++ test/dm/pwm.c | 1 + 2 files changed, 17 insertions(+)

diff --git a/drivers/pwm/sandbox_pwm.c b/drivers/pwm/sandbox_pwm.c index c2ce974..50a35d9 100644 --- a/drivers/pwm/sandbox_pwm.c +++ b/drivers/pwm/sandbox_pwm.c @@ -21,6 +21,7 @@ struct sandbox_pwm_chan { uint period_ns; uint duty_ns; bool enable; + bool polarity; };

struct sandbox_pwm_priv { @@ -56,9 +57,24 @@ static int sandbox_pwm_set_enable(struct udevice *dev, uint channel, return 0; }

+static int sandbox_pwm_set_invert(struct udevice *dev, uint channel, + bool polarity); +{ + struct sandbox_pwm_priv *priv = dev_get_priv(dev); + struct sandbox_pwm_chan *chan; + + if (channel >= NUM_CHANNELS) + return -ENOSPC; + chan = &priv->chan[channel]; + chan->polarity = polarity; + + return 0; +} + static const struct pwm_ops sandbox_pwm_ops = { .set_config = sandbox_pwm_set_config, .set_enable = sandbox_pwm_set_enable, + .set_invert = sandbox_pwm_set_invert, };

static const struct udevice_id sandbox_pwm_ids[] = { diff --git a/test/dm/pwm.c b/test/dm/pwm.c index 7bdc75a..f1e38c7 100644 --- a/test/dm/pwm.c +++ b/test/dm/pwm.c @@ -23,6 +23,7 @@ static int dm_test_pwm_base(struct unit_test_state *uts) ut_assertok(pwm_set_enable(dev, 1, true)); ut_assertok(pwm_set_enable(dev, 2, true)); ut_asserteq(-ENOSPC, pwm_set_enable(dev, 3, true)); + ut_assertok(pwm_set_invert(dev, 0, true));

ut_assertok(uclass_get_device(UCLASS_PWM, 1, &dev)); ut_asserteq(-ENODEV, uclass_get_device(UCLASS_PWM, 2, &dev));

Hi Kever,

On 19 April 2017 at 03:37, Kever Yang kever.yang@rock-chips.com wrote:

The latest kernel PWM drivers enable the polarity settings. When system run from U-Boot to kerenl, if there are differences in polarity set or duty cycle, the PMW will re-init: close -> set polarity and duty cycle -> enable the PWM. The power supply controled by pwm regulator may have voltage shaking, which lead to the system not stable.

Signed-off-by: Elaine Zhang zhangqing@rock-chips.com Signed-off-by: Kever Yang kever.yang@rock-chips.com

---

Changes in v3:

• use bool type for polarity
• add sambox test

sandbox

Also this is actually in another patch

Please split this inot the uclass/header change and the rockchip change. The latter should have a rockchip: tag.

For both when you resend you can add:

Acked-by: Simon Glass sjg@chromium.org

Changes in v2:

• use pwm_set_invert() instead of pwm_set_init()
• add comment for polarity

drivers/power/regulator/pwm_regulator.c | 16 ++++++++++++++-- drivers/pwm/pwm-uclass.c | 10 ++++++++++ drivers/pwm/rk_pwm.c | 17 ++++++++++++++++- include/pwm.h | 19 +++++++++++++++++++ 4 files changed, 59 insertions(+), 3 deletions(-)

diff --git a/drivers/power/regulator/pwm_regulator.c b/drivers/power/regulator/pwm_regulator.c index 4875238..a6c9fcc 100644 --- a/drivers/power/regulator/pwm_regulator.c +++ b/drivers/power/regulator/pwm_regulator.c @@ -24,6 +24,12 @@ struct pwm_regulator_info { int pwm_id; /* the period of one PWM cycle */ int period_ns;

•   /*
  

•    * the polarity of one PWM
  

•    * 0: normal polarity
  

•    * 1: inverted polarity
  

use false, true

•    */
  

•   bool polarity;
    struct udevice *pwm;
    /* initialize voltage of regulator */
    unsigned int init_voltage;
  

@@ -49,7 +55,7 @@ static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV) int max_uV = priv->max_voltage; int diff = max_uV - min_uV;

•   return 100 - (((req_uV * 100) - (min_uV * 100)) / diff);
  

•   return ((req_uV * 100) - (min_uV * 100)) / diff;
  

}

static int pwm_regulator_get_voltage(struct udevice *dev) @@ -67,6 +73,12 @@ static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt)

    duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt);

•   ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity);
  

•   if (ret) {
  

•           dev_err(dev, "Failed to init PWM\n");
  

•           return ret;
  

•   }
  

•   ret = pwm_set_config(priv->pwm, priv->pwm_id,
                    (priv->period_ns / 100) * duty_cycle, priv->period_ns);
    if (ret) {
  

@@ -97,9 +109,9 @@ static int pwm_regulator_ofdata_to_platdata(struct udevice *dev) debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret); return ret; }

•   /* TODO: pwm_id here from device tree if needed */
  
    priv->period_ns = args.args[1];
  

•   priv->polarity = args.args[2];
  
    priv->init_voltage = fdtdec_get_int(blob, node,
                    "regulator-init-microvolt", -1);
  

diff --git a/drivers/pwm/pwm-uclass.c b/drivers/pwm/pwm-uclass.c index c2200af..69051fe 100644 --- a/drivers/pwm/pwm-uclass.c +++ b/drivers/pwm/pwm-uclass.c @@ -9,6 +9,16 @@ #include <dm.h> #include <pwm.h>

+int pwm_set_invert(struct udevice *dev, uint channel, bool polarity) +{

•   struct pwm_ops *ops = pwm_get_ops(dev);
  

•   if (!ops->set_invert)
  

•           return -ENOSYS;
  

•   return ops->set_invert(dev, channel, polarity);
  

+}

int pwm_set_config(struct udevice *dev, uint channel, uint period_ns, uint duty_ns) { diff --git a/drivers/pwm/rk_pwm.c b/drivers/pwm/rk_pwm.c index 9254f5b..f3b2f76 100644 --- a/drivers/pwm/rk_pwm.c +++ b/drivers/pwm/rk_pwm.c @@ -21,8 +21,22 @@ DECLARE_GLOBAL_DATA_PTR; struct rk_pwm_priv { struct rk3288_pwm *regs; ulong freq;

•   uint enable_conf;
  

};

+static int rk_pwm_set_invert(struct udevice *dev, uint channel, bool polarity) +{

•   struct rk_pwm_priv *priv = dev_get_priv(dev);
  

•   debug("%s: polarity=%u\n", __func__, polarity);
  

•   if (polarity)
  

•           priv->enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSTIVE;
  

•   else
  

•           priv->enable_conf |= PWM_DUTY_POSTIVE | PWM_INACTIVE_NEGATIVE;
  

•   return 0;
  

+}

static int rk_pwm_set_config(struct udevice *dev, uint channel, uint period_ns, uint duty_ns) { @@ -32,7 +46,7 @@ static int rk_pwm_set_config(struct udevice *dev, uint channel, uint period_ns,

    debug("%s: period_ns=%u, duty_ns=%u\n", __func__, period_ns, duty_ns);
    writel(PWM_SEL_SRC_CLK | PWM_OUTPUT_LEFT | PWM_LP_DISABLE |

•           PWM_CONTINUOUS | PWM_DUTY_POSTIVE | PWM_INACTIVE_POSTIVE |
  

•           PWM_CONTINUOUS | priv->enable_conf |
            RK_PWM_DISABLE,
            &regs->ctrl);
  
  

@@ -83,6 +97,7 @@ static int rk_pwm_probe(struct udevice *dev) }

static const struct pwm_ops rk_pwm_ops = {

•   .set_invert     = rk_pwm_set_invert,
    .set_config     = rk_pwm_set_config,
    .set_enable     = rk_pwm_set_enable,
  

}; diff --git a/include/pwm.h b/include/pwm.h index 851915e..ebee227 100644 --- a/include/pwm.h +++ b/include/pwm.h @@ -34,6 +34,15 @@ struct pwm_ops { * @return 0 if OK, -ve on error */ int (*set_enable)(struct udevice *dev, uint channel, bool enable);

•   /**
  

•    * set_invert() - Set the PWM invert
  

•    *
  

•    * @dev:        PWM device to update
  

•    * @channel:    PWM channel to update
  

•    * @polarity:   true to invert, false to keep normal polarity
  

•    * @return 0 if OK, -ve on error
  

•    */
  

•   int (*set_invert)(struct udevice *dev, uint channel, bool polarity);
  

};

#define pwm_get_ops(dev) ((struct pwm_ops *)(dev)->driver->ops) @@ -60,6 +69,16 @@ int pwm_set_config(struct udevice *dev, uint channel, uint period_ns, */ int pwm_set_enable(struct udevice *dev, uint channel, bool enable);

+/**

• • pwm_set_invert() - Set pwm default polarity
• • @dev: PWM device to update
• • @channel: PWM channel to update
• • @polarity: true to invert, false to keep normal polarity
• • @return 0 if OK, -ve on error
• */

+int pwm_set_invert(struct udevice *dev, uint channel, bool polarity);

/* Legacy interface */ #ifndef CONFIG_DM_PWM int pwm_init (int pwm_id, int div, int invert); -- 1.9.1

Regards, Simon