Merge branch 'for-3.6' of git://gitorious.org/linux-pwm/linux-pwm

Pull PWM subsystem from Thierry Reding:
 "The new PWM subsystem aims at collecting all implementations of the
  legacy PWM API and to eventually replace it completely.

  The subsystem has been in development for over half a year now and
  many drivers have already been converted.  It has been in linux-next
  for a couple of weeks and there have been no major issues so I think
  it is ready for inclusion in your tree."

Arnd Bergmann <arnd@arndb.de>:
 "Very much Ack on the new subsystem.  It uses the interface
  declarations as the previously separate pwm drivers, so nothing
  changes for now in the drivers using it, although it enables us to
  change those more easily in the future if we want to.

  This work is also one of the missing pieces that are required to
  eventually build ARM kernels for multiple platforms, which is
  currently prohibited (amongs other things) by the fact that you cannot
  have more than one driver exporting the pwm functions."

Tested-and-acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Philip, Avinash <avinashphilip@ti.com> # TI's AM33xx platforms
Acked-By: Alexandre Pereira da Silva <aletes.xgr@gmail.com> # LPC32XX
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Sachin Kamat <sachin.kamat@linaro.org>

Fix up trivial conflicts with other cleanups and DT updates.

* 'for-3.6' of git://gitorious.org/linux-pwm/linux-pwm: (36 commits)
  pwm: pwm-tiehrpwm: PWM driver support for EHRPWM
  pwm: pwm-tiecap: PWM driver support for ECAP APWM
  pwm: fix used-uninitialized warning in pwm_get()
  pwm: add lpc32xx PWM support
  pwm_backlight: pass correct brightness to callback
  pwm: Use pr_* functions in pwm-samsung.c file
  pwm: Convert pwm-samsung to use devm_* APIs
  pwm: Convert pwm-tegra to use devm_clk_get()
  pwm: pwm-mxs: Return proper error if pwmchip_remove() fails
  pwm: pwm-bfin: Return proper error if pwmchip_remove() fails
  pwm: pxa: Propagate pwmchip_remove() error
  pwm: Convert pwm-pxa to use devm_* APIs
  pwm: Convert pwm-vt8500 to use devm_* APIs
  pwm: Convert pwm-imx to use devm_* APIs
  pwm: Conflict with legacy PWM API
  pwm: pwm-mxs: add pinctrl support
  pwm: pwm-mxs: use devm_* managed functions
  pwm: pwm-mxs: use global reset function stmp_reset_block
  pwm: pwm-mxs: encode soc name in compatible string
  pwm: Take over maintainership of the PWM subsystem
  ...

2 files changed, 137 insertions, 24 deletions

diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
index 2979292650d..cf282763a8d 100644
--- a/drivers/video/backlight/Kconfig
+++ b/drivers/video/backlight/Kconfig
@@ -245,7 +245,7 @@ config BACKLIGHT_CARILLO_RANCH
 
 config BACKLIGHT_PWM
         tristate "Generic PWM based Backlight Driver"
-        depends on HAVE_PWM
+        depends on PWM
         help
           If you have a LCD backlight adjustable by PWM, say Y to enable
           this driver.
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 342b7d7cbb6..995f0164c9b 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -26,11 +26,13 @@ struct pwm_bl_data {
         struct device           *dev;
         unsigned int            period;
         unsigned int            lth_brightness;
+        unsigned int            *levels;
         int                     (*notify)(struct device *,
                                           int brightness);
         void                    (*notify_after)(struct device *,
                                         int brightness);
         int                     (*check_fb)(struct device *, struct fb_info *);
+        void                    (*exit)(struct device *);
 };
 
 static int pwm_backlight_update_status(struct backlight_device *bl)
@@ -52,9 +54,18 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
                 pwm_config(pb->pwm, 0, pb->period);
                 pwm_disable(pb->pwm);
         } else {
-                brightness = pb->lth_brightness +
-                        (brightness * (pb->period - pb->lth_brightness) / max);
-                pwm_config(pb->pwm, brightness, pb->period);
+                int duty_cycle;
+
+                if (pb->levels) {
+                        duty_cycle = pb->levels[brightness];
+                        max = pb->levels[max];
+                } else {
+                        duty_cycle = brightness;
+                }
+
+                duty_cycle = pb->lth_brightness +
+                     (duty_cycle * (pb->period - pb->lth_brightness) / max);
+                pwm_config(pb->pwm, duty_cycle, pb->period);
                 pwm_enable(pb->pwm);
         }
 
@@ -83,17 +94,98 @@ static const struct backlight_ops pwm_backlight_ops = {
         .check_fb       = pwm_backlight_check_fb,
 };
 
+#ifdef CONFIG_OF
+static int pwm_backlight_parse_dt(struct device *dev,
+                                  struct platform_pwm_backlight_data *data)
+{
+        struct device_node *node = dev->of_node;
+        struct property *prop;
+        int length;
+        u32 value;
+        int ret;
+
+        if (!node)
+                return -ENODEV;
+
+        memset(data, 0, sizeof(*data));
+
+        /* determine the number of brightness levels */
+        prop = of_find_property(node, "brightness-levels", &length);
+        if (!prop)
+                return -EINVAL;
+
+        data->max_brightness = length / sizeof(u32);
+
+        /* read brightness levels from DT property */
+        if (data->max_brightness > 0) {
+                size_t size = sizeof(*data->levels) * data->max_brightness;
+
+                data->levels = devm_kzalloc(dev, size, GFP_KERNEL);
+                if (!data->levels)
+                        return -ENOMEM;
+
+                ret = of_property_read_u32_array(node, "brightness-levels",
+                                                 data->levels,
+                                                 data->max_brightness);
+                if (ret < 0)
+                        return ret;
+
+                ret = of_property_read_u32(node, "default-brightness-level",
+                                           &value);
+                if (ret < 0)
+                        return ret;
+
+                if (value >= data->max_brightness) {
+                        dev_warn(dev, "invalid default brightness level: %u, using %u\n",
+                                 value, data->max_brightness - 1);
+                        value = data->max_brightness - 1;
+                }
+
+                data->dft_brightness = value;
+                data->max_brightness--;
+        }
+
+        /*
+         * TODO: Most users of this driver use a number of GPIOs to control
+         *       backlight power. Support for specifying these needs to be
+         *       added.
+         */
+
+        return 0;
+}
+
+static struct of_device_id pwm_backlight_of_match[] = {
+        { .compatible = "pwm-backlight" },
+        { }
+};
+
+MODULE_DEVICE_TABLE(of, pwm_backlight_of_match);
+#else
+static int pwm_backlight_parse_dt(struct device *dev,
+                                  struct platform_pwm_backlight_data *data)
+{
+        return -ENODEV;
+}
+#endif
+
 static int pwm_backlight_probe(struct platform_device *pdev)
 {
-        struct backlight_properties props;
         struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
+        struct platform_pwm_backlight_data defdata;
+        struct backlight_properties props;
         struct backlight_device *bl;
         struct pwm_bl_data *pb;
+        unsigned int max;
         int ret;
 
         if (!data) {
-                dev_err(&pdev->dev, "failed to find platform data\n");
-                return -EINVAL;
+                ret = pwm_backlight_parse_dt(&pdev->dev, &defdata);
+                if (ret < 0) {
+                        dev_err(&pdev->dev, "failed to find platform data\n");
+                        return ret;
+                }
+
+                data = &defdata;
         }
 
         if (data->init) {
@@ -109,21 +201,42 @@ static int pwm_backlight_probe(struct platform_device *pdev)
                 goto err_alloc;
         }
 
-        pb->period = data->pwm_period_ns;
+        if (data->levels) {
+                max = data->levels[data->max_brightness];
+                pb->levels = data->levels;
+        } else
+                max = data->max_brightness;
+
         pb->notify = data->notify;
         pb->notify_after = data->notify_after;
         pb->check_fb = data->check_fb;
-        pb->lth_brightness = data->lth_brightness *
-                (data->pwm_period_ns / data->max_brightness);
+        pb->exit = data->exit;
         pb->dev = &pdev->dev;
 
-        pb->pwm = pwm_request(data->pwm_id, "backlight");
+        pb->pwm = pwm_get(&pdev->dev, NULL);
         if (IS_ERR(pb->pwm)) {
-                dev_err(&pdev->dev, "unable to request PWM for backlight\n");
-                ret = PTR_ERR(pb->pwm);
-                goto err_alloc;
-        } else
-                dev_dbg(&pdev->dev, "got pwm for backlight\n");
+                dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
+
+                pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
+                if (IS_ERR(pb->pwm)) {
+                        dev_err(&pdev->dev, "unable to request legacy PWM\n");
+                        ret = PTR_ERR(pb->pwm);
+                        goto err_alloc;
+                }
+        }
+
+        dev_dbg(&pdev->dev, "got pwm for backlight\n");
+
+        /*
+         * The DT case will set the pwm_period_ns field to 0 and store the
+         * period, parsed from the DT, in the PWM device. For the non-DT case,
+         * set the period from platform data.
+         */
+        if (data->pwm_period_ns > 0)
+                pwm_set_period(pb->pwm, data->pwm_period_ns);
+
+        pb->period = pwm_get_period(pb->pwm);
+        pb->lth_brightness = data->lth_brightness * (pb->period / max);
 
         memset(&props, 0, sizeof(struct backlight_properties));
         props.type = BACKLIGHT_RAW;
@@ -143,7 +256,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
         return 0;
 
 err_bl:
-        pwm_free(pb->pwm);
+        pwm_put(pb->pwm);
 err_alloc:
         if (data->exit)
                 data->exit(&pdev->dev);
@@ -152,16 +265,15 @@ err_alloc:
 
 static int pwm_backlight_remove(struct platform_device *pdev)
 {
-        struct platform_pwm_backlight_data *data = pdev->dev.platform_data;
         struct backlight_device *bl = platform_get_drvdata(pdev);
         struct pwm_bl_data *pb = dev_get_drvdata(&bl->dev);
 
         backlight_device_unregister(bl);
         pwm_config(pb->pwm, 0, pb->period);
         pwm_disable(pb->pwm);
-        pwm_free(pb->pwm);
-        if (data->exit)
-                data->exit(&pdev->dev);
+        pwm_put(pb->pwm);
+        if (pb->exit)
+                pb->exit(&pdev->dev);
         return 0;
 }
 
@@ -195,11 +307,12 @@ static SIMPLE_DEV_PM_OPS(pwm_backlight_pm_ops, pwm_backlight_suspend,
 
 static struct platform_driver pwm_backlight_driver = {
         .driver         = {
-                .name   = "pwm-backlight",
-                .owner  = THIS_MODULE,
+                .name           = "pwm-backlight",
+                .owner          = THIS_MODULE,
 #ifdef CONFIG_PM
-                .pm     = &pwm_backlight_pm_ops,
+                .pm             = &pwm_backlight_pm_ops,
 #endif
+                .of_match_table = of_match_ptr(pwm_backlight_of_match),
         },
         .probe          = pwm_backlight_probe,
         .remove         = pwm_backlight_remove,