ARM: s3c: Use pwm_get() in favour of pwm_request() in RX1950

pwm_request() is deprecated because (among others) it depends on a global
numbering of PWM devices. So register a pwm_lookup to pick the right PWM
device (identified by provider and its local id) and use pwm_get().

Before this patch the PWM #1 was used. This is provided by the
samsung-pwm device which is the only PWM provider on this machine. The
local offset is 1, see also commit c107fe904a10 ("ARM: S3C24XX: Use PWM
lookup table for mach-rx1950") with a similar conversion for PWM #0.

As a follow up specify the period only once and symmetrically use pwm_put()
instead of pwm_free() to drop the reference.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210326090641.122436-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>

diff --git a/arch/arm/mach-s3c/mach-rx1950.c b/arch/arm/mach-s3c/mach-rx1950.c
index 6e19add158a987e445925c59346d3c2ca4d3e10a..a3f46aa61c45b5f7347429c4d2d14c19746ef17f 100644 (file)
--- a/arch/arm/mach-s3c/mach-rx1950.c
+++ b/arch/arm/mach-s3c/mach-rx1950.c
@@ -384,6 +384,8 @@ static struct s3c2410fb_mach_info rx1950_lcd_cfg = {
 static struct pwm_lookup rx1950_pwm_lookup[] = {
        PWM_LOOKUP("samsung-pwm", 0, "pwm-backlight.0", NULL, 48000,
                   PWM_POLARITY_NORMAL),
+       PWM_LOOKUP("samsung-pwm", 1, "pwm-backlight.0", "RX1950 LCD", LCD_PWM_PERIOD,
+                  PWM_POLARITY_NORMAL),
 };
 
 static struct pwm_device *lcd_pwm;
@@ -498,19 +500,18 @@ static void rx1950_bl_power(int enable)
 static int rx1950_backlight_init(struct device *dev)
 {
        WARN_ON(gpio_request(S3C2410_GPB(0), "Backlight"));
-       lcd_pwm = pwm_request(1, "RX1950 LCD");
+       lcd_pwm = pwm_get(dev, "RX1950 LCD");
        if (IS_ERR(lcd_pwm)) {
                dev_err(dev, "Unable to request PWM for LCD power!\n");
                return PTR_ERR(lcd_pwm);
        }
 
        /*
-        * This is only required to initialize .polarity; all other values are
-        * fixed in this driver.
+        * Call pwm_init_state to initialize .polarity and .period. The other
+        * values are fixed in this driver.
         */
        pwm_init_state(lcd_pwm, &lcd_pwm_state);
 
-       lcd_pwm_state.period = LCD_PWM_PERIOD;
        lcd_pwm_state.duty_cycle = LCD_PWM_DUTY;
 
        rx1950_lcd_power(1);
@@ -524,7 +525,7 @@ static void rx1950_backlight_exit(struct device *dev)
        rx1950_bl_power(0);
        rx1950_lcd_power(0);
 
-       pwm_free(lcd_pwm);
+       pwm_put(lcd_pwm);
        gpio_free(S3C2410_GPB(0));
 }