pwm: i.MX: factor out SoC specific functions

To cleanup the code and to make it easier to support different
SoCs.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>

1 files changed, 83 insertions, 63 deletions

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index 2a0b35333972..8b7f01e0a100 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -46,81 +46,96 @@ struct imx_chip {
         void __iomem    *mmio_base;
 
         struct pwm_chip chip;
+
+        int (*config)(struct pwm_chip *chip,
+                struct pwm_device *pwm, int duty_ns, int period_ns);
 };
 
 #define to_imx_chip(chip)       container_of(chip, struct imx_chip, chip)
 
-static int imx_pwm_config(struct pwm_chip *chip,
+static int imx_pwm_config_v1(struct pwm_chip *chip,
                 struct pwm_device *pwm, int duty_ns, int period_ns)
 {
         struct imx_chip *imx = to_imx_chip(chip);
 
-        if (!(cpu_is_mx1() || cpu_is_mx21())) {
-                unsigned long long c;
-                unsigned long period_cycles, duty_cycles, prescale;
-                u32 cr;
-
-                c = clk_get_rate(imx->clk);
-                c = c * period_ns;
-                do_div(c, 1000000000);
-                period_cycles = c;
-
-                prescale = period_cycles / 0x10000 + 1;
-
-                period_cycles /= prescale;
-                c = (unsigned long long)period_cycles * duty_ns;
-                do_div(c, period_ns);
-                duty_cycles = c;
-
-                /*
-                 * according to imx pwm RM, the real period value should be
-                 * PERIOD value in PWMPR plus 2.
-                 */
-                if (period_cycles > 2)
-                        period_cycles -= 2;
-                else
-                        period_cycles = 0;
-
-                writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
-                writel(period_cycles, imx->mmio_base + MX3_PWMPR);
-
-                cr = MX3_PWMCR_PRESCALER(prescale) |
-                        MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
-                        MX3_PWMCR_DBGEN | MX3_PWMCR_EN;
-
-                if (cpu_is_mx25())
-                        cr |= MX3_PWMCR_CLKSRC_IPG;
-                else
-                        cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
-
-                writel(cr, imx->mmio_base + MX3_PWMCR);
-        } else if (cpu_is_mx1() || cpu_is_mx21()) {
-                /* The PWM subsystem allows for exact frequencies. However,
-                 * I cannot connect a scope on my device to the PWM line and
-                 * thus cannot provide the program the PWM controller
-                 * exactly. Instead, I'm relying on the fact that the
-                 * Bootloader (u-boot or WinCE+haret) has programmed the PWM
-                 * function group already. So I'll just modify the PWM sample
-                 * register to follow the ratio of duty_ns vs. period_ns
-                 * accordingly.
-                 *
-                 * This is good enough for programming the brightness of
-                 * the LCD backlight.
-                 *
-                 * The real implementation would divide PERCLK[0] first by
-                 * both the prescaler (/1 .. /128) and then by CLKSEL
-                 * (/2 .. /16).
-                 */
-                u32 max = readl(imx->mmio_base + MX1_PWMP);
-                u32 p = max * duty_ns / period_ns;
-                writel(max - p, imx->mmio_base + MX1_PWMS);
-        } else {
-                BUG();
-        }
+        /*
+         * The PWM subsystem allows for exact frequencies. However,
+         * I cannot connect a scope on my device to the PWM line and
+         * thus cannot provide the program the PWM controller
+         * exactly. Instead, I'm relying on the fact that the
+         * Bootloader (u-boot or WinCE+haret) has programmed the PWM
+         * function group already. So I'll just modify the PWM sample
+         * register to follow the ratio of duty_ns vs. period_ns
+         * accordingly.
+         *
+         * This is good enough for programming the brightness of
+         * the LCD backlight.
+         *
+         * The real implementation would divide PERCLK[0] first by
+         * both the prescaler (/1 .. /128) and then by CLKSEL
+         * (/2 .. /16).
+         */
+        u32 max = readl(imx->mmio_base + MX1_PWMP);
+        u32 p = max * duty_ns / period_ns;
+        writel(max - p, imx->mmio_base + MX1_PWMS);
+
+        return 0;
+}
+
+static int imx_pwm_config_v2(struct pwm_chip *chip,
+                struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+        struct imx_chip *imx = to_imx_chip(chip);
+        unsigned long long c;
+        unsigned long period_cycles, duty_cycles, prescale;
+        u32 cr;
+
+        c = clk_get_rate(imx->clk);
+        c = c * period_ns;
+        do_div(c, 1000000000);
+        period_cycles = c;
+
+        prescale = period_cycles / 0x10000 + 1;
+
+        period_cycles /= prescale;
+        c = (unsigned long long)period_cycles * duty_ns;
+        do_div(c, period_ns);
+        duty_cycles = c;
+
+        /*
+         * according to imx pwm RM, the real period value should be
+         * PERIOD value in PWMPR plus 2.
+         */
+        if (period_cycles > 2)
+                period_cycles -= 2;
+        else
+                period_cycles = 0;
+
+        writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
+        writel(period_cycles, imx->mmio_base + MX3_PWMPR);
+
+        cr = MX3_PWMCR_PRESCALER(prescale) |
+                MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
+                MX3_PWMCR_DBGEN | MX3_PWMCR_EN;
+
+        if (cpu_is_mx25())
+                cr |= MX3_PWMCR_CLKSRC_IPG;
+        else
+                cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;
+
+        writel(cr, imx->mmio_base + MX3_PWMCR);
 
         return 0;
 }
 
+static int imx_pwm_config(struct pwm_chip *chip,
+                struct pwm_device *pwm, int duty_ns, int period_ns)
+{
+        struct imx_chip *imx = to_imx_chip(chip);
+
+        return imx->config(chip, pwm, duty_ns, period_ns);
+}
+
 static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
         struct imx_chip *imx = to_imx_chip(chip);
@@ -187,6 +202,11 @@ static int __devinit imx_pwm_probe(struct platform_device *pdev)
         if (imx->mmio_base == NULL)
                 return -EADDRNOTAVAIL;
 
+        if (cpu_is_mx1() || cpu_is_mx21())
+                imx->config = imx_pwm_config_v1;
+        else
+                imx->config = imx_pwm_config_v2;
+
         ret = pwmchip_add(&imx->chip);
         if (ret < 0)
                 return ret;