@@ -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;