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);
/*
* 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 = udiv32(max * duty_ns, period_ns);
writel(max - p, imx->mmio_base + MX1_PWMS);
return 0;
}
static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct imx_chip *imx = to_imx_chip(chip);
imx->set_enable(chip, false);
/* clk_disable_unprepare(imx->clk_per); */
}
static int imx_pwm_enable(struct pwm_chip *chip)
{
struct imx_chip *imx = to_imx_chip(chip);
imx->set_enable(chip, true);
return 0;
}
static int imx_pwm_config(struct pwm_chip *chip,
int duty_ns, int period_ns)
{
struct imx_chip *imx = to_imx_chip(chip);
int ret;
ret = imx->config(chip, duty_ns, period_ns);
return ret;
}
static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct imx_chip *imx = to_imx_chip(chip);
int ret;
ret = clk_prepare_enable(imx->clk_per);
if (ret)
return ret;
imx->set_enable(chip, true);
return 0;
}
static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
{
struct imx_chip *imx = to_imx_chip(chip);
u32 val;
val = readl(imx->mmio_base + MX3_PWMCR);
if (enable)
val |= MX3_PWMCR_EN;
else
val &= ~MX3_PWMCR_EN;
writel(val, imx->mmio_base + MX3_PWMCR);
}
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);
int ret;
ret = clk_prepare_enable(imx->clk_ipg);
if (ret)
return ret;
ret = imx->config(chip, pwm, duty_ns, period_ns);
/* clk_disable_unprepare(imx->clk_ipg); */
return ret;
}
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_per);
c = c * period_ns;
c = udiv64(c, 1000000000);
period_cycles = c;
prescale = period_cycles / 0x10000 + 1;
period_cycles = udiv32(period_cycles, prescale);
c = (unsigned long long)period_cycles * duty_ns;
c = udiv64(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_CLKSRC_IPG_HIGH;
if (test_bit(PWMF_ENABLED, &pwm->flags))
cr |= MX3_PWMCR_EN;
writel(cr, imx->mmio_base + MX3_PWMCR);
return 0;
}
static void imx_pwm_disable(struct pwm_chip *chip)
{
struct imx_chip *imx = to_imx_chip(chip);
imx->set_enable(chip, false);
}