[PATCH v3 06/11] pwm: imx: Move PWMv2 wait for fifo slot code to a separate function

Lukasz Majewski
2016-11-01T07:37:17Z

The code, which waits for fifo slot, has been extracted from
imx_pwm_config_v2 function and moved to new one - imx_pwm_wait_fifo_slot().

This change reduces the overall size of imx_pwm_config_v2() and prepares
it for atomic PWM operation.

Suggested-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
---
Changes for v3:
- None

Changes for v2:
- None
---
drivers/pwm/pwm-imx.c | 43 +++++++++++++++++++++++++------------------
1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
index b4e5803..ebe9b0c 100644
--- a/drivers/pwm/pwm-imx.c
+++ b/drivers/pwm/pwm-imx.c
@@ -137,18 +137,36 @@ static void imx_pwm_sw_reset(struct pwm_chip *chip)
dev_warn(dev, "software reset timeout\n");
}

+static void imx_pwm_wait_fifo_slot(struct pwm_chip *chip,
+ struct pwm_device *pwm)
+{
+ struct imx_chip *imx = to_imx_chip(chip);
+ struct device *dev = chip->dev;
+ unsigned int period_ms;
+ int fifoav;
+ u32 sr;
+
+ sr = readl(imx->mmio_base + MX3_PWMSR);
+ fifoav = sr & MX3_PWMSR_FIFOAV_MASK;
+ if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) {
+ period_ms = DIV_ROUND_UP(pwm_get_period(pwm),
+ NSEC_PER_MSEC);
+ msleep(period_ms);
+
+ sr = readl(imx->mmio_base + MX3_PWMSR);
+ if (fifoav == (sr & MX3_PWMSR_FIFOAV_MASK))
+ dev_warn(dev, "there is no free FIFO slot\n");
+ }
+}

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);
- struct device *dev = chip->dev;
unsigned long long c;
unsigned long period_cycles, duty_cycles, prescale;
- unsigned int period_ms;
bool enable = pwm_is_enabled(pwm);
- int fifoav;
- u32 cr, sr;
+ u32 cr;

/*
* i.MX PWMv2 has a 4-word sample FIFO.
@@ -157,21 +175,10 @@ static int imx_pwm_config_v2(struct pwm_chip *chip,
* wait for a full PWM cycle to get a relinquished FIFO slot
* when the controller is enabled and the FIFO is fully loaded.
*/
- if (enable) {
- sr = readl(imx->mmio_base + MX3_PWMSR);
- fifoav = sr & MX3_PWMSR_FIFOAV_MASK;
- if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) {
- period_ms = DIV_ROUND_UP(pwm_get_period(pwm),
- NSEC_PER_MSEC);
- msleep(period_ms);
-
- sr = readl(imx->mmio_base + MX3_PWMSR);
- if (fifoav == (sr & MX3_PWMSR_FIFOAV_MASK))
- dev_warn(dev, "there is no free FIFO slot\n");
- }
- } else {
+ if (enable)
+ imx_pwm_wait_fifo_slot(chip, pwm);
+ else
imx_pwm_sw_reset(chip);
- }

c = clk_get_rate(imx->clk_per);
c = c * period_ns;
--
2.1.4