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pwm: rockchip: use the completion to check whether frequency result is valid

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In some cases, the frequency result may not be valid after sleeping
for specified time due to the interrupt preemption. Therefore, it may
be better to use the completion and set the actual wait time to the
3/2 of the specified delay time.

Change-Id: I5b9879ff9eaaf41ace5534040e0e47ec9bca7cc0
Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
This commit is contained in:
Damon Ding
2025-04-16 14:12:29 +08:00
committed by Tao Huang
parent a9be2283b5
commit 4fcd88017a
1 changed files with 18 additions and 15 deletions
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33
drivers/pwm/pwm-rockchip.c
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@@ -314,6 +314,7 @@ struct rockchip_pwm_chip {
struct resource *res;
struct dentry *debugfs;
struct completion ir_trans_completion;
struct completion freq_meter_completion;
void __iomem *base;
unsigned long clk_rate;
unsigned long is_clk_enabled;
@@ -329,7 +330,6 @@ struct rockchip_pwm_chip {
bool wave_support;
bool biphasic_support;
bool ledc_support;
bool freq_res_valid;
bool biphasic_res_valid;
int channel_id;
int irq;
@@ -740,7 +740,7 @@ static irqreturn_t rockchip_pwm_irq_v4(int irq, void *data)
if (val & FREQ_INT) {
writel_relaxed(FREQ_INT, pc->base + INTSTS);
pc->freq_res_valid = true;
complete(&pc->freq_meter_completion);
ret = IRQ_HANDLED;
}
@@ -1241,7 +1241,7 @@ static int rockchip_pwm_set_freq_meter_v4(struct pwm_chip *chip, struct pwm_devi
int ret;
if (enable) {
pc->freq_res_valid = false;
reinit_completion(&pc->freq_meter_completion);
arbiter = BIT(pc->channel_id) << FREQ_READ_LOCK_SHIFT |
BIT(pc->channel_id) << FREQ_GRANT_SHIFT;
@@ -1281,22 +1281,22 @@ static int rockchip_pwm_get_freq_meter_result_v4(struct pwm_chip *chip, struct p
struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
u32 freq_res;
u32 freq_timer;
int ret = 0;
usleep_range(delay_ms * USEC_PER_MSEC, delay_ms * USEC_PER_MSEC);
if (pc->freq_res_valid) {
freq_res = readl_relaxed(pc->base + FREQ_RESULT_VALUE);
freq_timer = readl_relaxed(pc->base + FREQ_TIMER_VALUE);
*freq_hz = DIV_ROUND_CLOSEST_ULL((u64)pc->clk_rate * freq_res, freq_timer);
if (!*freq_hz)
return -EINVAL;
pc->freq_res_valid = false;
} else {
dev_err(chip->dev, "failed to wait for freq_meter interrupt\n");
ret = wait_for_completion_timeout(&pc->freq_meter_completion,
msecs_to_jiffies(delay_ms * 3 / 2));
if (!ret) {
dev_err(chip->dev, "Failed to wait for PWM%d frequency meter result to be valid\n",
pc->channel_id);
return -ETIMEDOUT;
}
freq_res = readl_relaxed(pc->base + FREQ_RESULT_VALUE);
freq_timer = readl_relaxed(pc->base + FREQ_TIMER_VALUE);
*freq_hz = DIV_ROUND_CLOSEST_ULL((u64)pc->clk_rate * freq_res, freq_timer);
if (!*freq_hz)
return -EINVAL;
return 0;
}
@@ -2373,6 +2373,9 @@ static int rockchip_pwm_probe(struct platform_device *pdev)
goto err_pclk;
}
if (pc->freq_meter_support)
init_completion(&pc->freq_meter_completion);
if (pc->data->funcs.irq_handler) {
/*
* For pwm v1-v3, the older platform may not support interrupt, and