On 9/11/24 11:28 PM, Frank Li wrote:
On Wed, Sep 11, 2024 at 10:31:40PM +0200, Marek Vasut wrote:
On 9/10/24 9:07 PM, Frank Li wrote:
From: Liu Ying <victor.liu@xxxxxxx>
PWM in i.MX8QXP MIPI subsystem needs the clock '32k'. Use it if the DTS
provides that.
Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
Change from v2 to v3
- use buck clk API
Change from v1 to v2
- remove if check for clk
- use dev_err_probe
- remove int val
---
drivers/pwm/pwm-imx27.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c
index ce9208540f1b8..2a9fba6f9d0a8 100644
--- a/drivers/pwm/pwm-imx27.c
+++ b/drivers/pwm/pwm-imx27.c
@@ -81,10 +81,11 @@
#define MX3_PWMPR_MAX 0xfffe
static const char * const pwm_imx27_clks[] = {"ipg", "per"};
+static const char * const pwm_imx27_opt_clks[] = {"32k"};
#define PWM_IMX27_PER 1
struct pwm_imx27_chip {
- struct clk_bulk_data clks[ARRAY_SIZE(pwm_imx27_clks)];
+ struct clk_bulk_data clks[ARRAY_SIZE(pwm_imx27_clks) + ARRAY_SIZE(pwm_imx27_opt_clks)];
int clks_cnt;
void __iomem *mmio_base;
@@ -371,6 +372,16 @@ static int pwm_imx27_probe(struct platform_device *pdev)
return dev_err_probe(&pdev->dev, ret,
"getting clocks failed\n");
+ for (i = 0; i < ARRAY_SIZE(pwm_imx27_opt_clks); i++)
+ imx->clks[i + imx->clks_cnt].id = pwm_imx27_opt_clks[i];
+
+ ret = devm_clk_bulk_get_optional(&pdev->dev, ARRAY_SIZE(pwm_imx27_opt_clks),
+ imx->clks + imx->clks_cnt);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret, "get optional clocks failed\n");
+
+ imx->clks_cnt += ARRAY_SIZE(pwm_imx27_opt_clks);
+
This will succeed even if the regular PWM clock are invalid or not present,
wouldn't it? I don't think removing that protection is an improvement.
I have not touch regular PWM clock's code. Just add more optional clocks.
devm_clk_bulk_get(imx->clks);
devm_clk_bulk_get_optional(imx->clks + required_cnt);
so imx->clks have two part {required_part, optional_part};
require part is the same as the before. If it invalidate or not present,
driver will fail probe.
Ah, understood, thank you for clarifying.
Also, it is not clear whether the 32kHz clock are really supplying the PWM,
see my comment on 1/3 in this series.
Yes, it is for pwm.
Do the older SoCs (iMX8M or iMX6 or such) also need 32kHz clock for PWM?
I think what I am asking is, what exactly does consume the 32kHz clock
in the PWM IP ?
