From b8d74644f34a82a6dcd5f45d5bd57e64f1db0d4d Mon Sep 17 00:00:00 2001 From: Clément Péron Date: Sun, 24 Nov 2019 18:29:04 +0100 Subject: pwm: sun4i: Prefer "mod" clock to unnamed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit New device tree bindings called the source clock of the module "mod" when several clocks are defined. Try to get a clock called "mod" if nothing is found try to get an unnamed clock. Reviewed-by: Uwe Kleine-König Signed-off-by: Clément Péron Signed-off-by: Thierry Reding --- drivers/pwm/pwm-sun4i.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) (limited to 'drivers/pwm/pwm-sun4i.c') diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c index 487899d4cc3f..80026167044b 100644 --- a/drivers/pwm/pwm-sun4i.c +++ b/drivers/pwm/pwm-sun4i.c @@ -362,9 +362,34 @@ static int sun4i_pwm_probe(struct platform_device *pdev) if (IS_ERR(pwm->base)) return PTR_ERR(pwm->base); - pwm->clk = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(pwm->clk)) + /* + * All hardware variants need a source clock that is divided and + * then feeds the counter that defines the output wave form. In the + * device tree this clock is either unnamed or called "mod". + * Some variants (e.g. H6) need another clock to access the + * hardware registers; this is called "bus". + * So we request "mod" first (and ignore the corner case that a + * parent provides a "mod" clock while the right one would be the + * unnamed one of the PWM device) and if this is not found we fall + * back to the first clock of the PWM. + */ + pwm->clk = devm_clk_get_optional(&pdev->dev, "mod"); + if (IS_ERR(pwm->clk)) { + if (PTR_ERR(pwm->rst) != -EPROBE_DEFER) + dev_err(&pdev->dev, "get mod clock failed %pe\n", + pwm->clk); return PTR_ERR(pwm->clk); + } + + if (!pwm->clk) { + pwm->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(pwm->clk)) { + if (PTR_ERR(pwm->rst) != -EPROBE_DEFER) + dev_err(&pdev->dev, "get unnamed clock failed %pe\n", + pwm->clk); + return PTR_ERR(pwm->clk); + } + } pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); if (IS_ERR(pwm->rst)) { -- cgit v1.2.3