From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail-pf1-x42c.google.com ([2607:f8b0:4864:20::42c]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qKrAn-009qst-1k for linux-arm-kernel@lists.infradead.org; Sun, 16 Jul 2023 02:07:47 +0000 Received: by mail-pf1-x42c.google.com with SMTP id d2e1a72fcca58-67ef5af0ce8so3365783b3a.2 for ; Sat, 15 Jul 2023 19:07:44 -0700 (PDT) From: Guiting Shen Subject: [PATCH v6] pwm: atmel: Enable clk when pwm already enabled in bootloader Date: Sun, 16 Jul 2023 10:06:52 +0800 Message-Id: <20230716020652.18557-1-aarongt.shen@gmail.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+lwn-linux-arm-kernel=archive.lwn.net@lists.infradead.org List-Archive: To: claudiu.beznea@microchip.com Cc: linux-pwm@vger.kernel.org, alexandre.belloni@bootlin.com, Guiting Shen , linux-kernel@vger.kernel.org, thierry.reding@gmail.com, u.kleine-koenig@pengutronix.de, linux-arm-kernel@lists.infradead.org The driver would never call clk_enable() if the PWM channel was already enabled in bootloader which lead to dump the warning message "the PWM clock already disabled" when turning off the PWM channel. Add atmel_pwm_enable_clk_if_on() in probe function to enable clock if the PWM channel was already enabled in bootloader. Signed-off-by: Guiting Shen --- drivers/pwm/pwm-atmel.c | 47 +++++++++++++++++++++++++++++++++++++++-- 1 file changed, 45 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index cdbc23649032..fc89282db645 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c @@ -36,7 +36,7 @@ #define PWM_SR 0x0C #define PWM_ISR 0x1C /* Bit field in SR */ -#define PWM_SR_ALL_CH_ON 0x0F +#define PWM_SR_ALL_CH_MASK 0x0F /* The following register is PWM channel related registers */ #define PWM_CH_REG_OFFSET 0x200 @@ -464,6 +464,42 @@ static const struct of_device_id atmel_pwm_dt_ids[] = { }; MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids); +static int atmel_pwm_enable_clk_if_on(struct atmel_pwm_chip *atmel_pwm, bool on) +{ + unsigned int i, cnt = 0; + int ret = 0; + u32 sr; + + sr = atmel_pwm_readl(atmel_pwm, PWM_SR) & PWM_SR_ALL_CH_MASK; + if (!sr) + return 0; + + cnt = bitmap_weight((unsigned long *)&sr, atmel_pwm->chip.npwm); + + if (!on) + goto disable_clk; + + for (i = 0; i < cnt; i++) { + ret = clk_enable(atmel_pwm->clk); + if (ret) { + dev_err(atmel_pwm->chip.dev, + "failed to enable clock for pwm %pe\n", + ERR_PTR(ret)); + + cnt = i; + goto disable_clk; + } + } + + return 0; + +disable_clk: + while (cnt--) + clk_disable(atmel_pwm->clk); + + return ret; +} + static int atmel_pwm_probe(struct platform_device *pdev) { struct atmel_pwm_chip *atmel_pwm; @@ -496,16 +532,23 @@ static int atmel_pwm_probe(struct platform_device *pdev) atmel_pwm->chip.ops = &atmel_pwm_ops; atmel_pwm->chip.npwm = 4; + ret = atmel_pwm_enable_clk_if_on(atmel_pwm, true); + if (ret < 0) + goto unprepare_clk; + ret = pwmchip_add(&atmel_pwm->chip); if (ret < 0) { dev_err(&pdev->dev, "failed to add PWM chip %d\n", ret); - goto unprepare_clk; + goto disable_clk; } platform_set_drvdata(pdev, atmel_pwm); return ret; +disable_clk: + atmel_pwm_enable_clk_if_on(atmel_pwm, false); + unprepare_clk: clk_unprepare(atmel_pwm->clk); return ret; -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel