linux-kernel - [PATCH v7 13/24] pwm: jz4740: Allow selection of PWM channels 0 and 1

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Message-Id: <20180821171635.22740-14-paul@crapouillou.net>
Date:   Tue, 21 Aug 2018 19:16:24 +0200
From:   Paul Cercueil <paul@...pouillou.net>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Thierry Reding <thierry.reding@...il.com>,
        Mark Rutland <mark.rutland@....com>,
        Ralf Baechle <ralf@...ux-mips.org>,
        Paul Burton <paul.burton@...s.com>,
        Jonathan Corbet <corbet@....net>
Cc:     od@...c.me, Mathieu Malaterre <malat@...ian.org>,
        linux-pwm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-watchdog@...r.kernel.org,
        linux-mips@...ux-mips.org, linux-doc@...r.kernel.org,
        linux-clk@...r.kernel.org, Paul Cercueil <paul@...pouillou.net>
Subject: [PATCH v7 13/24] pwm: jz4740: Allow selection of PWM channels 0 and 1

The TCU channels 0 and 1 were previously reserved for system tasks, and
thus unavailable for PWM.

This commit uses the newly introduced API functions of the ingenic-timer
driver to request/release the TCU channels that should be used as PWM.
This allows all the TCU channels to be used as PWM.

Signed-off-by: Paul Cercueil <paul@...pouillou.net>
---

Notes:
     v6: New patch
    
     v7: No change

 drivers/pwm/pwm-jz4740.c | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
index 1bda8d8e9865..d08274ec007f 100644
--- a/drivers/pwm/pwm-jz4740.c
+++ b/drivers/pwm/pwm-jz4740.c
@@ -43,27 +43,30 @@ static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 	char clk_name[16];
 	int ret;
 
-	/*
-	 * Timers 0 and 1 are used for system tasks, so they are unavailable
-	 * for use as PWMs.
-	 */
-	if (pwm->hwpwm < 2)
-		return -EBUSY;
+	ret = ingenic_tcu_request_channel(pwm->hwpwm);
+	if (ret)
+		return ret;
 
 	snprintf(clk_name, sizeof(clk_name), "timer%u", pwm->hwpwm);
 
 	clk = clk_get(chip->dev, clk_name);
-	if (IS_ERR(clk))
-		return PTR_ERR(clk);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto err_free_channel;
+	}
 
 	ret = clk_prepare_enable(clk);
-	if (ret) {
-		clk_put(clk);
-		return ret;
-	}
+	if (ret)
+		goto err_clk_put;
 
 	jz->clks[pwm->hwpwm] = clk;
 	return 0;
+
+err_clk_put:
+	clk_put(clk);
+err_free_channel:
+	ingenic_tcu_release_channel(pwm->hwpwm);
+	return ret;
 }
 
 static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
@@ -73,6 +76,7 @@ static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 
 	clk_disable_unprepare(clk);
 	clk_put(clk);
+	ingenic_tcu_release_channel(pwm->hwpwm);
 }
 
 static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
-- 
2.11.0