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From: Paul Cercueil <paul@crapouillou.net>
To: Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Thierry Reding <thierry.reding@gmail.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Wim Van Sebroeck <wim@linux-watchdog.org>,
	Guenter Roeck <linux@roeck-us.net>,
	Ralf Baechle <ralf@linux-mips.org>,
	Paul Burton <paul.burton@mips.com>,
	James Hogan <jhogan@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
	Lee Jones <lee.jones@linaro.org>,
	Mathieu Malaterre <malat@debian.org>,
	Ezequiel Garcia <ezequiel@collabora.co.uk>
Cc: linux-pwm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org,
	linux-mips@linux-mips.org, linux-doc@vger.kernel.org,
	linux-clk@vger.kernel.org, Paul Cercueil <paul@crapouillou.net>
Subject: [PATCH v6 12/24] pwm: jz4740: Use regmap and clocks from TCU driver
Date: Thu,  9 Aug 2018 23:44:02 +0200
Message-ID: <20180809214414.20905-13-paul@crapouillou.net> (raw)
In-Reply-To: <20180809214414.20905-1-paul@crapouillou.net>

The ingenic-timer "TCU" driver provides us with a regmap, that we can
use to safely access the TCU registers.

It also provides us with clocks, that can be (un)gated, reparented or
reclocked from devicetree, instead of having these settings hardcoded in
this driver.

While this driver is devicetree-compatible, it is never (as of now)
probed from devicetree, so this change does not introduce a ABI problem
with current devicetree files.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 drivers/pwm/Kconfig      |   2 +
 drivers/pwm/pwm-jz4740.c | 124 +++++++++++++++++++++++++++++++----------------
 2 files changed, 83 insertions(+), 43 deletions(-)

 v5: New patch

 v6: Drop requirement of probing from devicetree

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index a4d262db9945..58359bf22b96 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -202,6 +202,8 @@ config PWM_IMX
 config PWM_JZ4740
 	tristate "Ingenic JZ47xx PWM support"
 	depends on MACH_INGENIC
+	depends on COMMON_CLK
+	select INGENIC_TIMER
 	help
 	  Generic PWM framework driver for Ingenic JZ47xx based
 	  machines.
diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
index a7b134af5e04..1bda8d8e9865 100644
--- a/drivers/pwm/pwm-jz4740.c
+++ b/drivers/pwm/pwm-jz4740.c
@@ -14,21 +14,21 @@
  */
 
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
 #include <linux/kernel.h>
+#include <linux/mfd/ingenic-tcu.h>
 #include <linux/module.h>
-#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/pwm.h>
-
-#include <asm/mach-jz4740/timer.h>
+#include <linux/regmap.h>
 
 #define NUM_PWM 8
 
 struct jz4740_pwm_chip {
 	struct pwm_chip chip;
-	struct clk *clk;
+	struct clk *clks[NUM_PWM];
+	struct regmap *map;
 };
 
 static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
@@ -38,6 +38,11 @@ static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
 
 static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
+	struct jz4740_pwm_chip *jz = to_jz4740(chip);
+	struct clk *clk;
+	char clk_name[16];
+	int ret;
+
 	/*
 	 * Timers 0 and 1 are used for system tasks, so they are unavailable
 	 * for use as PWMs.
@@ -45,65 +50,89 @@ static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 	if (pwm->hwpwm < 2)
 		return -EBUSY;
 
-	jz4740_timer_start(pwm->hwpwm);
+	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);
 
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		clk_put(clk);
+		return ret;
+	}
+
+	jz->clks[pwm->hwpwm] = clk;
 	return 0;
 }
 
 static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	jz4740_timer_set_ctrl(pwm->hwpwm, 0);
+	struct jz4740_pwm_chip *jz = to_jz4740(chip);
+	struct clk *clk = jz->clks[pwm->hwpwm];
 
-	jz4740_timer_stop(pwm->hwpwm);
+	clk_disable_unprepare(clk);
+	clk_put(clk);
 }
 
 static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
+	struct jz4740_pwm_chip *jz = to_jz4740(chip);
 
-	ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
-	jz4740_timer_enable(pwm->hwpwm);
+	/* Enable PWM output */
+	regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+				TCU_TCSR_PWM_EN, TCU_TCSR_PWM_EN);
 
+	/* Start counter */
+	regmap_write(jz->map, TCU_REG_TESR, BIT(pwm->hwpwm));
 	return 0;
 }
 
 static void jz4740_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->hwpwm);
+	struct jz4740_pwm_chip *jz = to_jz4740(chip);
 
 	/* Disable PWM output.
 	 * In TCU2 mode (channel 1/2 on JZ4750+), this must be done before the
 	 * counter is stopped, while in TCU1 mode the order does not matter.
 	 */
-	ctrl &= ~JZ_TIMER_CTRL_PWM_ENABLE;
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
+	regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+				TCU_TCSR_PWM_EN, 0);
 
 	/* Stop counter */
-	jz4740_timer_disable(pwm->hwpwm);
+	regmap_write(jz->map, TCU_REG_TECR, BIT(pwm->hwpwm));
 }
 
 static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 			     int duty_ns, int period_ns)
 {
 	struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
+	struct clk *clk = jz4740->clks[pwm->hwpwm];
+	unsigned long rate, new_rate, period, duty;
 	unsigned long long tmp;
-	unsigned long period, duty;
-	unsigned int prescaler = 0;
-	uint16_t ctrl;
+	unsigned int tcsr;
 	bool is_enabled;
 
-	tmp = (unsigned long long)clk_get_rate(jz4740->clk) * period_ns;
-	do_div(tmp, 1000000000);
-	period = tmp;
+	rate = clk_get_rate(clk);
+
+	for (;;) {
+		tmp = (unsigned long long) rate * period_ns;
+		do_div(tmp, 1000000000);
 
-	while (period > 0xffff && prescaler < 6) {
-		period >>= 2;
-		++prescaler;
+		if (tmp <= 0xffff)
+			break;
+
+		new_rate = clk_round_rate(clk, rate / 2);
+
+		if (new_rate < rate)
+			rate = new_rate;
+		else
+			return -EINVAL;
 	}
 
-	if (prescaler == 6)
-		return -EINVAL;
+	clk_set_rate(clk, rate);
+
+	period = tmp;
 
 	tmp = (unsigned long long)period * duty_ns;
 	do_div(tmp, period_ns);
@@ -112,18 +141,23 @@ static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (duty >= period)
 		duty = period - 1;
 
-	is_enabled = jz4740_timer_is_enabled(pwm->hwpwm);
+	regmap_read(jz4740->map, TCU_REG_TER, &tcsr);
+	is_enabled = tcsr & BIT(pwm->hwpwm);
 	if (is_enabled)
 		jz4740_pwm_disable(chip, pwm);
 
-	jz4740_timer_set_count(pwm->hwpwm, 0);
-	jz4740_timer_set_duty(pwm->hwpwm, duty);
-	jz4740_timer_set_period(pwm->hwpwm, period);
+	/* Set abrupt shutdown */
+	regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
+				TCU_TCSR_PWM_SD, TCU_TCSR_PWM_SD);
+
+	/* Reset counter to 0 */
+	regmap_write(jz4740->map, TCU_REG_TCNTc(pwm->hwpwm), 0);
 
-	ctrl = JZ_TIMER_CTRL_PRESCALER(prescaler) | JZ_TIMER_CTRL_SRC_EXT |
-		JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;
+	/* Set duty */
+	regmap_write(jz4740->map, TCU_REG_TDHRc(pwm->hwpwm), duty);
 
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
+	/* Set period */
+	regmap_write(jz4740->map, TCU_REG_TDFRc(pwm->hwpwm), period);
 
 	if (is_enabled)
 		jz4740_pwm_enable(chip, pwm);
@@ -134,18 +168,19 @@ static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 static int jz4740_pwm_set_polarity(struct pwm_chip *chip,
 		struct pwm_device *pwm, enum pwm_polarity polarity)
 {
-	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
+	struct jz4740_pwm_chip *jz = to_jz4740(chip);
 
 	switch (polarity) {
 	case PWM_POLARITY_NORMAL:
-		ctrl &= ~JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
+		regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+				TCU_TCSR_PWM_INITL_HIGH, 0);
 		break;
 	case PWM_POLARITY_INVERSED:
-		ctrl |= JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
+		regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+			TCU_TCSR_PWM_INITL_HIGH, TCU_TCSR_PWM_INITL_HIGH);
 		break;
 	}
 
-	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
 	return 0;
 }
 
@@ -162,16 +197,19 @@ static const struct pwm_ops jz4740_pwm_ops = {
 static int jz4740_pwm_probe(struct platform_device *pdev)
 {
 	struct jz4740_pwm_chip *jz4740;
+	struct device *dev = &pdev->dev;
 
-	jz4740 = devm_kzalloc(&pdev->dev, sizeof(*jz4740), GFP_KERNEL);
+	jz4740 = devm_kzalloc(dev, sizeof(*jz4740), GFP_KERNEL);
 	if (!jz4740)
 		return -ENOMEM;
 
-	jz4740->clk = devm_clk_get(&pdev->dev, "ext");
-	if (IS_ERR(jz4740->clk))
-		return PTR_ERR(jz4740->clk);
+	jz4740->map = dev_get_regmap(dev->parent, NULL);
+	if (!jz4740->map) {
+		dev_err(dev, "regmap not found\n");
+		return -EINVAL;
+	}
 
-	jz4740->chip.dev = &pdev->dev;
+	jz4740->chip.dev = dev;
 	jz4740->chip.ops = &jz4740_pwm_ops;
 	jz4740->chip.npwm = NUM_PWM;
 	jz4740->chip.base = -1;
-- 
2.11.0


  parent reply index

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-09 21:43 [PATCH v6 00/24] Ingenic TCU patchset v6 Paul Cercueil
2018-08-09 21:43 ` [PATCH v6 01/24] mfd: Add ingenic-tcu.h header Paul Cercueil
2018-08-09 21:43 ` [PATCH v6 02/24] dt-bindings: ingenic: Add DT bindings for TCU clocks Paul Cercueil
2018-08-09 21:43 ` [PATCH v6 03/24] doc: Add doc for the Ingenic TCU hardware Paul Cercueil
2018-08-09 21:43 ` [PATCH v6 04/24] dt-bindings: Add doc for the Ingenic TCU drivers Paul Cercueil
2018-08-13 15:24   ` Rob Herring
2018-08-09 21:43 ` [PATCH v6 05/24] clocksource: Add a new timer-ingenic driver Paul Cercueil
2018-08-09 21:43 ` [PATCH v6 06/24] clocksource: Add driver for the Ingenic JZ47xx OST Paul Cercueil
2018-08-14  9:42   ` Mathieu Malaterre
2018-08-16 16:07     ` Paul Cercueil
2018-08-09 21:43 ` [PATCH v6 07/24] MAINTAINERS: Add myself as maintainer for Ingenic TCU drivers Paul Cercueil
2018-08-09 21:43 ` [PATCH v6 08/24] watchdog: jz4740: Use WDT clock provided by TCU driver Paul Cercueil
2018-08-10 13:36   ` Guenter Roeck
2018-08-09 21:43 ` [PATCH v6 09/24] watchdog: jz4740: Use regmap " Paul Cercueil
2018-08-10 13:37   ` Guenter Roeck
2018-08-09 21:44 ` [PATCH v6 10/24] watchdog: jz4740: Avoid starting watchdog in set_timeout Paul Cercueil
2018-08-10 13:37   ` Guenter Roeck
2018-08-09 21:44 ` [PATCH v6 11/24] watchdog: jz4740: Drop dependency on MACH_JZ47xx, use COMPILE_TEST Paul Cercueil
2018-08-10 13:38   ` Guenter Roeck
2018-08-09 21:44 ` Paul Cercueil [this message]
2018-08-09 21:44 ` [PATCH v6 13/24] pwm: jz4740: Allow selection of PWM channels 0 and 1 Paul Cercueil
2018-08-09 21:44 ` [PATCH v6 14/24] pwm: jz4740: Drop dependency on MACH_INGENIC, use COMPILE_TEST Paul Cercueil
2018-08-09 21:44 ` [PATCH v6 15/24] pwm: jz4740: Remove unused devicetree compatible strings Paul Cercueil
2018-08-09 21:44 ` [PATCH v6 16/24] pwm: jz4740: Add support for the JZ4725B Paul Cercueil
2018-08-09 21:44 ` [PATCH v6 17/24] clk: jz4740: Add TCU clock Paul Cercueil
2018-08-09 21:44 ` [PATCH v6 18/24] MIPS: Kconfig: Select TCU timer driver when MACH_INGENIC is set Paul Cercueil
2018-08-09 21:44 ` [PATCH v6 19/24] MIPS: jz4740: Add DTS nodes for the TCU drivers Paul Cercueil
2018-08-09 21:44 ` [PATCH v6 20/24] MIPS: qi_lb60: Move PWM devices to devicetree Paul Cercueil
2018-08-09 21:46 ` [PATCH v6 21/24] MIPS: qi_lb60: Reduce system timer and clocksource to 750 kHz Paul Cercueil
2018-08-09 21:46 ` [PATCH v6 22/24] MIPS: CI20: Reduce system timer and clocksource to 3 MHz Paul Cercueil
2018-08-09 21:47 ` [PATCH v6 23/24] MIPS: CI20: defconfig: enable OST driver Paul Cercueil
2018-08-09 21:48 ` [PATCH v6 24/24] MIPS: jz4740: Drop obsolete code Paul Cercueil

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