Linux-Watchdog Archive on lore.kernel.org
 help / color / Atom feed
From: Michael Walle <michael@walle.cc>
To: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org,
	linux-pwm@vger.kernel.org, linux-watchdog@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: "Linus Walleij" <linus.walleij@linaro.org>,
	"Bartosz Golaszewski" <bgolaszewski@baylibre.com>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Jean Delvare" <jdelvare@suse.com>,
	"Guenter Roeck" <linux@roeck-us.net>,
	"Lee Jones" <lee.jones@linaro.org>,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Wim Van Sebroeck" <wim@linux-watchdog.org>,
	"Shawn Guo" <shawnguo@kernel.org>, "Li Yang" <leoyang.li@nxp.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Jason Cooper" <jason@lakedaemon.net>,
	"Marc Zyngier" <maz@kernel.org>,
	"Mark Brown" <broonie@kernel.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
	"Michael Walle" <michael@walle.cc>
Subject: [PATCH v4 05/11] pwm: add support for sl28cpld PWM controller
Date: Thu,  4 Jun 2020 23:10:33 +0200
Message-ID: <20200604211039.12689-6-michael@walle.cc> (raw)
In-Reply-To: <20200604211039.12689-1-michael@walle.cc>

Add support for the PWM controller of the sl28cpld board management
controller. This is part of a multi-function device driver.

The controller has one PWM channel and can just generate four distinct
frequencies.

Signed-off-by: Michael Walle <michael@walle.cc>
---
 drivers/pwm/Kconfig        |  10 ++
 drivers/pwm/Makefile       |   1 +
 drivers/pwm/pwm-sl28cpld.c | 201 +++++++++++++++++++++++++++++++++++++
 3 files changed, 212 insertions(+)
 create mode 100644 drivers/pwm/pwm-sl28cpld.c

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index cb8d739067d2..a39371c11ff6 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -437,6 +437,16 @@ config PWM_SIFIVE
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-sifive.
 
+config PWM_SL28CPLD
+	tristate "Kontron sl28 PWM support"
+	depends on MFD_SL28CPLD
+	help
+	  Generic PWM framework driver for board management controller
+	  found on the Kontron sl28 CPLD.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm-sl28cpld.
+
 config PWM_SPEAR
 	tristate "STMicroelectronics SPEAr PWM support"
 	depends on PLAT_SPEAR || COMPILE_TEST
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index a59c710e98c7..c479623724e8 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_PWM_RENESAS_TPU)	+= pwm-renesas-tpu.o
 obj-$(CONFIG_PWM_ROCKCHIP)	+= pwm-rockchip.o
 obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_SIFIVE)	+= pwm-sifive.o
+obj-$(CONFIG_PWM_SL28CPLD)	+= pwm-sl28cpld.o
 obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
 obj-$(CONFIG_PWM_SPRD)		+= pwm-sprd.o
 obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
diff --git a/drivers/pwm/pwm-sl28cpld.c b/drivers/pwm/pwm-sl28cpld.c
new file mode 100644
index 000000000000..d82303f509f5
--- /dev/null
+++ b/drivers/pwm/pwm-sl28cpld.c
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * sl28cpld PWM driver.
+ *
+ * Copyright 2019 Kontron Europe GmbH
+ */
+
+#include <linux/bitfield.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+
+/*
+ * PWM timer block registers.
+ */
+#define PWM_CTRL		0x00
+#define   PWM_ENABLE		BIT(7)
+#define   PWM_MODE_250HZ	0
+#define   PWM_MODE_500HZ	1
+#define   PWM_MODE_1KHZ		2
+#define   PWM_MODE_2KHZ		3
+#define   PWM_MODE_MASK		GENMASK(1, 0)
+#define PWM_CYCLE		0x01
+#define   PWM_CYCLE_MAX		0x7f
+
+struct sl28cpld_pwm {
+	struct pwm_chip pwm_chip;
+	struct regmap *regmap;
+	u32 offset;
+};
+
+struct sl28cpld_pwm_periods {
+	u8 ctrl;
+	unsigned long duty_cycle;
+};
+
+struct sl28cpld_pwm_config {
+	unsigned long period_ns;
+	u8 max_duty_cycle;
+};
+
+static struct sl28cpld_pwm_config sl28cpld_pwm_config[] = {
+	[PWM_MODE_250HZ] = { .period_ns = 4000000, .max_duty_cycle = 0x80 },
+	[PWM_MODE_500HZ] = { .period_ns = 2000000, .max_duty_cycle = 0x40 },
+	[PWM_MODE_1KHZ] = { .period_ns = 1000000, .max_duty_cycle = 0x20 },
+	[PWM_MODE_2KHZ] = { .period_ns =  500000, .max_duty_cycle = 0x10 },
+};
+
+static inline struct sl28cpld_pwm *to_sl28cpld_pwm(struct pwm_chip *chip)
+{
+	return container_of(chip, struct sl28cpld_pwm, pwm_chip);
+}
+
+static void sl28cpld_pwm_get_state(struct pwm_chip *chip,
+				   struct pwm_device *pwm,
+				   struct pwm_state *state)
+{
+	struct sl28cpld_pwm *spc = to_sl28cpld_pwm(chip);
+	static struct sl28cpld_pwm_config *config;
+	unsigned int reg;
+	unsigned long cycle;
+	unsigned int mode;
+
+	regmap_read(spc->regmap, spc->offset + PWM_CTRL, &reg);
+
+	state->enabled = reg & PWM_ENABLE;
+
+	mode = FIELD_GET(PWM_MODE_MASK, reg);
+	config = &sl28cpld_pwm_config[mode];
+	state->period = config->period_ns;
+
+	regmap_read(spc->regmap, spc->offset + PWM_CYCLE, &reg);
+	cycle = reg * config->period_ns;
+	state->duty_cycle = DIV_ROUND_CLOSEST_ULL(cycle,
+						  config->max_duty_cycle);
+}
+
+static int sl28cpld_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			      const struct pwm_state *state)
+{
+	struct sl28cpld_pwm *spc = to_sl28cpld_pwm(chip);
+	struct sl28cpld_pwm_config *config;
+	unsigned long long cycle;
+	int ret;
+	int mode;
+	u8 ctrl;
+
+	/* update config, first search best matching period */
+	for (mode = 0; mode < ARRAY_SIZE(sl28cpld_pwm_config); mode++) {
+		config = &sl28cpld_pwm_config[mode];
+		if (state->period == config->period_ns)
+			break;
+	}
+
+	if (mode == ARRAY_SIZE(sl28cpld_pwm_config))
+		return -EINVAL;
+
+	ctrl = FIELD_PREP(PWM_MODE_MASK, mode);
+	if (state->enabled)
+		ctrl |= PWM_ENABLE;
+
+	cycle = state->duty_cycle * config->max_duty_cycle;
+	do_div(cycle, state->period);
+
+	/*
+	 * The hardware doesn't allow to set max_duty_cycle if the
+	 * 250Hz mode is enabled. But since this is "all-high" output
+	 * just use the 500Hz mode with the duty cycle to max value.
+	 */
+	if (cycle == config->max_duty_cycle) {
+		ctrl &= ~PWM_MODE_MASK;
+		ctrl |= FIELD_PREP(PWM_MODE_MASK, PWM_MODE_500HZ);
+		cycle = PWM_CYCLE_MAX;
+	}
+
+	ret = regmap_write(spc->regmap, spc->offset + PWM_CTRL, ctrl);
+	if (ret)
+		return ret;
+
+	return regmap_write(spc->regmap, spc->offset + PWM_CYCLE, (u8)cycle);
+}
+
+static const struct pwm_ops sl28cpld_pwm_ops = {
+	.apply = sl28cpld_pwm_apply,
+	.get_state = sl28cpld_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
+static int sl28cpld_pwm_probe(struct platform_device *pdev)
+{
+	struct sl28cpld_pwm *pwm;
+	struct pwm_chip *chip;
+	int ret;
+
+	if (!pdev->dev.parent)
+		return -ENODEV;
+
+	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+	if (!pwm)
+		return -ENOMEM;
+
+	pwm->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!pwm->regmap)
+		return -ENODEV;
+
+	ret = device_property_read_u32(&pdev->dev, "reg", &pwm->offset);
+	if (ret)
+		return -EINVAL;
+
+	/* initialize struct pwm_chip */
+	chip = &pwm->pwm_chip;
+	chip->dev = &pdev->dev;
+	chip->ops = &sl28cpld_pwm_ops;
+	chip->base = -1;
+	chip->npwm = 1;
+
+	ret = pwmchip_add(&pwm->pwm_chip);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, pwm);
+
+	return 0;
+}
+
+static int sl28cpld_pwm_remove(struct platform_device *pdev)
+{
+	struct sl28cpld_pwm *pwm = platform_get_drvdata(pdev);
+
+	return pwmchip_remove(&pwm->pwm_chip);
+}
+
+static const struct of_device_id sl28cpld_pwm_of_match[] = {
+	{ .compatible = "kontron,sl28cpld-pwm" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sl28cpld_pwm_of_match);
+
+static const struct platform_device_id sl28cpld_pwm_id_table[] = {
+	{"sl28cpld-pwm"},
+	{},
+};
+MODULE_DEVICE_TABLE(platform, sl28cpld_pwm_id_table);
+
+static struct platform_driver sl28cpld_pwm_driver = {
+	.probe = sl28cpld_pwm_probe,
+	.remove	= sl28cpld_pwm_remove,
+	.id_table = sl28cpld_pwm_id_table,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = sl28cpld_pwm_of_match,
+	},
+};
+module_platform_driver(sl28cpld_pwm_driver);
+
+MODULE_DESCRIPTION("sl28cpld PWM Driver");
+MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
+MODULE_LICENSE("GPL");
-- 
2.20.1


  parent reply index

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-04 21:10 [PATCH v4 00/11] Add support for Kontron sl28cpld Michael Walle
2020-06-04 21:10 ` [PATCH v4 01/11] dt-bindings: mfd: Add bindings for sl28cpld Michael Walle
2020-06-09 16:28   ` Rob Herring
2020-06-04 21:10 ` [PATCH v4 02/11] mfd: Add support for Kontron sl28cpld management controller Michael Walle
2020-06-05  6:57   ` Lee Jones
2020-06-05  9:51     ` Michael Walle
2020-06-05 10:50     ` Mark Brown
2020-06-05 20:07       ` Michael Walle
2020-06-06 11:46         ` Mark Brown
2020-06-06 12:45           ` Michael Walle
2020-06-08  8:28             ` Lee Jones
2020-06-08 10:02               ` Andy Shevchenko
2020-06-08 15:41                 ` Michael Walle
2020-06-08 18:56                   ` Lee Jones
2020-06-08 21:09                     ` Michael Walle
2020-06-09  6:47                       ` Lee Jones
2020-06-09 14:38                         ` Michael Walle
2020-06-09 14:42                           ` Mark Brown
2020-06-09 15:01                             ` Michael Walle
2020-06-09 17:15                               ` Rob Herring
2020-06-09 17:29                                 ` Mark Brown
2020-06-09 18:41                                 ` Lee Jones
2020-06-09 15:19                           ` Lee Jones
2020-06-09 15:30                             ` Michael Walle
2020-06-09 19:45                               ` Lee Jones
2020-06-10  7:10                                 ` Michael Walle
2020-06-10  7:19                                   ` Lee Jones
2020-06-10  7:49                                     ` Michael Walle
2020-06-10  7:56                                       ` Lee Jones
2020-06-10  9:27                                         ` Michael Walle
2020-06-10 18:30                                           ` Lee Jones
2020-06-10 17:16                                     ` Rob Herring
2020-06-10 18:02                                       ` Lee Jones
2020-06-08 18:20                 ` Lee Jones
2020-06-09 16:54               ` Rob Herring
2020-06-09 18:52                 ` Lee Jones
2020-06-05  8:01   ` Andy Shevchenko
2020-06-05  8:02     ` Andy Shevchenko
2020-06-05 10:09     ` Michael Walle
2020-06-05 10:48       ` Andy Shevchenko
2020-06-05 11:51         ` Michael Walle
2020-06-04 21:10 ` [PATCH v4 03/11] irqchip: add sl28cpld interrupt controller support Michael Walle
2020-06-05  1:26   ` kernel test robot
2020-06-05  8:07   ` Andy Shevchenko
2020-06-08 15:12   ` kernel test robot
2020-06-04 21:10 ` [PATCH v4 04/11] watchdog: add support for sl28cpld watchdog Michael Walle
2020-06-05  8:14   ` Andy Shevchenko
2020-06-05 10:24     ` Michael Walle
2020-06-05 10:50       ` Andy Shevchenko
2020-06-05 13:52         ` Guenter Roeck
2020-06-05 14:09           ` Andy Shevchenko
2020-06-05 15:05             ` Guenter Roeck
2020-06-05 16:04               ` Andy Shevchenko
2020-06-05 16:34                 ` Guenter Roeck
2020-06-04 21:10 ` Michael Walle [this message]
2020-06-05  8:15   ` [PATCH v4 05/11] pwm: add support for sl28cpld PWM controller Andy Shevchenko
2020-06-05  8:49   ` Lee Jones
2020-06-05  9:33     ` Andy Shevchenko
2020-06-05 11:39     ` Michael Walle
2020-06-05 18:17     ` Michael Walle
2020-06-08  7:46       ` Lee Jones
2020-06-04 21:10 ` [PATCH v4 06/11] gpio: add support for the sl28cpld GPIO controller Michael Walle
2020-06-05 12:00   ` Andy Shevchenko
2020-06-05 12:42     ` Michael Walle
2020-06-05 13:15       ` Andy Shevchenko
2020-06-05 18:44         ` Michael Walle
2020-06-05 21:19           ` Andy Shevchenko
2020-06-04 21:10 ` [PATCH v4 07/11] hwmon: add support for the sl28cpld hardware monitoring controller Michael Walle
2020-06-05 12:06   ` Andy Shevchenko
2020-06-04 21:10 ` [PATCH v4 08/11] arm64: dts: freescale: sl28: enable sl28cpld Michael Walle
2020-06-04 21:10 ` [PATCH v4 09/11] arm64: dts: freescale: sl28: map GPIOs to input events Michael Walle
2020-06-04 21:10 ` [PATCH v4 10/11] arm64: dts: freescale: sl28: enable LED support Michael Walle
2020-06-04 21:10 ` [PATCH v4 11/11] arm64: dts: freescale: sl28: enable fan support Michael Walle
2020-06-05  6:13 ` [PATCH v4 00/11] Add support for Kontron sl28cpld Lee Jones

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200604211039.12689-6-michael@walle.cc \
    --to=michael@walle.cc \
    --cc=andriy.shevchenko@linux.intel.com \
    --cc=bgolaszewski@baylibre.com \
    --cc=broonie@kernel.org \
    --cc=devicetree@vger.kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=jason@lakedaemon.net \
    --cc=jdelvare@suse.com \
    --cc=lee.jones@linaro.org \
    --cc=leoyang.li@nxp.com \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-hwmon@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pwm@vger.kernel.org \
    --cc=linux-watchdog@vger.kernel.org \
    --cc=linux@roeck-us.net \
    --cc=maz@kernel.org \
    --cc=robh+dt@kernel.org \
    --cc=shawnguo@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=thierry.reding@gmail.com \
    --cc=u.kleine-koenig@pengutronix.de \
    --cc=wim@linux-watchdog.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Watchdog Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-watchdog/0 linux-watchdog/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-watchdog linux-watchdog/ https://lore.kernel.org/linux-watchdog \
		linux-watchdog@vger.kernel.org
	public-inbox-index linux-watchdog

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-watchdog


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git