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[RFC,v5,6/9] drivers/pwm: Add Crystalcove (CRC) PWM driver

Message ID 1426177893-17945-7-git-send-email-shobhit.kumar@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Kumar, Shobhit March 12, 2015, 4:31 p.m. UTC
The Crystalcove PMIC controls PWM signals and this driver exports that
capability as a PWM chip driver. This is platform device implementtaion
of the drivers/mfd cell device for CRC PMIC

CC: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
---
 drivers/pwm/Kconfig   |   7 +++
 drivers/pwm/Makefile  |   1 +
 drivers/pwm/pwm-crc.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 169 insertions(+)
 create mode 100644 drivers/pwm/pwm-crc.c
diff mbox

Patch

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index b1541f4..954da3e 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -183,6 +183,13 @@  config PWM_LPC32XX
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-lpc32xx.
 
+config PWM_CRC
+	bool "Intel Crystalcove (CRC) PWM support"
+	depends on X86 && INTEL_SOC_PMIC
+	help
+	  Generic PWM framework driver for Crystalcove (CRC) PMIC based PWM
+	  control.
+
 config PWM_LPSS
 	tristate "Intel LPSS PWM support"
 	depends on X86
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
index ec50eb5..3d38fed 100644
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -35,3 +35,4 @@  obj-$(CONFIG_PWM_TIPWMSS)	+= pwm-tipwmss.o
 obj-$(CONFIG_PWM_TWL)		+= pwm-twl.o
 obj-$(CONFIG_PWM_TWL_LED)	+= pwm-twl-led.o
 obj-$(CONFIG_PWM_VT8500)	+= pwm-vt8500.o
+obj-$(CONFIG_PWM_CRC)		+= pwm-crc.o
diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
new file mode 100644
index 0000000..9dc169e
--- /dev/null
+++ b/drivers/pwm/pwm-crc.c
@@ -0,0 +1,161 @@ 
+/*
+ * pwm-crc.c - Intel Crystal Cove PWM Driver
+ *
+ * Copyright (C) 2015 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Author: Shobhit Kumar <shobhit.kumar@intel.com>
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/intel_soc_pmic.h>
+#include <linux/pwm.h>
+
+#define PWM0_CLK_DIV		0x4B
+#define  PWM_OUTPUT_ENABLE	(1<<7)
+#define  PWM_DIV_CLK_0		0x00 /* DIVIDECLK = BASECLK */
+#define  PWM_DIV_CLK_100	0x63 /* DIVIDECLK = BASECLK/100 */
+#define  PWM_DIV_CLK_128	0x7F /* DIVIDECLK = BASECLK/128 */
+
+#define PWM0_DUTY_CYCLE		0x4E
+#define BACKLIGHT_EN		0x51
+
+#define PWM_MAX_LEVEL		0xFF
+
+/**
+ * struct crystalcove_pwm - Crystal Cove PWM controller
+ * @chip: the abstract pwm_chip structure.
+ * @regmap: the regmap from the parent device.
+ */
+struct crystalcove_pwm {
+	struct pwm_chip chip;
+	struct platform_device *pdev;
+	struct regmap *regmap;
+};
+
+static inline struct crystalcove_pwm *to_crc_pwm(struct pwm_chip *pc)
+{
+	return container_of(pc, struct crystalcove_pwm, chip);
+}
+
+static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
+				  int clk_div, int duty_percent)
+{
+	struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
+	struct device *dev = &crc_pwm->pdev->dev;
+	int level;
+
+	dev_dbg(dev, "crc-pwm-config\n");
+
+	if (pwm->clk_div != clk_div) {
+		/* configure the clock divider */
+		if (clk_div > PWM_DIV_CLK_128)
+			clk_div = PWM_DIV_CLK_128;
+
+		regmap_write(crc_pwm->regmap, PWM0_CLK_DIV,
+					clk_div | PWM_OUTPUT_ENABLE);
+
+	}
+
+	/* change the pwm duty cycle */
+	level = (duty_percent * PWM_MAX_LEVEL) / 100;
+	regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level);
+
+	return 0;
+}
+
+static int crc_pwm_enable(struct pwm_chip *c, struct pwm_device *pwm)
+{
+	struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
+	struct device *dev = &crc_pwm->pdev->dev;
+
+	dev_dbg(dev, "crc-pwm-enable\n");
+
+	regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 1);
+
+	return 0;
+}
+
+static void crc_pwm_disable(struct pwm_chip *c, struct pwm_device *pwm)
+{
+	struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
+	struct device *dev = &crc_pwm->pdev->dev;
+
+	dev_dbg(dev, "crc-pwm-disable\n");
+
+	regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0);
+}
+
+static const struct pwm_ops crc_pwm_ops = {
+	.config_alternate = crc_pwm_config,
+	.enable = crc_pwm_enable,
+	.disable = crc_pwm_disable,
+	.owner = THIS_MODULE,
+};
+
+static int crystalcove_pwm_probe(struct platform_device *pdev)
+{
+	struct crystalcove_pwm *pwm;
+	int retval;
+	struct device *dev = pdev->dev.parent;
+	struct intel_soc_pmic *pmic = dev_get_drvdata(dev);
+
+	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+	if (!pwm)
+		return -ENOMEM;
+
+	pwm->chip.dev = &pdev->dev;
+	pwm->chip.ops = &crc_pwm_ops;
+	pwm->chip.base = -1;
+	pwm->chip.npwm = 1;
+
+	/* get the PMIC regmap */
+	pwm->regmap = pmic->regmap;
+
+	retval = pwmchip_add(&pwm->chip);
+	if (retval < 0)
+		return retval;
+
+	dev_dbg(&pdev->dev, "crc-pwm probe successful\n");
+	platform_set_drvdata(pdev, pwm);
+
+	return 0;
+}
+
+static int crystalcove_pwm_remove(struct platform_device *pdev)
+{
+	struct crystalcove_pwm *pwm = platform_get_drvdata(pdev);
+	int retval;
+
+	retval = pwmchip_remove(&pwm->chip);
+	if (retval < 0)
+		return retval;
+
+	dev_dbg(&pdev->dev, "crc-pwm driver removed\n");
+
+	return 0;
+}
+
+static struct platform_driver crystalcove_pwm_driver = {
+	.probe = crystalcove_pwm_probe,
+	.remove = crystalcove_pwm_remove,
+	.driver = {
+		.name = "crystal_cove_pwm",
+	},
+};
+
+module_platform_driver(crystalcove_pwm_driver);
+
+MODULE_AUTHOR("Shobhit Kumar <shobhit.kumar@intel.com>");
+MODULE_DESCRIPTION("Intel Crystal Cove PWM Driver");
+MODULE_LICENSE("GPL v2");