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 <[email protected]>
Cc: Linus Walleij <[email protected]>
Cc: Alexandre Courbot <[email protected]>
Cc: Thierry Reding <[email protected]>
Signed-off-by: Shobhit Kumar <[email protected]>
---
 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 --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 <[email protected]>
+ */
+
+#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 <[email protected]>");
+MODULE_DESCRIPTION("Intel Crystal Cove PWM Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.1.0

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