1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-crc.c b/drivers/pwm/pwm-crc.c
new file mode 100644
index 000000000000..7101c7020bf4
--- /dev/null
+++ b/drivers/pwm/pwm-crc.c
@@ -0,0 +1,143 @@
+/*
+ * 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/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      BIT(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
+
+#define PWM_BASE_CLK            6000000  /* 6 MHz */
+#define PWM_MAX_PERIOD_NS       21333    /* 46.875KHz */
+
+/**
+ * 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 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_enable(struct pwm_chip *c, struct pwm_device *pwm)
+{
+        struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
+
+        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);
+
+        regmap_write(crc_pwm->regmap, BACKLIGHT_EN, 0);
+}
+
+static int crc_pwm_config(struct pwm_chip *c, struct pwm_device *pwm,
+                          int duty_ns, int period_ns)
+{
+        struct crystalcove_pwm *crc_pwm = to_crc_pwm(c);
+        struct device *dev = crc_pwm->chip.dev;
+        int level;
+
+        if (period_ns > PWM_MAX_PERIOD_NS) {
+                dev_err(dev, "un-supported period_ns\n");
+                return -EINVAL;
+        }
+
+        if (pwm->period != period_ns) {
+                int clk_div;
+
+                /* changing the clk divisor, need to disable fisrt */
+                crc_pwm_disable(c, pwm);
+                clk_div = PWM_BASE_CLK * period_ns / NSEC_PER_SEC;
+
+                regmap_write(crc_pwm->regmap, PWM0_CLK_DIV,
+                                        clk_div | PWM_OUTPUT_ENABLE);
+
+                /* enable back */
+                crc_pwm_enable(c, pwm);
+        }
+
+        /* change the pwm duty cycle */
+        level = duty_ns * PWM_MAX_LEVEL / period_ns;
+        regmap_write(crc_pwm->regmap, PWM0_DUTY_CYCLE, level);
+
+        return 0;
+}
+
+static const struct pwm_ops crc_pwm_ops = {
+        .config = crc_pwm_config,
+        .enable = crc_pwm_enable,
+        .disable = crc_pwm_disable,
+};
+
+static int crystalcove_pwm_probe(struct platform_device *pdev)
+{
+        struct crystalcove_pwm *pwm;
+        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;
+
+        platform_set_drvdata(pdev, pwm);
+
+        return pwmchip_add(&pwm->chip);
+}
+
+static int crystalcove_pwm_remove(struct platform_device *pdev)
+{
+        struct crystalcove_pwm *pwm = platform_get_drvdata(pdev);
+
+        return pwmchip_remove(&pwm->chip);
+}
+
+static struct platform_driver crystalcove_pwm_driver = {
+        .probe = crystalcove_pwm_probe,
+        .remove = crystalcove_pwm_remove,
+        .driver = {
+                .name = "crystal_cove_pwm",
+        },
+};
+
+builtin_platform_driver(crystalcove_pwm_driver);