1 files changed, 249 insertions, 0 deletions

diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c
new file mode 100644
index 000000000000..476171a768d6
--- /dev/null
+++ b/drivers/pwm/pwm-img.c
@@ -0,0 +1,249 @@
+/*
+ * Imagination Technologies Pulse Width Modulator driver
+ *
+ * Copyright (c) 2014-2015, Imagination Technologies
+ *
+ * Based on drivers/pwm/pwm-tegra.c, Copyright (c) 2010, NVIDIA Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* PWM registers */
+#define PWM_CTRL_CFG                            0x0000
+#define PWM_CTRL_CFG_NO_SUB_DIV                 0
+#define PWM_CTRL_CFG_SUB_DIV0                   1
+#define PWM_CTRL_CFG_SUB_DIV1                   2
+#define PWM_CTRL_CFG_SUB_DIV0_DIV1              3
+#define PWM_CTRL_CFG_DIV_SHIFT(ch)              ((ch) * 2 + 4)
+#define PWM_CTRL_CFG_DIV_MASK                   0x3
+
+#define PWM_CH_CFG(ch)                          (0x4 + (ch) * 4)
+#define PWM_CH_CFG_TMBASE_SHIFT                 0
+#define PWM_CH_CFG_DUTY_SHIFT                   16
+
+#define PERIP_PWM_PDM_CONTROL                   0x0140
+#define PERIP_PWM_PDM_CONTROL_CH_MASK           0x1
+#define PERIP_PWM_PDM_CONTROL_CH_SHIFT(ch)      ((ch) * 4)
+
+#define MAX_TMBASE_STEPS                        65536
+
+struct img_pwm_chip {
+        struct device   *dev;
+        struct pwm_chip chip;
+        struct clk      *pwm_clk;
+        struct clk      *sys_clk;
+        void __iomem    *base;
+        struct regmap   *periph_regs;
+};
+
+static inline struct img_pwm_chip *to_img_pwm_chip(struct pwm_chip *chip)
+{
+        return container_of(chip, struct img_pwm_chip, chip);
+}
+
+static inline void img_pwm_writel(struct img_pwm_chip *chip,
+                                  u32 reg, u32 val)
+{
+        writel(val, chip->base + reg);
+}
+
+static inline u32 img_pwm_readl(struct img_pwm_chip *chip,
+                                         u32 reg)
+{
+        return readl(chip->base + reg);
+}
+
+static int img_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+                          int duty_ns, int period_ns)
+{
+        u32 val, div, duty, timebase;
+        unsigned long mul, output_clk_hz, input_clk_hz;
+        struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);
+
+        input_clk_hz = clk_get_rate(pwm_chip->pwm_clk);
+        output_clk_hz = DIV_ROUND_UP(NSEC_PER_SEC, period_ns);
+
+        mul = DIV_ROUND_UP(input_clk_hz, output_clk_hz);
+        if (mul <= MAX_TMBASE_STEPS) {
+                div = PWM_CTRL_CFG_NO_SUB_DIV;
+                timebase = DIV_ROUND_UP(mul, 1);
+        } else if (mul <= MAX_TMBASE_STEPS * 8) {
+                div = PWM_CTRL_CFG_SUB_DIV0;
+                timebase = DIV_ROUND_UP(mul, 8);
+        } else if (mul <= MAX_TMBASE_STEPS * 64) {
+                div = PWM_CTRL_CFG_SUB_DIV1;
+                timebase = DIV_ROUND_UP(mul, 64);
+        } else if (mul <= MAX_TMBASE_STEPS * 512) {
+                div = PWM_CTRL_CFG_SUB_DIV0_DIV1;
+                timebase = DIV_ROUND_UP(mul, 512);
+        } else if (mul > MAX_TMBASE_STEPS * 512) {
+                dev_err(chip->dev,
+                        "failed to configure timebase steps/divider value\n");
+                return -EINVAL;
+        }
+
+        duty = DIV_ROUND_UP(timebase * duty_ns, period_ns);
+
+        val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
+        val &= ~(PWM_CTRL_CFG_DIV_MASK << PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm));
+        val |= (div & PWM_CTRL_CFG_DIV_MASK) <<
+                PWM_CTRL_CFG_DIV_SHIFT(pwm->hwpwm);
+        img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
+
+        val = (duty << PWM_CH_CFG_DUTY_SHIFT) |
+              (timebase << PWM_CH_CFG_TMBASE_SHIFT);
+        img_pwm_writel(pwm_chip, PWM_CH_CFG(pwm->hwpwm), val);
+
+        return 0;
+}
+
+static int img_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+        u32 val;
+        struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);
+
+        val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
+        val |= BIT(pwm->hwpwm);
+        img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
+
+        regmap_update_bits(pwm_chip->periph_regs, PERIP_PWM_PDM_CONTROL,
+                           PERIP_PWM_PDM_CONTROL_CH_MASK <<
+                           PERIP_PWM_PDM_CONTROL_CH_SHIFT(pwm->hwpwm), 0);
+
+        return 0;
+}
+
+static void img_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+        u32 val;
+        struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip);
+
+        val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
+        val &= ~BIT(pwm->hwpwm);
+        img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
+}
+
+static const struct pwm_ops img_pwm_ops = {
+        .config = img_pwm_config,
+        .enable = img_pwm_enable,
+        .disable = img_pwm_disable,
+        .owner = THIS_MODULE,
+};
+
+static int img_pwm_probe(struct platform_device *pdev)
+{
+        int ret;
+        struct resource *res;
+        struct img_pwm_chip *pwm;
+
+        pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
+        if (!pwm)
+                return -ENOMEM;
+
+        pwm->dev = &pdev->dev;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        pwm->base = devm_ioremap_resource(&pdev->dev, res);
+        if (IS_ERR(pwm->base))
+                return PTR_ERR(pwm->base);
+
+        pwm->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+                                                           "img,cr-periph");
+        if (IS_ERR(pwm->periph_regs))
+                return PTR_ERR(pwm->periph_regs);
+
+        pwm->sys_clk = devm_clk_get(&pdev->dev, "sys");
+        if (IS_ERR(pwm->sys_clk)) {
+                dev_err(&pdev->dev, "failed to get system clock\n");
+                return PTR_ERR(pwm->sys_clk);
+        }
+
+        pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm");
+        if (IS_ERR(pwm->pwm_clk)) {
+                dev_err(&pdev->dev, "failed to get pwm clock\n");
+                return PTR_ERR(pwm->pwm_clk);
+        }
+
+        ret = clk_prepare_enable(pwm->sys_clk);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "could not prepare or enable sys clock\n");
+                return ret;
+        }
+
+        ret = clk_prepare_enable(pwm->pwm_clk);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "could not prepare or enable pwm clock\n");
+                goto disable_sysclk;
+        }
+
+        pwm->chip.dev = &pdev->dev;
+        pwm->chip.ops = &img_pwm_ops;
+        pwm->chip.base = -1;
+        pwm->chip.npwm = 4;
+
+        ret = pwmchip_add(&pwm->chip);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);
+                goto disable_pwmclk;
+        }
+
+        platform_set_drvdata(pdev, pwm);
+        return 0;
+
+disable_pwmclk:
+        clk_disable_unprepare(pwm->pwm_clk);
+disable_sysclk:
+        clk_disable_unprepare(pwm->sys_clk);
+        return ret;
+}
+
+static int img_pwm_remove(struct platform_device *pdev)
+{
+        struct img_pwm_chip *pwm_chip = platform_get_drvdata(pdev);
+        u32 val;
+        unsigned int i;
+
+        for (i = 0; i < pwm_chip->chip.npwm; i++) {
+                val = img_pwm_readl(pwm_chip, PWM_CTRL_CFG);
+                val &= ~BIT(i);
+                img_pwm_writel(pwm_chip, PWM_CTRL_CFG, val);
+        }
+
+        clk_disable_unprepare(pwm_chip->pwm_clk);
+        clk_disable_unprepare(pwm_chip->sys_clk);
+
+        return pwmchip_remove(&pwm_chip->chip);
+}
+
+static const struct of_device_id img_pwm_of_match[] = {
+        { .compatible = "img,pistachio-pwm", },
+        { }
+};
+MODULE_DEVICE_TABLE(of, img_pwm_of_match);
+
+static struct platform_driver img_pwm_driver = {
+        .driver = {
+                .name = "img-pwm",
+                .of_match_table = img_pwm_of_match,
+        },
+        .probe = img_pwm_probe,
+        .remove = img_pwm_remove,
+};
+module_platform_driver(img_pwm_driver);
+
+MODULE_AUTHOR("Sai Masarapu <Sai.Masarapu@imgtec.com>");
+MODULE_DESCRIPTION("Imagination Technologies PWM DAC driver");
+MODULE_LICENSE("GPL v2");