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authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-09 15:34:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-09 15:34:20 -0700
commitecc721a72c121e8b641d68efd24a225abedb9a30 (patch)
tree15d514f0c374292218a52dcc24a82d7c55bcfcfc /drivers/pwm/pwm-mediatek.c
parent28b47809b2171a6cfbab839936b24280639c9f85 (diff)
parent97512ceafaacf8cdb96d6a36ae55e8335c0a9e55 (diff)
Merge tag 'pwm/for-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding: "Adds a new driver for the PWM controller found on MediaTek SoCs and extends support for the Atmel PWM controller to include the SAMA5D2. Some existing drivers have been migrated to the atomic API and a few others see miscellaneous improvements" * tag 'pwm/for-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: pwm: tegra: Read PWM clock source rate in driver init pwm: pca9685: Fix GPIO-only operation pwm: mediatek: Don't explicitly set .owner pwm: tegra: Avoid potential overflow for short periods pwm: tegra: Add support to configure pin state in suspends/resume pwm: tegra: Add DT binding details to configure pin in suspends/resume pwm: tegra: Increase precision in PWM rate calculation pwm: tegra: Use DIV_ROUND_CLOSEST_ULL() instead of local implementation pwm: Add MediaTek PWM support dt-bindings: pwm: Add MediaTek PWM bindings pwm: atmel: Enable PWM on sama5d2 pwm: atmel: Switch to atomic PWM pwm: atmel-hlcdc: Implement the suspend/resume hooks pwm: atmel-hlcdc: Convert to the atomic PWM API
Diffstat (limited to 'drivers/pwm/pwm-mediatek.c')
-rw-r--r--drivers/pwm/pwm-mediatek.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
new file mode 100644
index 000000000000..5c11bc708a3c
--- /dev/null
+++ b/drivers/pwm/pwm-mediatek.c
@@ -0,0 +1,219 @@
+/*
+ * Mediatek Pulse Width Modulator driver
+ *
+ * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+/* PWM registers and bits definitions */
+#define PWMCON 0x00
+#define PWMHDUR 0x04
+#define PWMLDUR 0x08
+#define PWMGDUR 0x0c
+#define PWMWAVENUM 0x28
+#define PWMDWIDTH 0x2c
+#define PWMTHRES 0x30
+
+enum {
+ MTK_CLK_MAIN = 0,
+ MTK_CLK_TOP,
+ MTK_CLK_PWM1,
+ MTK_CLK_PWM2,
+ MTK_CLK_PWM3,
+ MTK_CLK_PWM4,
+ MTK_CLK_PWM5,
+ MTK_CLK_MAX,
+};
+
+static const char * const mtk_pwm_clk_name[] = {
+ "main", "top", "pwm1", "pwm2", "pwm3", "pwm4", "pwm5"
+};
+
+/**
+ * struct mtk_pwm_chip - struct representing PWM chip
+ * @chip: linux PWM chip representation
+ * @regs: base address of PWM chip
+ * @clks: list of clocks
+ */
+struct mtk_pwm_chip {
+ struct pwm_chip chip;
+ void __iomem *regs;
+ struct clk *clks[MTK_CLK_MAX];
+};
+
+static inline struct mtk_pwm_chip *to_mtk_pwm_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct mtk_pwm_chip, chip);
+}
+
+static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num,
+ unsigned int offset)
+{
+ return readl(chip->regs + 0x10 + (num * 0x40) + offset);
+}
+
+static inline void mtk_pwm_writel(struct mtk_pwm_chip *chip,
+ unsigned int num, unsigned int offset,
+ u32 value)
+{
+ writel(value, chip->regs + 0x10 + (num * 0x40) + offset);
+}
+
+static int mtk_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+ struct clk *clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm];
+ u32 resolution, clkdiv = 0;
+
+ resolution = NSEC_PER_SEC / clk_get_rate(clk);
+
+ while (period_ns / resolution > 8191) {
+ resolution *= 2;
+ clkdiv++;
+ }
+
+ if (clkdiv > 7)
+ return -EINVAL;
+
+ mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | BIT(3) | clkdiv);
+ mtk_pwm_writel(pc, pwm->hwpwm, PWMDWIDTH, period_ns / resolution);
+ mtk_pwm_writel(pc, pwm->hwpwm, PWMTHRES, duty_ns / resolution);
+
+ return 0;
+}
+
+static int mtk_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+ u32 value;
+ int ret;
+
+ ret = clk_prepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
+ if (ret < 0)
+ return ret;
+
+ value = readl(pc->regs);
+ value |= BIT(pwm->hwpwm);
+ writel(value, pc->regs);
+
+ return 0;
+}
+
+static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
+ u32 value;
+
+ value = readl(pc->regs);
+ value &= ~BIT(pwm->hwpwm);
+ writel(value, pc->regs);
+
+ clk_unprepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
+}
+
+static const struct pwm_ops mtk_pwm_ops = {
+ .config = mtk_pwm_config,
+ .enable = mtk_pwm_enable,
+ .disable = mtk_pwm_disable,
+ .owner = THIS_MODULE,
+};
+
+static int mtk_pwm_probe(struct platform_device *pdev)
+{
+ struct mtk_pwm_chip *pc;
+ struct resource *res;
+ unsigned int i;
+ int ret;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pc->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(pc->regs))
+ return PTR_ERR(pc->regs);
+
+ for (i = 0; i < MTK_CLK_MAX; i++) {
+ pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]);
+ if (IS_ERR(pc->clks[i]))
+ return PTR_ERR(pc->clks[i]);
+ }
+
+ ret = clk_prepare(pc->clks[MTK_CLK_TOP]);
+ if (ret < 0)
+ return ret;
+
+ ret = clk_prepare(pc->clks[MTK_CLK_MAIN]);
+ if (ret < 0)
+ goto disable_clk_top;
+
+ platform_set_drvdata(pdev, pc);
+
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = &mtk_pwm_ops;
+ pc->chip.base = -1;
+ pc->chip.npwm = 5;
+
+ ret = pwmchip_add(&pc->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+ goto disable_clk_main;
+ }
+
+ return 0;
+
+disable_clk_main:
+ clk_unprepare(pc->clks[MTK_CLK_MAIN]);
+disable_clk_top:
+ clk_unprepare(pc->clks[MTK_CLK_TOP]);
+
+ return ret;
+}
+
+static int mtk_pwm_remove(struct platform_device *pdev)
+{
+ struct mtk_pwm_chip *pc = platform_get_drvdata(pdev);
+ unsigned int i;
+
+ for (i = 0; i < pc->chip.npwm; i++)
+ pwm_disable(&pc->chip.pwms[i]);
+
+ return pwmchip_remove(&pc->chip);
+}
+
+static const struct of_device_id mtk_pwm_of_match[] = {
+ { .compatible = "mediatek,mt7623-pwm" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mtk_pwm_of_match);
+
+static struct platform_driver mtk_pwm_driver = {
+ .driver = {
+ .name = "mtk-pwm",
+ .of_match_table = mtk_pwm_of_match,
+ },
+ .probe = mtk_pwm_probe,
+ .remove = mtk_pwm_remove,
+};
+module_platform_driver(mtk_pwm_driver);
+
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
+MODULE_ALIAS("platform:mtk-pwm");
+MODULE_LICENSE("GPL");