OpenWrt – Rev 4
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From fc8f96309c21c1bc3276427309cd7d361347d66e Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Mon, 7 Dec 2015 17:16:50 +0100
Subject: [PATCH 52/53] pwm: add mediatek support
Signed-off-by: John Crispin <blogic@openwrt.org>
---
drivers/pwm/Kconfig | 9 +++
drivers/pwm/Makefile | 1 +
drivers/pwm/pwm-mediatek.c | 173 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 183 insertions(+)
create mode 100644 drivers/pwm/pwm-mediatek.c
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -302,6 +302,15 @@ config PWM_MEDIATEK
To compile this driver as a module, choose M here: the module
will be called pwm-mediatek.
+config PWM_MEDIATEK_RAMIPS
+ tristate "Mediatek PWM support"
+ depends on RALINK && OF
+ help
+ Generic PWM framework driver for Mediatek ARM SoC.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-mxs.
+
config PWM_MXS
tristate "Freescale MXS PWM support"
depends on ARCH_MXS && OF
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_PWM_LPSS_PCI) += pwm-lpss-p
obj-$(CONFIG_PWM_LPSS_PLATFORM) += pwm-lpss-platform.o
obj-$(CONFIG_PWM_MESON) += pwm-meson.o
obj-$(CONFIG_PWM_MEDIATEK) += pwm-mediatek.o
+obj-$(CONFIG_PWM_MEDIATEK_RAMIPS) += pwm-mediatek-ramips.o
obj-$(CONFIG_PWM_MTK_DISP) += pwm-mtk-disp.o
obj-$(CONFIG_PWM_MXS) += pwm-mxs.o
obj-$(CONFIG_PWM_OMAP_DMTIMER) += pwm-omap-dmtimer.o
--- /dev/null
+++ b/drivers/pwm/pwm-mediatek-ramips.c
@@ -0,0 +1,173 @@
+/*
+ * 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/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define NUM_PWM 4
+
+/* 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
+
+/**
+ * struct mtk_pwm_chip - struct representing pwm chip
+ *
+ * @mmio_base: base address of pwm chip
+ * @chip: linux pwm chip representation
+ */
+struct mtk_pwm_chip {
+ void __iomem *mmio_base;
+ struct pwm_chip chip;
+};
+
+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 long offset)
+{
+ return ioread32(chip->mmio_base + 0x10 + (num * 0x40) + offset);
+}
+
+static inline void mtk_pwm_writel(struct mtk_pwm_chip *chip,
+ unsigned int num, unsigned long offset,
+ unsigned long val)
+{
+ iowrite32(val, chip->mmio_base + 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);
+ u32 resolution = 100 / 4;
+ u32 clkdiv = 0;
+
+ while (period_ns / resolution > 8191) {
+ clkdiv++;
+ resolution *= 2;
+ }
+
+ if (clkdiv > 7)
+ return -1;
+
+ 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 val;
+
+ val = ioread32(pc->mmio_base);
+ val |= BIT(pwm->hwpwm);
+ iowrite32(val, pc->mmio_base);
+
+ 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 val;
+
+ val = ioread32(pc->mmio_base);
+ val &= ~BIT(pwm->hwpwm);
+ iowrite32(val, pc->mmio_base);
+}
+
+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 *r;
+ int ret;
+
+ pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
+ if (!pc)
+ return -ENOMEM;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(pc->mmio_base))
+ return PTR_ERR(pc->mmio_base);
+
+ platform_set_drvdata(pdev, pc);
+
+ pc->chip.dev = &pdev->dev;
+ pc->chip.ops = &mtk_pwm_ops;
+ pc->chip.base = -1;
+ pc->chip.npwm = NUM_PWM;
+
+ ret = pwmchip_add(&pc->chip);
+ if (ret < 0)
+ dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+
+ return ret;
+}
+
+static int mtk_pwm_remove(struct platform_device *pdev)
+{
+ struct mtk_pwm_chip *pc = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < NUM_PWM; i++)
+ pwm_disable(&pc->chip.pwms[i]);
+
+ return pwmchip_remove(&pc->chip);
+}
+
+static const struct of_device_id mtk_pwm_of_match[] = {
+ { .compatible = "mediatek,mt7628-pwm" },
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, mtk_pwm_of_match);
+
+static struct platform_driver mtk_pwm_driver = {
+ .driver = {
+ .name = "mtk-pwm",
+ .owner = THIS_MODULE,
+ .of_match_table = mtk_pwm_of_match,
+ },
+ .probe = mtk_pwm_probe,
+ .remove = mtk_pwm_remove,
+};
+
+module_platform_driver(mtk_pwm_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
+MODULE_ALIAS("platform:mtk-pwm");
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