ramips: add mt7628 pwm driver

Signed-off-by: John Crispin <blogic@openwrt.org>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@46953 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/target/linux/ramips/patches-3.18/0065-mt7628-pww.patch b/target/linux/ramips/patches-3.18/0065-mt7628-pww.patch
new file mode 100644 (file)
index 0000000..4b82a7e
--- /dev/null
+++ b/target/linux/ramips/patches-3.18/0065-mt7628-pww.patch
@@ -0,0 +1,204 @@
+--- a/drivers/pwm/Kconfig
++++ b/drivers/pwm/Kconfig
+@@ -177,6 +177,15 @@
+         To compile this driver as a module, choose M here: the module
+         will be called pwm-lpss-platform.
+ 
++config PWM_MEDIATEK
++      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
+@@ -15,6 +15,7 @@
+ obj-$(CONFIG_PWM_LPSS)                += pwm-lpss.o
+ obj-$(CONFIG_PWM_LPSS_PCI)    += pwm-lpss-pci.o
+ obj-$(CONFIG_PWM_LPSS_PLATFORM)       += pwm-lpss-platform.o
++obj-$(CONFIG_PWM_MEDIATEK)    += pwm-mediatek.o
+ obj-$(CONFIG_PWM_MXS)         += pwm-mxs.o
+ obj-$(CONFIG_PWM_PCA9685)     += pwm-pca9685.o
+ obj-$(CONFIG_PWM_PUV3)                += pwm-puv3.o
+--- /dev/null
++++ b/drivers/pwm/pwm-mediatek.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");