OpenE2K/linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
cae417b2a8
linux/drivers/pwm/pwm-mediatek.c
John Crispin 8cdc43afbb pwm: mediatek: Add MT7628 support 
Add support for MT7628. The SoC is legacy MIPS and hence has no complex
clock tree. This patch add an extra flag to the SoC specific data
indicating, that no clocks are present.

Signed-off-by: John Crispin <john@phrozen.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-08-20 11:36:07 +02:00

326 lines
7.6 KiB
C
Raw Blame History

/*
* Mediatek Pulse Width Modulator driver
*
* Copyright (C) 2015 John Crispin <blogic@openwrt.org>
* Copyright (C) 2017 Zhi Mao <zhi.mao@mediatek.com>
*
* 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/of_device.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 PWM45DWIDTH_FIXUP 0x30
#define PWMTHRES 0x30
#define PWM45THRES_FIXUP 0x34
#define PWM_CLK_DIV_MAX 7
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_PWM6,
MTK_CLK_PWM7,
MTK_CLK_PWM8,
MTK_CLK_MAX,
};
static const char * const mtk_pwm_clk_name[MTK_CLK_MAX] = {
"main", "top", "pwm1", "pwm2", "pwm3", "pwm4", "pwm5", "pwm6", "pwm7",
"pwm8"
};
struct mtk_pwm_platform_data {
unsigned int num_pwms;
bool pwm45_fixup;
bool has_clks;
};
/**
* 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];
const struct mtk_pwm_platform_data *soc;
};
static const unsigned int mtk_pwm_reg_offset[] = {
0x0010, 0x0050, 0x0090, 0x00d0, 0x0110, 0x0150, 0x0190, 0x0220
};
static inline struct mtk_pwm_chip *to_mtk_pwm_chip(struct pwm_chip *chip)
{
return container_of(chip, struct mtk_pwm_chip, chip);
}
static int mtk_pwm_clk_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
int ret;
if (!pc->soc->has_clks)
return 0;
ret = clk_prepare_enable(pc->clks[MTK_CLK_TOP]);
if (ret < 0)
return ret;
ret = clk_prepare_enable(pc->clks[MTK_CLK_MAIN]);
if (ret < 0)
goto disable_clk_top;
ret = clk_prepare_enable(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
if (ret < 0)
goto disable_clk_main;
return 0;
disable_clk_main:
clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]);
disable_clk_top:
clk_disable_unprepare(pc->clks[MTK_CLK_TOP]);
return ret;
}
static void mtk_pwm_clk_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct mtk_pwm_chip *pc = to_mtk_pwm_chip(chip);
if (!pc->soc->has_clks)
return;
clk_disable_unprepare(pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]);
clk_disable_unprepare(pc->clks[MTK_CLK_MAIN]);
clk_disable_unprepare(pc->clks[MTK_CLK_TOP]);
}
static inline u32 mtk_pwm_readl(struct mtk_pwm_chip *chip, unsigned int num,
unsigned int offset)
{
return readl(chip->regs + mtk_pwm_reg_offset[num] + offset);
}
static inline void mtk_pwm_writel(struct mtk_pwm_chip *chip,
unsigned int num, unsigned int offset,
u32 value)
{
writel(value, chip->regs + mtk_pwm_reg_offset[num] + 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 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
reg_thres = PWMTHRES;
u64 resolution;
int ret;
ret = mtk_pwm_clk_enable(chip, pwm);
if (ret < 0)
return ret;
/* Using resolution in picosecond gets accuracy higher */
resolution = (u64)NSEC_PER_SEC * 1000;
do_div(resolution, clk_get_rate(clk));
cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
while (cnt_period > 8191) {
resolution *= 2;
clkdiv++;
cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000,
resolution);
}
if (clkdiv > PWM_CLK_DIV_MAX) {
mtk_pwm_clk_disable(chip, pwm);
dev_err(chip->dev, "period %d not supported\n", period_ns);
return -EINVAL;
}
if (pc->soc->pwm45_fixup && pwm->hwpwm > 2) {
/*
* PWM[4,5] has distinct offset for PWMDWIDTH and PWMTHRES
* from the other PWMs on MT7623.
*/
reg_width = PWM45DWIDTH_FIXUP;
reg_thres = PWM45THRES_FIXUP;
}
cnt_duty = DIV_ROUND_CLOSEST_ULL((u64)duty_ns * 1000, resolution);
mtk_pwm_writel(pc, pwm->hwpwm, PWMCON, BIT(15) | clkdiv);
mtk_pwm_writel(pc, pwm->hwpwm, reg_width, cnt_period);
mtk_pwm_writel(pc, pwm->hwpwm, reg_thres, cnt_duty);
mtk_pwm_clk_disable(chip, pwm);
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 = mtk_pwm_clk_enable(chip, pwm);
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);
mtk_pwm_clk_disable(chip, pwm);
}
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)
{
const struct mtk_pwm_platform_data *data;
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;
data = of_device_get_match_data(&pdev->dev);
if (data == NULL)
return -EINVAL;
pc->soc = data;
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 < data->num_pwms + 2 && pc->soc->has_clks; i++) {
pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]);
if (IS_ERR(pc->clks[i])) {
dev_err(&pdev->dev, "clock: %s fail: %ld\n",
mtk_pwm_clk_name[i], PTR_ERR(pc->clks[i]));
return PTR_ERR(pc->clks[i]);
}
}
platform_set_drvdata(pdev, pc);
pc->chip.dev = &pdev->dev;
pc->chip.ops = &mtk_pwm_ops;
pc->chip.base = -1;
pc->chip.npwm = data->num_pwms;
ret = pwmchip_add(&pc->chip);
if (ret < 0) {
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
return ret;
}
return 0;
}
static int mtk_pwm_remove(struct platform_device *pdev)
{
struct mtk_pwm_chip *pc = platform_get_drvdata(pdev);
return pwmchip_remove(&pc->chip);
}
static const struct mtk_pwm_platform_data mt2712_pwm_data = {
.num_pwms = 8,
.pwm45_fixup = false,
.has_clks = true,
};
static const struct mtk_pwm_platform_data mt7622_pwm_data = {
.num_pwms = 6,
.pwm45_fixup = false,
.has_clks = true,
};
static const struct mtk_pwm_platform_data mt7623_pwm_data = {
.num_pwms = 5,
.pwm45_fixup = true,
.has_clks = true,
};
static const struct mtk_pwm_platform_data mt7628_pwm_data = {
.num_pwms = 4,
.pwm45_fixup = true,
.has_clks = false,
};
static const struct of_device_id mtk_pwm_of_match[] = {
{ .compatible = "mediatek,mt2712-pwm", .data = &mt2712_pwm_data },
{ .compatible = "mediatek,mt7622-pwm", .data = &mt7622_pwm_data },
{ .compatible = "mediatek,mt7623-pwm", .data = &mt7623_pwm_data },
{ .compatible = "mediatek,mt7628-pwm", .data = &mt7628_pwm_data },
{ },
};
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_LICENSE("GPL");
Reference in New Issue View Git Blame Copy Permalink