Release 4.8 drivers/pwm/pwm-lpss.c
/*
* Intel Low Power Subsystem PWM controller driver
*
* Copyright (C) 2014, Intel Corporation
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
* Author: Chew Kean Ho <kean.ho.chew@intel.com>
* Author: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@intel.com>
* Author: Chew Chiau Ee <chiau.ee.chew@intel.com>
* Author: Alan Cox <alan@linux.intel.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/time.h>
#include "pwm-lpss.h"
#define PWM 0x00000000
#define PWM_ENABLE BIT(31)
#define PWM_SW_UPDATE BIT(30)
#define PWM_BASE_UNIT_SHIFT 8
#define PWM_ON_TIME_DIV_MASK 0x000000ff
/* Size of each PWM register space if multiple */
#define PWM_SIZE 0x400
struct pwm_lpss_chip {
struct pwm_chip chip;
void __iomem *regs;
const struct pwm_lpss_boardinfo *info;
};
/* BayTrail */
const struct pwm_lpss_boardinfo pwm_lpss_byt_info = {
.clk_rate = 25000000,
.npwm = 1,
.base_unit_bits = 16,
};
EXPORT_SYMBOL_GPL(pwm_lpss_byt_info);
/* Braswell */
const struct pwm_lpss_boardinfo pwm_lpss_bsw_info = {
.clk_rate = 19200000,
.npwm = 1,
.base_unit_bits = 16,
};
EXPORT_SYMBOL_GPL(pwm_lpss_bsw_info);
/* Broxton */
const struct pwm_lpss_boardinfo pwm_lpss_bxt_info = {
.clk_rate = 19200000,
.npwm = 4,
.base_unit_bits = 22,
};
EXPORT_SYMBOL_GPL(pwm_lpss_bxt_info);
static inline struct pwm_lpss_chip *to_lpwm(struct pwm_chip *chip)
{
return container_of(chip, struct pwm_lpss_chip, chip);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 25 | 100.00% | 1 | 100.00% |
| Total | 25 | 100.00% | 1 | 100.00% |
static inline u32 pwm_lpss_read(const struct pwm_device *pwm)
{
struct pwm_lpss_chip *lpwm = to_lpwm(pwm->chip);
return readl(lpwm->regs + pwm->hwpwm * PWM_SIZE + PWM);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 41 | 100.00% | 1 | 100.00% |
| Total | 41 | 100.00% | 1 | 100.00% |
static inline void pwm_lpss_write(const struct pwm_device *pwm, u32 value)
{
struct pwm_lpss_chip *lpwm = to_lpwm(pwm->chip);
writel(value, lpwm->regs + pwm->hwpwm * PWM_SIZE + PWM);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 45 | 100.00% | 1 | 100.00% |
| Total | 45 | 100.00% | 1 | 100.00% |
static void pwm_lpss_update(struct pwm_device *pwm)
{
pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_SW_UPDATE);
/* Give it some time to propagate */
usleep_range(10, 50);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 31 | 100.00% | 1 | 100.00% |
| Total | 31 | 100.00% | 1 | 100.00% |
static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct pwm_lpss_chip *lpwm = to_lpwm(chip);
unsigned long long on_time_div;
unsigned long c = lpwm->info->clk_rate, base_unit_range;
unsigned long long base_unit, freq = NSEC_PER_SEC;
u32 ctrl;
do_div(freq, period_ns);
/*
* The equation is:
* base_unit = round(base_unit_range * freq / c)
*/
base_unit_range = BIT(lpwm->info->base_unit_bits);
freq *= base_unit_range;
base_unit = DIV_ROUND_CLOSEST_ULL(freq, c);
if (duty_ns <= 0)
duty_ns = 1;
on_time_div = 255ULL * duty_ns;
do_div(on_time_div, period_ns);
on_time_div = 255ULL - on_time_div;
pm_runtime_get_sync(chip->dev);
ctrl = pwm_lpss_read(pwm);
ctrl &= ~PWM_ON_TIME_DIV_MASK;
ctrl &= ~((base_unit_range - 1) << PWM_BASE_UNIT_SHIFT);
base_unit &= (base_unit_range - 1);
ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT;
ctrl |= on_time_div;
pwm_lpss_write(pwm, ctrl);
/*
* If the PWM is already enabled we need to notify the hardware
* about the change by setting PWM_SW_UPDATE.
*/
if (pwm_is_enabled(pwm))
pwm_lpss_update(pwm);
pm_runtime_put(chip->dev);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 143 | 69.76% | 4 | 50.00% |
| qipeng zha | qipeng zha | 50 | 24.39% | 2 | 25.00% |
| andy shevchenko | andy shevchenko | 6 | 2.93% | 1 | 12.50% |
| dan o donovan | dan o donovan | 6 | 2.93% | 1 | 12.50% |
| Total | 205 | 100.00% | 8 | 100.00% |
static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
pm_runtime_get_sync(chip->dev);
/*
* Hardware must first see PWM_SW_UPDATE before the PWM can be
* enabled.
*/
pwm_lpss_update(pwm);
pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 37 | 84.09% | 3 | 75.00% |
| qipeng zha | qipeng zha | 7 | 15.91% | 1 | 25.00% |
| Total | 44 | 100.00% | 4 | 100.00% |
static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);
pm_runtime_put(chip->dev);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 29 | 80.56% | 2 | 66.67% |
| qipeng zha | qipeng zha | 7 | 19.44% | 1 | 33.33% |
| Total | 36 | 100.00% | 3 | 100.00% |
static const struct pwm_ops pwm_lpss_ops = {
.config = pwm_lpss_config,
.enable = pwm_lpss_enable,
.disable = pwm_lpss_disable,
.owner = THIS_MODULE,
};
struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r,
const struct pwm_lpss_boardinfo *info)
{
struct pwm_lpss_chip *lpwm;
unsigned long c;
int ret;
lpwm = devm_kzalloc(dev, sizeof(*lpwm), GFP_KERNEL);
if (!lpwm)
return ERR_PTR(-ENOMEM);
lpwm->regs = devm_ioremap_resource(dev, r);
if (IS_ERR(lpwm->regs))
return ERR_CAST(lpwm->regs);
lpwm->info = info;
c = lpwm->info->clk_rate;
if (!c)
return ERR_PTR(-EINVAL);
lpwm->chip.dev = dev;
lpwm->chip.ops = &pwm_lpss_ops;
lpwm->chip.base = -1;
lpwm->chip.npwm = info->npwm;
ret = pwmchip_add(&lpwm->chip);
if (ret) {
dev_err(dev, "failed to add PWM chip: %d\n", ret);
return ERR_PTR(ret);
}
return lpwm;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 128 | 68.82% | 2 | 33.33% |
| alan cox | alan cox | 29 | 15.59% | 1 | 16.67% |
| andy shevchenko | andy shevchenko | 24 | 12.90% | 1 | 16.67% |
| thierry reding | thierry reding | 4 | 2.15% | 1 | 16.67% |
| qipeng zha | qipeng zha | 1 | 0.54% | 1 | 16.67% |
| Total | 186 | 100.00% | 6 | 100.00% |
EXPORT_SYMBOL_GPL(pwm_lpss_probe);
int pwm_lpss_remove(struct pwm_lpss_chip *lpwm)
{
return pwmchip_remove(&lpwm->chip);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 17 | 89.47% | 1 | 50.00% |
| alan cox | alan cox | 2 | 10.53% | 1 | 50.00% |
| Total | 19 | 100.00% | 2 | 100.00% |
EXPORT_SYMBOL_GPL(pwm_lpss_remove);
MODULE_DESCRIPTION("PWM driver for Intel LPSS");
MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
MODULE_LICENSE("GPL v2");
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| mika westerberg | mika westerberg | 624 | 74.64% | 5 | 31.25% |
| qipeng zha | qipeng zha | 91 | 10.89% | 2 | 12.50% |
| alan cox | alan cox | 52 | 6.22% | 2 | 12.50% |
| andy shevchenko | andy shevchenko | 49 | 5.86% | 2 | 12.50% |
| thierry reding | thierry reding | 7 | 0.84% | 2 | 12.50% |
| dan o donovan | dan o donovan | 6 | 0.72% | 1 | 6.25% |
| julia lawall | julia lawall | 6 | 0.72% | 1 | 6.25% |
| heikki krogerus | heikki krogerus | 1 | 0.12% | 1 | 6.25% |
| Total | 836 | 100.00% | 16 | 100.00% |
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.