forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
219 lines
5.3 KiB
219 lines
5.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* PWM framework driver for Cirrus Logic EP93xx |
|
* |
|
* Copyright (c) 2009 Matthieu Crapet <[email protected]> |
|
* Copyright (c) 2009, 2013 H Hartley Sweeten <[email protected]> |
|
* |
|
* EP9301/02 have only one channel: |
|
* platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14) |
|
* |
|
* EP9307 has only one channel: |
|
* platform device ep93xx-pwm.0 - PWMOUT |
|
* |
|
* EP9312/15 have two channels: |
|
* platform device ep93xx-pwm.0 - PWMOUT |
|
* platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14) |
|
*/ |
|
|
|
#include <linux/module.h> |
|
#include <linux/platform_device.h> |
|
#include <linux/slab.h> |
|
#include <linux/clk.h> |
|
#include <linux/err.h> |
|
#include <linux/io.h> |
|
#include <linux/pwm.h> |
|
|
|
#include <asm/div64.h> |
|
|
|
#include <linux/soc/cirrus/ep93xx.h> /* for ep93xx_pwm_{acquire,release}_gpio() */ |
|
|
|
#define EP93XX_PWMx_TERM_COUNT 0x00 |
|
#define EP93XX_PWMx_DUTY_CYCLE 0x04 |
|
#define EP93XX_PWMx_ENABLE 0x08 |
|
#define EP93XX_PWMx_INVERT 0x0c |
|
|
|
struct ep93xx_pwm { |
|
void __iomem *base; |
|
struct clk *clk; |
|
struct pwm_chip chip; |
|
}; |
|
|
|
static inline struct ep93xx_pwm *to_ep93xx_pwm(struct pwm_chip *chip) |
|
{ |
|
return container_of(chip, struct ep93xx_pwm, chip); |
|
} |
|
|
|
static int ep93xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) |
|
{ |
|
struct platform_device *pdev = to_platform_device(chip->dev); |
|
|
|
return ep93xx_pwm_acquire_gpio(pdev); |
|
} |
|
|
|
static void ep93xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) |
|
{ |
|
struct platform_device *pdev = to_platform_device(chip->dev); |
|
|
|
ep93xx_pwm_release_gpio(pdev); |
|
} |
|
|
|
static int ep93xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, |
|
int duty_ns, int period_ns) |
|
{ |
|
struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip); |
|
void __iomem *base = ep93xx_pwm->base; |
|
unsigned long long c; |
|
unsigned long period_cycles; |
|
unsigned long duty_cycles; |
|
unsigned long term; |
|
int ret = 0; |
|
|
|
/* |
|
* The clock needs to be enabled to access the PWM registers. |
|
* Configuration can be changed at any time. |
|
*/ |
|
if (!pwm_is_enabled(pwm)) { |
|
ret = clk_enable(ep93xx_pwm->clk); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
c = clk_get_rate(ep93xx_pwm->clk); |
|
c *= period_ns; |
|
do_div(c, 1000000000); |
|
period_cycles = c; |
|
|
|
c = period_cycles; |
|
c *= duty_ns; |
|
do_div(c, period_ns); |
|
duty_cycles = c; |
|
|
|
if (period_cycles < 0x10000 && duty_cycles < 0x10000) { |
|
term = readw(base + EP93XX_PWMx_TERM_COUNT); |
|
|
|
/* Order is important if PWM is running */ |
|
if (period_cycles > term) { |
|
writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT); |
|
writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE); |
|
} else { |
|
writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE); |
|
writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT); |
|
} |
|
} else { |
|
ret = -EINVAL; |
|
} |
|
|
|
if (!pwm_is_enabled(pwm)) |
|
clk_disable(ep93xx_pwm->clk); |
|
|
|
return ret; |
|
} |
|
|
|
static int ep93xx_pwm_polarity(struct pwm_chip *chip, struct pwm_device *pwm, |
|
enum pwm_polarity polarity) |
|
{ |
|
struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip); |
|
int ret; |
|
|
|
/* |
|
* The clock needs to be enabled to access the PWM registers. |
|
* Polarity can only be changed when the PWM is disabled. |
|
*/ |
|
ret = clk_enable(ep93xx_pwm->clk); |
|
if (ret) |
|
return ret; |
|
|
|
if (polarity == PWM_POLARITY_INVERSED) |
|
writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_INVERT); |
|
else |
|
writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_INVERT); |
|
|
|
clk_disable(ep93xx_pwm->clk); |
|
|
|
return 0; |
|
} |
|
|
|
static int ep93xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) |
|
{ |
|
struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip); |
|
int ret; |
|
|
|
ret = clk_enable(ep93xx_pwm->clk); |
|
if (ret) |
|
return ret; |
|
|
|
writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_ENABLE); |
|
|
|
return 0; |
|
} |
|
|
|
static void ep93xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) |
|
{ |
|
struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip); |
|
|
|
writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_ENABLE); |
|
clk_disable(ep93xx_pwm->clk); |
|
} |
|
|
|
static const struct pwm_ops ep93xx_pwm_ops = { |
|
.request = ep93xx_pwm_request, |
|
.free = ep93xx_pwm_free, |
|
.config = ep93xx_pwm_config, |
|
.set_polarity = ep93xx_pwm_polarity, |
|
.enable = ep93xx_pwm_enable, |
|
.disable = ep93xx_pwm_disable, |
|
.owner = THIS_MODULE, |
|
}; |
|
|
|
static int ep93xx_pwm_probe(struct platform_device *pdev) |
|
{ |
|
struct ep93xx_pwm *ep93xx_pwm; |
|
int ret; |
|
|
|
ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL); |
|
if (!ep93xx_pwm) |
|
return -ENOMEM; |
|
|
|
ep93xx_pwm->base = devm_platform_ioremap_resource(pdev, 0); |
|
if (IS_ERR(ep93xx_pwm->base)) |
|
return PTR_ERR(ep93xx_pwm->base); |
|
|
|
ep93xx_pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk"); |
|
if (IS_ERR(ep93xx_pwm->clk)) |
|
return PTR_ERR(ep93xx_pwm->clk); |
|
|
|
ep93xx_pwm->chip.dev = &pdev->dev; |
|
ep93xx_pwm->chip.ops = &ep93xx_pwm_ops; |
|
ep93xx_pwm->chip.base = -1; |
|
ep93xx_pwm->chip.npwm = 1; |
|
|
|
ret = pwmchip_add(&ep93xx_pwm->chip); |
|
if (ret < 0) |
|
return ret; |
|
|
|
platform_set_drvdata(pdev, ep93xx_pwm); |
|
return 0; |
|
} |
|
|
|
static int ep93xx_pwm_remove(struct platform_device *pdev) |
|
{ |
|
struct ep93xx_pwm *ep93xx_pwm = platform_get_drvdata(pdev); |
|
|
|
return pwmchip_remove(&ep93xx_pwm->chip); |
|
} |
|
|
|
static struct platform_driver ep93xx_pwm_driver = { |
|
.driver = { |
|
.name = "ep93xx-pwm", |
|
}, |
|
.probe = ep93xx_pwm_probe, |
|
.remove = ep93xx_pwm_remove, |
|
}; |
|
module_platform_driver(ep93xx_pwm_driver); |
|
|
|
MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver"); |
|
MODULE_AUTHOR("Matthieu Crapet <[email protected]>"); |
|
MODULE_AUTHOR("H Hartley Sweeten <[email protected]>"); |
|
MODULE_ALIAS("platform:ep93xx-pwm"); |
|
MODULE_LICENSE("GPL");
|
|
|