pwm: Add support for Broadcom iProc PWM controller
Add support for the PWM controller present in Broadcom's iProc family of SoCs. It has been tested on the Northstar+ bcm958625HR board. Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com> [thierry.reding@gmail.com: bunch of coding style fixes, cleanups] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Yendapally Reddy Dhananjaya Reddy
Thierry Reding
Родитель
f734f6ddbc
Коммит
daa5abc41c
|
|
@ -74,6 +74,16 @@ config PWM_ATMEL_TCB
|
|||
To compile this driver as a module, choose M here: the module
|
||||
will be called pwm-atmel-tcb.
|
||||
|
||||
config PWM_BCM_IPROC
|
||||
tristate "iProc PWM support"
|
||||
depends on ARCH_BCM_IPROC
|
||||
help
|
||||
Generic PWM framework driver for Broadcom iProc PWM block. This
|
||||
block is used in Broadcom iProc SoC's.
|
||||
|
||||
To compile this driver as a module, choose M here: the module
|
||||
will be called pwm-bcm-iproc.
|
||||
|
||||
config PWM_BCM_KONA
|
||||
tristate "Kona PWM support"
|
||||
depends on ARCH_BCM_MOBILE
|
||||
|
|
|
|||
|
|
@ -4,6 +4,7 @@ obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o
|
|||
obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o
|
||||
obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM) += pwm-atmel-hlcdc.o
|
||||
obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o
|
||||
obj-$(CONFIG_PWM_BCM_IPROC) += pwm-bcm-iproc.o
|
||||
obj-$(CONFIG_PWM_BCM_KONA) += pwm-bcm-kona.o
|
||||
obj-$(CONFIG_PWM_BCM2835) += pwm-bcm2835.o
|
||||
obj-$(CONFIG_PWM_BERLIN) += pwm-berlin.o
|
||||
|
|
|
|||
|
|
@ -0,0 +1,277 @@
|
|||
/*
|
||||
* Copyright (C) 2016 Broadcom
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License as
|
||||
* published by the Free Software Foundation version 2.
|
||||
*
|
||||
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
|
||||
* kind, whether express or implied; without even the implied warranty
|
||||
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*/
|
||||
|
||||
#include <linux/clk.h>
|
||||
#include <linux/delay.h>
|
||||
#include <linux/err.h>
|
||||
#include <linux/io.h>
|
||||
#include <linux/math64.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/of.h>
|
||||
#include <linux/platform_device.h>
|
||||
#include <linux/pwm.h>
|
||||
|
||||
#define IPROC_PWM_CTRL_OFFSET 0x00
|
||||
#define IPROC_PWM_CTRL_TYPE_SHIFT(ch) (15 + (ch))
|
||||
#define IPROC_PWM_CTRL_POLARITY_SHIFT(ch) (8 + (ch))
|
||||
#define IPROC_PWM_CTRL_EN_SHIFT(ch) (ch)
|
||||
|
||||
#define IPROC_PWM_PERIOD_OFFSET(ch) (0x04 + ((ch) << 3))
|
||||
#define IPROC_PWM_PERIOD_MIN 0x02
|
||||
#define IPROC_PWM_PERIOD_MAX 0xffff
|
||||
|
||||
#define IPROC_PWM_DUTY_CYCLE_OFFSET(ch) (0x08 + ((ch) << 3))
|
||||
#define IPROC_PWM_DUTY_CYCLE_MIN 0x00
|
||||
#define IPROC_PWM_DUTY_CYCLE_MAX 0xffff
|
||||
|
||||
#define IPROC_PWM_PRESCALE_OFFSET 0x24
|
||||
#define IPROC_PWM_PRESCALE_BITS 0x06
|
||||
#define IPROC_PWM_PRESCALE_SHIFT(ch) ((3 - (ch)) * \
|
||||
IPROC_PWM_PRESCALE_BITS)
|
||||
#define IPROC_PWM_PRESCALE_MASK(ch) (IPROC_PWM_PRESCALE_MAX << \
|
||||
IPROC_PWM_PRESCALE_SHIFT(ch))
|
||||
#define IPROC_PWM_PRESCALE_MIN 0x00
|
||||
#define IPROC_PWM_PRESCALE_MAX 0x3f
|
||||
|
||||
struct iproc_pwmc {
|
||||
struct pwm_chip chip;
|
||||
void __iomem *base;
|
||||
struct clk *clk;
|
||||
};
|
||||
|
||||
static inline struct iproc_pwmc *to_iproc_pwmc(struct pwm_chip *chip)
|
||||
{
|
||||
return container_of(chip, struct iproc_pwmc, chip);
|
||||
}
|
||||
|
||||
static void iproc_pwmc_enable(struct iproc_pwmc *ip, unsigned int channel)
|
||||
{
|
||||
u32 value;
|
||||
|
||||
value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
value |= 1 << IPROC_PWM_CTRL_EN_SHIFT(channel);
|
||||
writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
|
||||
/* must be a 400 ns delay between clearing and setting enable bit */
|
||||
ndelay(400);
|
||||
}
|
||||
|
||||
static void iproc_pwmc_disable(struct iproc_pwmc *ip, unsigned int channel)
|
||||
{
|
||||
u32 value;
|
||||
|
||||
value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
value &= ~(1 << IPROC_PWM_CTRL_EN_SHIFT(channel));
|
||||
writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
|
||||
/* must be a 400 ns delay between clearing and setting enable bit */
|
||||
ndelay(400);
|
||||
}
|
||||
|
||||
static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
|
||||
struct pwm_state *state)
|
||||
{
|
||||
struct iproc_pwmc *ip = to_iproc_pwmc(chip);
|
||||
u64 tmp, multi, rate;
|
||||
u32 value, prescale;
|
||||
|
||||
rate = clk_get_rate(ip->clk);
|
||||
|
||||
value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
|
||||
if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm)))
|
||||
state->enabled = true;
|
||||
else
|
||||
state->enabled = false;
|
||||
|
||||
if (value & BIT(IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm)))
|
||||
state->polarity = PWM_POLARITY_NORMAL;
|
||||
else
|
||||
state->polarity = PWM_POLARITY_INVERSED;
|
||||
|
||||
value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
|
||||
prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
|
||||
prescale &= IPROC_PWM_PRESCALE_MAX;
|
||||
|
||||
multi = NSEC_PER_SEC * (prescale + 1);
|
||||
|
||||
value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
|
||||
tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
|
||||
state->period = div64_u64(tmp, rate);
|
||||
|
||||
value = readl(ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
|
||||
tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
|
||||
state->duty_cycle = div64_u64(tmp, rate);
|
||||
}
|
||||
|
||||
static int iproc_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm,
|
||||
struct pwm_state *state)
|
||||
{
|
||||
unsigned long prescale = IPROC_PWM_PRESCALE_MIN;
|
||||
struct iproc_pwmc *ip = to_iproc_pwmc(chip);
|
||||
u32 value, period, duty;
|
||||
u64 rate;
|
||||
|
||||
rate = clk_get_rate(ip->clk);
|
||||
|
||||
/*
|
||||
* Find period count, duty count and prescale to suit duty_cycle and
|
||||
* period. This is done according to formulas described below:
|
||||
*
|
||||
* period_ns = 10^9 * (PRESCALE + 1) * PC / PWM_CLK_RATE
|
||||
* duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
|
||||
*
|
||||
* PC = (PWM_CLK_RATE * period_ns) / (10^9 * (PRESCALE + 1))
|
||||
* DC = (PWM_CLK_RATE * duty_ns) / (10^9 * (PRESCALE + 1))
|
||||
*/
|
||||
while (1) {
|
||||
u64 value, div;
|
||||
|
||||
div = NSEC_PER_SEC * (prescale + 1);
|
||||
value = rate * state->period;
|
||||
period = div64_u64(value, div);
|
||||
value = rate * state->duty_cycle;
|
||||
duty = div64_u64(value, div);
|
||||
|
||||
if (period < IPROC_PWM_PERIOD_MIN ||
|
||||
duty < IPROC_PWM_DUTY_CYCLE_MIN)
|
||||
return -EINVAL;
|
||||
|
||||
if (period <= IPROC_PWM_PERIOD_MAX &&
|
||||
duty <= IPROC_PWM_DUTY_CYCLE_MAX)
|
||||
break;
|
||||
|
||||
/* Otherwise, increase prescale and recalculate counts */
|
||||
if (++prescale > IPROC_PWM_PRESCALE_MAX)
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
iproc_pwmc_disable(ip, pwm->hwpwm);
|
||||
|
||||
/* Set prescale */
|
||||
value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
|
||||
value &= ~IPROC_PWM_PRESCALE_MASK(pwm->hwpwm);
|
||||
value |= prescale << IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
|
||||
writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET);
|
||||
|
||||
/* set period and duty cycle */
|
||||
writel(period, ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
|
||||
writel(duty, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
|
||||
|
||||
/* set polarity */
|
||||
value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
|
||||
if (state->polarity == PWM_POLARITY_NORMAL)
|
||||
value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm);
|
||||
else
|
||||
value &= ~(1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm));
|
||||
|
||||
writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
|
||||
if (state->enabled)
|
||||
iproc_pwmc_enable(ip, pwm->hwpwm);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static const struct pwm_ops iproc_pwm_ops = {
|
||||
.apply = iproc_pwmc_apply,
|
||||
.get_state = iproc_pwmc_get_state,
|
||||
};
|
||||
|
||||
static int iproc_pwmc_probe(struct platform_device *pdev)
|
||||
{
|
||||
struct iproc_pwmc *ip;
|
||||
struct resource *res;
|
||||
unsigned int i;
|
||||
u32 value;
|
||||
int ret;
|
||||
|
||||
ip = devm_kzalloc(&pdev->dev, sizeof(*ip), GFP_KERNEL);
|
||||
if (!ip)
|
||||
return -ENOMEM;
|
||||
|
||||
platform_set_drvdata(pdev, ip);
|
||||
|
||||
ip->chip.dev = &pdev->dev;
|
||||
ip->chip.ops = &iproc_pwm_ops;
|
||||
ip->chip.base = -1;
|
||||
ip->chip.npwm = 4;
|
||||
ip->chip.of_xlate = of_pwm_xlate_with_flags;
|
||||
ip->chip.of_pwm_n_cells = 3;
|
||||
|
||||
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
||||
ip->base = devm_ioremap_resource(&pdev->dev, res);
|
||||
if (IS_ERR(ip->base))
|
||||
return PTR_ERR(ip->base);
|
||||
|
||||
ip->clk = devm_clk_get(&pdev->dev, NULL);
|
||||
if (IS_ERR(ip->clk)) {
|
||||
dev_err(&pdev->dev, "failed to get clock: %ld\n",
|
||||
PTR_ERR(ip->clk));
|
||||
return PTR_ERR(ip->clk);
|
||||
}
|
||||
|
||||
ret = clk_prepare_enable(ip->clk);
|
||||
if (ret < 0) {
|
||||
dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* Set full drive and normal polarity for all channels */
|
||||
value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
|
||||
for (i = 0; i < ip->chip.npwm; i++) {
|
||||
value &= ~(1 << IPROC_PWM_CTRL_TYPE_SHIFT(i));
|
||||
value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(i);
|
||||
}
|
||||
|
||||
writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
|
||||
|
||||
ret = pwmchip_add(&ip->chip);
|
||||
if (ret < 0) {
|
||||
dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
|
||||
clk_disable_unprepare(ip->clk);
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int iproc_pwmc_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct iproc_pwmc *ip = platform_get_drvdata(pdev);
|
||||
|
||||
clk_disable_unprepare(ip->clk);
|
||||
|
||||
return pwmchip_remove(&ip->chip);
|
||||
}
|
||||
|
||||
static const struct of_device_id bcm_iproc_pwmc_dt[] = {
|
||||
{ .compatible = "brcm,iproc-pwm" },
|
||||
{ },
|
||||
};
|
||||
MODULE_DEVICE_TABLE(of, bcm_iproc_pwmc_dt);
|
||||
|
||||
static struct platform_driver iproc_pwmc_driver = {
|
||||
.driver = {
|
||||
.name = "bcm-iproc-pwm",
|
||||
.of_match_table = bcm_iproc_pwmc_dt,
|
||||
},
|
||||
.probe = iproc_pwmc_probe,
|
||||
.remove = iproc_pwmc_remove,
|
||||
};
|
||||
module_platform_driver(iproc_pwmc_driver);
|
||||
|
||||
MODULE_AUTHOR("Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>");
|
||||
MODULE_DESCRIPTION("Broadcom iProc PWM driver");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
Загрузка…
Ссылка в новой задаче