Since 2011 barebox' of_device_id struct uses unsigned long type for data field: struct of_device_id { char *compatible; unsigned long data; }; Almost always struct of_device_id.data field are used as pointer and need 'unsigned long' casting. E.g. see 'git grep -A 4 of_device_id drivers/' output: drivers/ata/sata-imx.c:static __maybe_unused struct of_device_id imx_sata_dt_ids[] = { drivers/ata/sata-imx.c- { drivers/ata/sata-imx.c- .compatible = "fsl,imx6q-ahci", drivers/ata/sata-imx.c- .data = (unsigned long)&data_imx6, drivers/ata/sata-imx.c- }, { Here is of_device_id struct in linux kernel v4.0: struct of_device_id { char name[32]; char type[32]; char compatible[128]; const void *data; }; Changing of_device_id.data type to 'const void *data' will increase barebox' linux kernel compatibility and decrease number of 'unsigned long' casts. Part of the patch was done using the 'coccinelle' tool with the following semantic patch: @rule1@ identifier dev; identifier type; identifier func; @@ func(...) { <... - dev_get_drvdata(dev, (unsigned long *)&type) + dev_get_drvdata(dev, (const void **)&type) ...> } @rule2@ identifier dev; identifier type; identifier func; identifier data; @@ func(...) { <... - dev_get_drvdata(dev, (unsigned long *)&type->data) + dev_get_drvdata(dev, (const void **)&type->data) ...> } Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
262 lines
6.3 KiB
C
262 lines
6.3 KiB
C
/*
|
|
* simple driver for PWM (Pulse Width Modulator) controller
|
|
*
|
|
* 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.
|
|
*
|
|
* Derived from pxa PWM driver by eric miao <eric.miao@marvell.com>
|
|
*/
|
|
|
|
#include <common.h>
|
|
#include <init.h>
|
|
#include <errno.h>
|
|
#include <io.h>
|
|
#include <pwm.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/err.h>
|
|
#include <asm-generic/div64.h>
|
|
|
|
/* i.MX1 and i.MX21 share the same PWM function block: */
|
|
|
|
#define MX1_PWMC 0x00 /* PWM Control Register */
|
|
#define MX1_PWMS 0x04 /* PWM Sample Register */
|
|
#define MX1_PWMP 0x08 /* PWM Period Register */
|
|
|
|
#define MX1_PWMC_EN (1 << 4)
|
|
|
|
/* i.MX27, i.MX31, i.MX35 share the same PWM function block: */
|
|
|
|
#define MX3_PWMCR 0x00 /* PWM Control Register */
|
|
#define MX3_PWMSAR 0x0C /* PWM Sample Register */
|
|
#define MX3_PWMPR 0x10 /* PWM Period Register */
|
|
#define MX3_PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4)
|
|
#define MX3_PWMCR_DOZEEN (1 << 24)
|
|
#define MX3_PWMCR_WAITEN (1 << 23)
|
|
#define MX3_PWMCR_DBGEN (1 << 22)
|
|
#define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16)
|
|
#define MX3_PWMCR_CLKSRC_IPG (1 << 16)
|
|
#define MX3_PWMCR_EN (1 << 0)
|
|
|
|
struct imx_chip {
|
|
struct clk *clk_per;
|
|
|
|
void __iomem *mmio_base;
|
|
|
|
struct pwm_chip chip;
|
|
|
|
int (*config)(struct pwm_chip *chip,
|
|
int duty_ns, int period_ns);
|
|
void (*set_enable)(struct pwm_chip *chip, bool enable);
|
|
};
|
|
|
|
#define to_imx_chip(chip) container_of(chip, struct imx_chip, chip)
|
|
|
|
static int imx_pwm_config_v1(struct pwm_chip *chip,
|
|
int duty_ns, int period_ns)
|
|
{
|
|
struct imx_chip *imx = to_imx_chip(chip);
|
|
|
|
/*
|
|
* The PWM subsystem allows for exact frequencies. However,
|
|
* I cannot connect a scope on my device to the PWM line and
|
|
* thus cannot provide the program the PWM controller
|
|
* exactly. Instead, I'm relying on the fact that the
|
|
* Bootloader (u-boot or WinCE+haret) has programmed the PWM
|
|
* function group already. So I'll just modify the PWM sample
|
|
* register to follow the ratio of duty_ns vs. period_ns
|
|
* accordingly.
|
|
*
|
|
* This is good enough for programming the brightness of
|
|
* the LCD backlight.
|
|
*
|
|
* The real implementation would divide PERCLK[0] first by
|
|
* both the prescaler (/1 .. /128) and then by CLKSEL
|
|
* (/2 .. /16).
|
|
*/
|
|
u32 max = readl(imx->mmio_base + MX1_PWMP);
|
|
u32 p = max * duty_ns / period_ns;
|
|
writel(max - p, imx->mmio_base + MX1_PWMS);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void imx_pwm_set_enable_v1(struct pwm_chip *chip, bool enable)
|
|
{
|
|
struct imx_chip *imx = to_imx_chip(chip);
|
|
u32 val;
|
|
|
|
val = readl(imx->mmio_base + MX1_PWMC);
|
|
|
|
if (enable)
|
|
val |= MX1_PWMC_EN;
|
|
else
|
|
val &= ~MX1_PWMC_EN;
|
|
|
|
writel(val, imx->mmio_base + MX1_PWMC);
|
|
}
|
|
|
|
static int imx_pwm_config_v2(struct pwm_chip *chip,
|
|
int duty_ns, int period_ns)
|
|
{
|
|
struct imx_chip *imx = to_imx_chip(chip);
|
|
unsigned long long c;
|
|
unsigned long period_cycles, duty_cycles, prescale;
|
|
u32 cr;
|
|
|
|
c = clk_get_rate(imx->clk_per);
|
|
c = c * period_ns;
|
|
do_div(c, 1000000000);
|
|
period_cycles = c;
|
|
|
|
prescale = period_cycles / 0x10000 + 1;
|
|
|
|
period_cycles /= prescale;
|
|
c = (unsigned long long)period_cycles * duty_ns;
|
|
do_div(c, period_ns);
|
|
duty_cycles = c;
|
|
|
|
/*
|
|
* according to imx pwm RM, the real period value should be
|
|
* PERIOD value in PWMPR plus 2.
|
|
*/
|
|
if (period_cycles > 2)
|
|
period_cycles -= 2;
|
|
else
|
|
period_cycles = 0;
|
|
|
|
writel(duty_cycles, imx->mmio_base + MX3_PWMSAR);
|
|
writel(period_cycles, imx->mmio_base + MX3_PWMPR);
|
|
|
|
cr = MX3_PWMCR_PRESCALER(prescale) |
|
|
MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN |
|
|
MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH;
|
|
|
|
if (readl(imx->mmio_base + MX3_PWMCR) & MX3_PWMCR_EN)
|
|
cr |= MX3_PWMCR_EN;
|
|
|
|
writel(cr, imx->mmio_base + MX3_PWMCR);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable)
|
|
{
|
|
struct imx_chip *imx = to_imx_chip(chip);
|
|
u32 val;
|
|
|
|
val = readl(imx->mmio_base + MX3_PWMCR);
|
|
|
|
if (enable)
|
|
val |= MX3_PWMCR_EN;
|
|
else
|
|
val &= ~MX3_PWMCR_EN;
|
|
|
|
writel(val, imx->mmio_base + MX3_PWMCR);
|
|
}
|
|
|
|
static int imx_pwm_config(struct pwm_chip *chip,
|
|
int duty_ns, int period_ns)
|
|
{
|
|
struct imx_chip *imx = to_imx_chip(chip);
|
|
int ret;
|
|
|
|
ret = imx->config(chip, duty_ns, period_ns);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int imx_pwm_enable(struct pwm_chip *chip)
|
|
{
|
|
struct imx_chip *imx = to_imx_chip(chip);
|
|
|
|
imx->set_enable(chip, true);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void imx_pwm_disable(struct pwm_chip *chip)
|
|
{
|
|
struct imx_chip *imx = to_imx_chip(chip);
|
|
|
|
imx->set_enable(chip, false);
|
|
}
|
|
|
|
static struct pwm_ops imx_pwm_ops = {
|
|
.enable = imx_pwm_enable,
|
|
.disable = imx_pwm_disable,
|
|
.config = imx_pwm_config,
|
|
};
|
|
|
|
struct imx_pwm_data {
|
|
int (*config)(struct pwm_chip *chip,
|
|
int duty_ns, int period_ns);
|
|
void (*set_enable)(struct pwm_chip *chip, bool enable);
|
|
};
|
|
|
|
static struct imx_pwm_data imx_pwm_data_v1 = {
|
|
.config = imx_pwm_config_v1,
|
|
.set_enable = imx_pwm_set_enable_v1,
|
|
};
|
|
|
|
static struct imx_pwm_data imx_pwm_data_v2 = {
|
|
.config = imx_pwm_config_v2,
|
|
.set_enable = imx_pwm_set_enable_v2,
|
|
};
|
|
|
|
static struct of_device_id imx_pwm_dt_ids[] = {
|
|
{ .compatible = "fsl,imx1-pwm", .data = &imx_pwm_data_v1, },
|
|
{ .compatible = "fsl,imx27-pwm", .data = &imx_pwm_data_v2, },
|
|
{ /* sentinel */ }
|
|
};
|
|
|
|
static int imx_pwm_probe(struct device_d *dev)
|
|
{
|
|
const struct imx_pwm_data *data;
|
|
struct imx_chip *imx;
|
|
int ret = 0;
|
|
|
|
ret = dev_get_drvdata(dev, (const void **)&data);
|
|
if (ret)
|
|
return ret;
|
|
|
|
imx = xzalloc(sizeof(*imx));
|
|
|
|
imx->clk_per = clk_get(dev, "per");
|
|
if (IS_ERR(imx->clk_per))
|
|
return PTR_ERR(imx->clk_per);
|
|
|
|
imx->mmio_base = dev_request_mem_region(dev, 0);
|
|
if (IS_ERR(imx->mmio_base))
|
|
return PTR_ERR(imx->mmio_base);
|
|
|
|
imx->chip.ops = &imx_pwm_ops;
|
|
if (dev->device_node) {
|
|
imx->chip.devname = of_alias_get(dev->device_node);
|
|
if (!imx->chip.devname)
|
|
imx->chip.devname = asprintf("pwm_%p", imx->mmio_base);
|
|
} else {
|
|
imx->chip.devname = asprintf("pwm%d", dev->id);
|
|
}
|
|
|
|
imx->config = data->config;
|
|
imx->set_enable = data->set_enable;
|
|
|
|
ret = pwmchip_add(&imx->chip, dev);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct driver_d imx_pwm_driver = {
|
|
.name = "imx-pwm",
|
|
.of_compatible = imx_pwm_dt_ids,
|
|
.probe = imx_pwm_probe,
|
|
};
|
|
|
|
coredevice_platform_driver(imx_pwm_driver);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
|