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pwm: Move PXA PWM driver to PWM framework 

This commit moves the PXA PWM driver to the drivers/pwm subdirectory and
converts it to use the new PWM framework.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
This commit is contained in:
Thierry Reding 2012-01-02 21:22:38 +01:00
parent a4315e3c11
commit 17b2b4780f
4 changed files with 69 additions and 116 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm/plat-pxa/Makefile
View File

@ -8,5 +8,4 @@ obj-$(CONFIG_PXA3xx) += mfp.o
obj-$(CONFIG_PXA95x) += mfp.o
obj-$(CONFIG_ARCH_MMP) += mfp.o
obj-$(CONFIG_HAVE_PWM) += pwm.o
obj-$(CONFIG_PXA_SSP) += ssp.o

9
drivers/pwm/Kconfig
View File

@ -18,6 +18,15 @@ config PWM_BFIN
To compile this driver as a module, choose M here: the module
will be called pwm-bfin.
config PWM_PXA
tristate "PXA PWM support"
depends on ARCH_PXA
help
Generic PWM framework driver for PXA.
To compile this driver as a module, choose M here: the module
will be called pwm-pxa.
config PWM_TEGRA
tristate "NVIDIA Tegra PWM support"
depends on ARCH_TEGRA

1
drivers/pwm/Makefile
View File

@ -1,3 +1,4 @@
obj-$(CONFIG_PWM) += core.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o

174
arch/arm/plat-pxa/pwm.c → drivers/pwm/pwm-pxa.c
View File

@ -43,33 +43,39 @@ MODULE_DEVICE_TABLE(platform, pwm_id_table);
#define PWMCR_SD (1 << 6)
#define PWMDCR_FD (1 << 10)
struct pwm_device {
struct list_head node;
struct pwm_device *secondary;
struct platform_device *pdev;
struct pxa_pwm_chip {
struct pwm_chip chip;
struct device *dev;
const char *label;
struct clk *clk;
int clk_enabled;
void __iomem *mmio_base;
unsigned int use_count;
unsigned int pwm_id;
};
static inline struct pxa_pwm_chip *to_pxa_pwm_chip(struct pwm_chip *chip)
{
return container_of(chip, struct pxa_pwm_chip, chip);
}
/*
* period_ns = 10^9 * (PRESCALE + 1) * (PV + 1) / PWM_CLK_RATE
* duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
*/
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
unsigned long long c;
unsigned long period_cycles, prescale, pv, dc;
unsigned long offset;
int rc;
if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
if (period_ns == 0 || duty_ns > period_ns)
return -EINVAL;
c = clk_get_rate(pwm->clk);
offset = pwm->hwpwm ? 0x10 : 0;
c = clk_get_rate(pc->clk);
c = c * period_ns;
do_div(c, 1000000000);
period_cycles = c;
@ -90,98 +96,56 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
/* NOTE: the clock to PWM has to be enabled first
* before writing to the registers
*/
clk_enable(pwm->clk);
__raw_writel(prescale, pwm->mmio_base + PWMCR);
__raw_writel(dc, pwm->mmio_base + PWMDCR);
__raw_writel(pv, pwm->mmio_base + PWMPCR);
clk_disable(pwm->clk);
rc = clk_prepare_enable(pc->clk);
if (rc < 0)
return rc;
writel(prescale, pc->mmio_base + offset + PWMCR);
writel(dc, pc->mmio_base + offset + PWMDCR);
writel(pv, pc->mmio_base + offset + PWMPCR);
clk_disable_unprepare(pc->clk);
return 0;
}
EXPORT_SYMBOL(pwm_config);
int pwm_enable(struct pwm_device *pwm)
static int pxa_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
int rc = 0;
if (!pwm->clk_enabled) {
rc = clk_enable(pwm->clk);
if (!pc->clk_enabled) {
rc = clk_prepare_enable(pc->clk);
if (!rc)
pwm->clk_enabled = 1;
pc->clk_enabled++;
}
return rc;
}
EXPORT_SYMBOL(pwm_enable);
void pwm_disable(struct pwm_device *pwm)
static void pxa_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
if (pwm->clk_enabled) {
clk_disable(pwm->clk);
pwm->clk_enabled = 0;
struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
if (pc->clk_enabled) {
clk_disable_unprepare(pc->clk);
pc->clk_enabled--;
}
}
EXPORT_SYMBOL(pwm_disable);
static DEFINE_MUTEX(pwm_lock);
static LIST_HEAD(pwm_list);
struct pwm_device *pwm_request(int pwm_id, const char *label)
{
struct pwm_device *pwm;
int found = 0;
mutex_lock(&pwm_lock);
list_for_each_entry(pwm, &pwm_list, node) {
if (pwm->pwm_id == pwm_id) {
found = 1;
break;
}
}
if (found) {
if (pwm->use_count == 0) {
pwm->use_count++;
pwm->label = label;
} else
pwm = ERR_PTR(-EBUSY);
} else
pwm = ERR_PTR(-ENOENT);
mutex_unlock(&pwm_lock);
return pwm;
}
EXPORT_SYMBOL(pwm_request);
void pwm_free(struct pwm_device *pwm)
{
mutex_lock(&pwm_lock);
if (pwm->use_count) {
pwm->use_count--;
pwm->label = NULL;
} else
pr_warning("PWM device already freed\n");
mutex_unlock(&pwm_lock);
}
EXPORT_SYMBOL(pwm_free);
static inline void __add_pwm(struct pwm_device *pwm)
{
mutex_lock(&pwm_lock);
list_add_tail(&pwm->node, &pwm_list);
mutex_unlock(&pwm_lock);
}
static struct pwm_ops pxa_pwm_ops = {
.config = pxa_pwm_config,
.enable = pxa_pwm_enable,
.disable = pxa_pwm_disable,
.owner = THIS_MODULE,
};
static int __devinit pwm_probe(struct platform_device *pdev)
{
const struct platform_device_id *id = platform_get_device_id(pdev);
struct pwm_device *pwm, *secondary = NULL;
struct pxa_pwm_chip *pwm;
struct resource *r;
int ret = 0;
pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
pwm = kzalloc(sizeof(*pwm), GFP_KERNEL);
if (pwm == NULL) {
dev_err(&pdev->dev, "failed to allocate memory\n");
return -ENOMEM;
@ -194,9 +158,10 @@ static int __devinit pwm_probe(struct platform_device *pdev)
}
pwm->clk_enabled = 0;
pwm->use_count = 0;
pwm->pwm_id = PWM_ID_BASE(id->driver_data) + pdev->id;
pwm->pdev = pdev;
pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &pxa_pwm_ops;
pwm->chip.base = -1;
pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL) {
@ -219,25 +184,12 @@ static int __devinit pwm_probe(struct platform_device *pdev)
goto err_free_mem;
}
if (id->driver_data & HAS_SECONDARY_PWM) {
secondary = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
if (secondary == NULL) {
ret = -ENOMEM;
goto err_free_mem;
}
*secondary = *pwm;
pwm->secondary = secondary;
/* registers for the second PWM has offset of 0x10 */
secondary->mmio_base = pwm->mmio_base + 0x10;
secondary->pwm_id = pdev->id + 2;
ret = pwmchip_add(&pwm->chip);
if (ret < 0) {
dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
return ret;
}
__add_pwm(pwm);
if (secondary)
__add_pwm(secondary);
platform_set_drvdata(pdev, pwm);
return 0;
@ -252,30 +204,22 @@ err_free:
static int __devexit pwm_remove(struct platform_device *pdev)
{
struct pwm_device *pwm;
struct pxa_pwm_chip *chip;
struct resource *r;
pwm = platform_get_drvdata(pdev);
if (pwm == NULL)
chip = platform_get_drvdata(pdev);
if (chip == NULL)
return -ENODEV;
mutex_lock(&pwm_lock);
pwmchip_remove(&chip->chip);
if (pwm->secondary) {
list_del(&pwm->secondary->node);
kfree(pwm->secondary);
}
list_del(&pwm->node);
mutex_unlock(&pwm_lock);
iounmap(pwm->mmio_base);
iounmap(chip->mmio_base);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(r->start, resource_size(r));
clk_put(pwm->clk);
kfree(pwm);
clk_put(chip->clk);
kfree(chip);
return 0;
}