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ARM i.MX: Move i.MX pwm driver to pwm framework
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Move the driver to drivers/pwm/ and convert it to use the framework.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
[eric@eukrea.com: set chip.dev to prevent probe failure]
[eric@eukrea.com: fix pwmchip_add return code test]
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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Sascha Hauer authored and Thierry Reding committed Jul 2, 2012
1 parent 17b2b47 commit 2969324
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Showing 5 changed files with 82 additions and 118 deletions.
6 changes: 0 additions & 6 deletions arch/arm/plat-mxc/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -47,12 +47,6 @@ config MXC_TZIC
config MXC_AVIC
bool

config MXC_PWM
tristate "Enable PWM driver"
select HAVE_PWM
help
Enable support for the i.MX PWM controller(s).

config MXC_DEBUG_BOARD
bool "Enable MXC debug board(for 3-stack)"
help
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1 change: 0 additions & 1 deletion arch/arm/plat-mxc/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,6 @@ obj-$(CONFIG_MXC_AVIC) += avic.o
obj-$(CONFIG_IMX_HAVE_IOMUX_V1) += iomux-v1.o
obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o
obj-$(CONFIG_IRAM_ALLOC) += iram_alloc.o
obj-$(CONFIG_MXC_PWM) += pwm.o
obj-$(CONFIG_MXC_ULPI) += ulpi.o
obj-$(CONFIG_MXC_USE_EPIT) += epit.o
obj-$(CONFIG_MXC_DEBUG_BOARD) += 3ds_debugboard.o
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9 changes: 9 additions & 0 deletions drivers/pwm/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -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_IMX
tristate "i.MX pwm support"
depends on ARCH_MXC
help
Generic PWM framework driver for i.MX.

To compile this driver as a module, choose M here: the module
will be called pwm-imx.

config PWM_PXA
tristate "PXA PWM support"
depends on ARCH_PXA
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1 change: 1 addition & 0 deletions drivers/pwm/Makefile
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Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
obj-$(CONFIG_PWM) += core.o
obj-$(CONFIG_PWM_BFIN) += pwm-bfin.o
obj-$(CONFIG_PWM_IMX) += pwm-imx.o
obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
obj-$(CONFIG_PWM_TEGRA) += pwm-tegra.o
183 changes: 72 additions & 111 deletions arch/arm/plat-mxc/pwm.c → drivers/pwm/pwm-imx.c
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Original file line number Diff line number Diff line change
Expand Up @@ -39,33 +39,28 @@
#define MX3_PWMCR_CLKSRC_IPG (1 << 16)
#define MX3_PWMCR_EN (1 << 0)



struct pwm_device {
struct list_head node;
struct platform_device *pdev;

const char *label;
struct imx_chip {
struct clk *clk;

int clk_enabled;
void __iomem *mmio_base;

unsigned int use_count;
unsigned int pwm_id;
struct pwm_chip chip;
};

int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
#define to_imx_chip(chip) container_of(chip, struct imx_chip, chip)

static int imx_pwm_config(struct pwm_chip *chip,
struct pwm_device *pwm, int duty_ns, int period_ns)
{
if (pwm == NULL || period_ns == 0 || duty_ns > period_ns)
return -EINVAL;
struct imx_chip *imx = to_imx_chip(chip);

if (!(cpu_is_mx1() || cpu_is_mx21())) {
unsigned long long c;
unsigned long period_cycles, duty_cycles, prescale;
u32 cr;

c = clk_get_rate(pwm->clk);
c = clk_get_rate(imx->clk);
c = c * period_ns;
do_div(c, 1000000000);
period_cycles = c;
Expand All @@ -86,8 +81,8 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
else
period_cycles = 0;

writel(duty_cycles, pwm->mmio_base + MX3_PWMSAR);
writel(period_cycles, pwm->mmio_base + MX3_PWMPR);
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 |
Expand All @@ -98,7 +93,7 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
else
cr |= MX3_PWMCR_CLKSRC_IPG_HIGH;

writel(cr, pwm->mmio_base + MX3_PWMCR);
writel(cr, imx->mmio_base + MX3_PWMCR);
} else if (cpu_is_mx1() || cpu_is_mx21()) {
/* The PWM subsystem allows for exact frequencies. However,
* I cannot connect a scope on my device to the PWM line and
Expand All @@ -116,110 +111,73 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
* both the prescaler (/1 .. /128) and then by CLKSEL
* (/2 .. /16).
*/
u32 max = readl(pwm->mmio_base + MX1_PWMP);
u32 max = readl(imx->mmio_base + MX1_PWMP);
u32 p = max * duty_ns / period_ns;
writel(max - p, pwm->mmio_base + MX1_PWMS);
writel(max - p, imx->mmio_base + MX1_PWMS);
} else {
BUG();
}

return 0;
}
EXPORT_SYMBOL(pwm_config);

int pwm_enable(struct pwm_device *pwm)
static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct imx_chip *imx = to_imx_chip(chip);
int rc = 0;

if (!pwm->clk_enabled) {
rc = clk_prepare_enable(pwm->clk);
if (!imx->clk_enabled) {
rc = clk_prepare_enable(imx->clk);
if (!rc)
pwm->clk_enabled = 1;
imx->clk_enabled = 1;
}
return rc;
}
EXPORT_SYMBOL(pwm_enable);

void pwm_disable(struct pwm_device *pwm)
{
writel(0, pwm->mmio_base + MX3_PWMCR);

if (pwm->clk_enabled) {
clk_disable_unprepare(pwm->clk);
pwm->clk_enabled = 0;
}
}
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)
static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct pwm_device *pwm;
int found = 0;
struct imx_chip *imx = to_imx_chip(chip);

mutex_lock(&pwm_lock);
writel(0, imx->mmio_base + MX3_PWMCR);

list_for_each_entry(pwm, &pwm_list, node) {
if (pwm->pwm_id == pwm_id) {
found = 1;
break;
}
if (imx->clk_enabled) {
clk_disable_unprepare(imx->clk);
imx->clk_enabled = 0;
}

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 struct pwm_ops imx_pwm_ops = {
.enable = imx_pwm_enable,
.disable = imx_pwm_disable,
.config = imx_pwm_config,
.owner = THIS_MODULE,
};

static int __devinit mxc_pwm_probe(struct platform_device *pdev)
static int __devinit imx_pwm_probe(struct platform_device *pdev)
{
struct pwm_device *pwm;
struct imx_chip *imx;
struct resource *r;
int ret = 0;

pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
if (pwm == NULL) {
imx = kzalloc(sizeof(*imx), GFP_KERNEL);
if (imx == NULL) {
dev_err(&pdev->dev, "failed to allocate memory\n");
return -ENOMEM;
}

pwm->clk = clk_get(&pdev->dev, "pwm");
imx->clk = clk_get(&pdev->dev, "pwm");

if (IS_ERR(pwm->clk)) {
ret = PTR_ERR(pwm->clk);
if (IS_ERR(imx->clk)) {
ret = PTR_ERR(imx->clk);
goto err_free;
}

pwm->clk_enabled = 0;
imx->chip.ops = &imx_pwm_ops;
imx->chip.dev = &pdev->dev;
imx->chip.base = -1;
imx->chip.npwm = 1;

pwm->use_count = 0;
pwm->pwm_id = pdev->id;
pwm->pdev = pdev;
imx->clk_enabled = 0;

r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (r == NULL) {
Expand All @@ -235,72 +193,75 @@ static int __devinit mxc_pwm_probe(struct platform_device *pdev)
goto err_free_clk;
}

pwm->mmio_base = ioremap(r->start, resource_size(r));
if (pwm->mmio_base == NULL) {
imx->mmio_base = ioremap(r->start, resource_size(r));
if (imx->mmio_base == NULL) {
dev_err(&pdev->dev, "failed to ioremap() registers\n");
ret = -ENODEV;
goto err_free_mem;
}

mutex_lock(&pwm_lock);
list_add_tail(&pwm->node, &pwm_list);
mutex_unlock(&pwm_lock);
ret = pwmchip_add(&imx->chip);
if (ret < 0)
goto err_iounmap;

platform_set_drvdata(pdev, pwm);
platform_set_drvdata(pdev, imx);
return 0;

err_iounmap:
iounmap(imx->mmio_base);
err_free_mem:
release_mem_region(r->start, resource_size(r));
err_free_clk:
clk_put(pwm->clk);
clk_put(imx->clk);
err_free:
kfree(pwm);
kfree(imx);
return ret;
}

static int __devexit mxc_pwm_remove(struct platform_device *pdev)
static int __devexit imx_pwm_remove(struct platform_device *pdev)
{
struct pwm_device *pwm;
struct imx_chip *imx;
struct resource *r;
int ret;

pwm = platform_get_drvdata(pdev);
if (pwm == NULL)
imx = platform_get_drvdata(pdev);
if (imx == NULL)
return -ENODEV;

mutex_lock(&pwm_lock);
list_del(&pwm->node);
mutex_unlock(&pwm_lock);
ret = pwmchip_remove(&imx->chip);
if (ret)
return ret;

iounmap(pwm->mmio_base);
iounmap(imx->mmio_base);

r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(r->start, resource_size(r));

clk_put(pwm->clk);
clk_put(imx->clk);

kfree(pwm);
kfree(imx);
return 0;
}

static struct platform_driver mxc_pwm_driver = {
static struct platform_driver imx_pwm_driver = {
.driver = {
.name = "mxc_pwm",
},
.probe = mxc_pwm_probe,
.remove = __devexit_p(mxc_pwm_remove),
.probe = imx_pwm_probe,
.remove = __devexit_p(imx_pwm_remove),
};

static int __init mxc_pwm_init(void)
static int __init imx_pwm_init(void)
{
return platform_driver_register(&mxc_pwm_driver);
return platform_driver_register(&imx_pwm_driver);
}
arch_initcall(mxc_pwm_init);
arch_initcall(imx_pwm_init);

static void __exit mxc_pwm_exit(void)
static void __exit imx_pwm_exit(void)
{
platform_driver_unregister(&mxc_pwm_driver);
platform_driver_unregister(&imx_pwm_driver);
}
module_exit(mxc_pwm_exit);
module_exit(imx_pwm_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");

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