From c860d701cc5f77b74c481dcbd25b2d8b31c622fc Mon Sep 17 00:00:00 2001
From: Robert Jarzmik <rjarzmik@free.fr>
Date: Tue, 10 Jun 2008 23:02:31 +0100
Subject: [PATCH] [ARM] 5087/1: Get the PWM layer to handle clock
enable/disable properly.
Allow pwm_enable()/pwm_disable() to be called as many times
as the driver wants (and not even count them).
The PWM model is different from things like the clock API
where we need enable counting, because PWMs have one
exclusive user per PWM whereas the clock API can have
multiple users of the same clock.
Acked-by: eric miao <eric.miao@marvell.com>
Signed-off-by: Robert Jarzmik <rjarzmik@free.fr>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/mach-pxa/pwm.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-pxa/pwm.c b/arch/arm/mach-pxa/pwm.c
index 92fef391d990..7c86dd1d108f 100644
--- a/arch/arm/mach-pxa/pwm.c
+++ b/arch/arm/mach-pxa/pwm.c
@@ -36,6 +36,7 @@ struct pwm_device {
const char *label;
struct clk *clk;
+ int clk_enabled;
void __iomem *mmio_base;
unsigned int use_count;
@@ -87,13 +88,23 @@ EXPORT_SYMBOL(pwm_config);
int pwm_enable(struct pwm_device *pwm)
{
- return clk_enable(pwm->clk);
+ int rc = 0;
+
+ if (!pwm->clk_enabled) {
+ rc = clk_enable(pwm->clk);
+ if (!rc)
+ pwm->clk_enabled = 1;
+ }
+ return rc;
}
EXPORT_SYMBOL(pwm_enable);
void pwm_disable(struct pwm_device *pwm)
{
- clk_disable(pwm->clk);
+ if (pwm->clk_enabled) {
+ clk_disable(pwm->clk);
+ pwm->clk_enabled = 0;
+ }
}
EXPORT_SYMBOL(pwm_disable);
@@ -161,6 +172,7 @@ static struct pwm_device *pwm_probe(struct platform_device *pdev,
ret = PTR_ERR(pwm->clk);
goto err_free;
}
+ pwm->clk_enabled = 0;
pwm->use_count = 0;
pwm->pwm_id = pwm_id;
--
GitLab