From: Thierry Reding <thierry.reding@avionic-design.de>
To: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Mike Turquette <mturquette@linaro.org>, linux-kernel@vger.kernel.org
Subject: [PATCH 1/6] unicore32: pwm: Properly remap memory-mapped registers
Date: Sun, 2 Sep 2012 12:21:08 +0200 [thread overview]
Message-ID: <1346581273-7041-2-git-send-email-thierry.reding@avionic-design.de> (raw)
In-Reply-To: <1346581273-7041-1-git-send-email-thierry.reding@avionic-design.de>
Instead of writing to the timer controller registers by dereferencing a
pointer to the memory location, properly remap the memory region with a
call to ioremap_nocache() and access the registers using writel().
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
---
arch/unicore32/kernel/pwm.c | 25 ++++++++++++++++++++++---
1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/arch/unicore32/kernel/pwm.c b/arch/unicore32/kernel/pwm.c
index 4615d51..410b786 100644
--- a/arch/unicore32/kernel/pwm.c
+++ b/arch/unicore32/kernel/pwm.c
@@ -23,10 +23,16 @@
#include <asm/div64.h>
#include <mach/hardware.h>
+#define PWCR 0x00
+#define DCCR 0x04
+#define PCR 0x08
+
struct pwm_device {
struct list_head node;
struct platform_device *pdev;
+ void __iomem *base;
+
const char *label;
struct clk *clk;
int clk_enabled;
@@ -69,9 +75,11 @@ int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
* before writing to the registers
*/
clk_enable(pwm->clk);
- OST_PWMPWCR = prescale;
- OST_PWMDCCR = pv - dc;
- OST_PWMPCR = pv;
+
+ writel(prescale, pwm->base + PWCR);
+ writel(pv - dc, pwm->base + DCCR);
+ writel(pv, pwm->base + PCR);
+
clk_disable(pwm->clk);
return 0;
@@ -190,10 +198,19 @@ static struct pwm_device *pwm_probe(struct platform_device *pdev,
goto err_free_clk;
}
+ pwm->base = ioremap_nocache(r->start, resource_size(r));
+ if (pwm->base == NULL) {
+ dev_err(&pdev->dev, "failed to remap memory resource\n");
+ ret = -EADDRNOTAVAIL;
+ goto err_release_mem;
+ }
+
__add_pwm(pwm);
platform_set_drvdata(pdev, pwm);
return pwm;
+err_release_mem:
+ release_mem_region(r->start, resource_size(r));
err_free_clk:
clk_put(pwm->clk);
err_free:
@@ -224,6 +241,8 @@ static int __devexit pwm_remove(struct platform_device *pdev)
list_del(&pwm->node);
mutex_unlock(&pwm_lock);
+ iounmap(pwm->base);
+
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(r->start, resource_size(r));
--
1.7.12
next prev parent reply other threads:[~2012-09-02 10:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-02 10:21 [PATCH 0/6] unicore32: Move PWM driver to PWM framework Thierry Reding
2012-09-02 10:21 ` Thierry Reding [this message]
2012-09-06 8:38 ` [PATCH 1/6] unicore32: pwm: Properly remap memory-mapped registers guanxuetao
2012-09-07 12:50 ` Thierry Reding
2012-09-02 10:21 ` [PATCH 2/6] unicore32: pwm: Use module_platform_driver() Thierry Reding
2012-09-02 10:21 ` [PATCH 3/6] unicore32: pwm: Remove unnecessary indirection Thierry Reding
2012-09-02 10:21 ` [PATCH 4/6] unicore32: Add common clock support Thierry Reding
2012-09-06 8:42 ` guanxuetao
2012-09-07 12:53 ` Thierry Reding
2012-09-08 1:22 ` Mike Turquette
2012-09-02 10:21 ` [PATCH 5/6] unicore32: pwm: Use managed resource allocations Thierry Reding
2012-09-02 10:21 ` [PATCH 6/6] pwm: Move PUV3 PWM driver to PWM framework Thierry Reding
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1346581273-7041-2-git-send-email-thierry.reding@avionic-design.de \
--to=thierry.reding@avionic-design.de \
--cc=gxt@mprc.pku.edu.cn \
--cc=linux-kernel@vger.kernel.org \
--cc=mturquette@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).