Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d1b68865 authored by Thierry Reding's avatar Thierry Reding
Browse files

unicore32: pwm: Properly remap memory-mapped registers 



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: default avatarThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: default avatarGuan Xuetao <gxt@mprc.pku.edu.cn>
Tested-by: default avatarQin Rui <qinrui@mprc.pku.edu.cn>
parent 60ce7028

arch/unicore32/include/mach/regs-ost.h

+8 −10
Original line number Diff line number Diff line
@@ -33,18 +33,16 @@ 
 * Interrupt Enable Reg OST_OIER

 */

#define OST_OIER	(PKUNITY_OST_BASE + 0x001C)



/*

 * PWM Pulse Width Control Reg OST_PWMPWCR

 */

#define OST_PWMPWCR	(PKUNITY_OST_BASE + 0x0080)

/*

 * PWM Duty Cycle Control Reg OST_PWMDCCR

 */

#define OST_PWMDCCR	(PKUNITY_OST_BASE + 0x0084)

/*

 * PWM Period Control Reg OST_PWMPCR

 * PWM Registers: IO base address: PKUNITY_OST_BASE + 0x80

 *      PWCR: Pulse Width Control Reg

 *      DCCR: Duty Cycle Control Reg

 *      PCR: Period Control Reg

 */

#define OST_PWMPCR	(PKUNITY_OST_BASE + 0x0088)

#define OST_PWM_PWCR	(0x00)

#define OST_PWM_DCCR	(0x04)

#define OST_PWM_PCR 	(0x08)



/*

 * Match detected 0 OST_OSSR_M0

arch/unicore32/kernel/pwm.c

+18 −3
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ 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 +71,11 @@ 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 + OST_PWM_PWCR);

	writel(pv - dc, pwm->base + OST_PWM_DCCR);

	writel(pv, pwm->base + OST_PWM_PCR);



	clk_disable(pwm->clk);



	return 0;
@@ -190,10 +194,19 @@ 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 +237,8 @@ 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));