Commit b2f97cf2 authored by Heiko Schocher's avatar Heiko Schocher Committed by Stefano Babic

pwm, imx6: add support for pwm modul on imx6

add basic support for the pwm modul found on imx6.
Pieces of this code are based on linux code from drivers/pwm/pwm-imx.c
Commit "cd3de83f1476 Linux 3.16-rc4"
Signed-off-by: default avatarHeiko Schocher <hs@denx.de>
Acked-by: default avatarStefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
parent aafe4020
......@@ -1377,6 +1377,10 @@ The following options need to be configured:
CONFIG_SH_ETHER_CACHE_WRITEBACK
If this option is set, the driver enables cache flush.
- PWM Support:
CONFIG_PWM_IMX
Support for PWM modul on the imx6.
- TPM Support:
CONFIG_TPM
Support TPM devices.
......
......@@ -15,3 +15,4 @@ obj-y += video/
obj-y += watchdog/
obj-$(CONFIG_QE) += qe/
obj-y += memory/
obj-y += pwm/
#
# (C) Copyright 2006
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
# (C) Copyright 2001
# Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
#
# SPDX-License-Identifier: GPL-2.0+
#
#ccflags-y += -DDEBUG
obj-$(CONFIG_PWM_IMX) += pwm-imx.o pwm-imx-util.o
/*
* (C) Copyright 2014
* Heiko Schocher, DENX Software Engineering, hs@denx.de.
*
* Basic support for the pwm modul on imx6.
*
* Based on linux:drivers/pwm/pwm-imx.c
* from
* Sascha Hauer <s.hauer@pengutronix.de>
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <common.h>
#include <div64.h>
#include <asm/arch/imx-regs.h>
/* pwm_id from 0..3 */
struct pwm_regs *pwm_id_to_reg(int pwm_id)
{
switch (pwm_id) {
case 0:
return (struct pwm_regs *)PWM1_BASE_ADDR;
break;
case 1:
return (struct pwm_regs *)PWM2_BASE_ADDR;
break;
case 2:
return (struct pwm_regs *)PWM3_BASE_ADDR;
break;
case 3:
return (struct pwm_regs *)PWM4_BASE_ADDR;
break;
default:
printf("unknown pwm_id: %d\n", pwm_id);
break;
}
return NULL;
}
int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c,
unsigned long *duty_c, unsigned long *prescale)
{
unsigned long long c;
/*
* we have not yet a clock framework for imx6, so add the clock
* value here as a define. Replace it when we have the clock
* framework.
*/
c = CONFIG_IMX6_PWM_PER_CLK;
c = c * period_ns;
do_div(c, 1000000000);
*period_c = c;
*prescale = *period_c / 0x10000 + 1;
*period_c /= *prescale;
c = (unsigned long long)(*period_c * duty_ns);
do_div(c, period_ns);
*duty_c = c;
/*
* according to imx pwm RM, the real period value should be
* PERIOD value in PWMPR plus 2.
*/
if (*period_c > 2)
*period_c -= 2;
else
*period_c = 0;
return 0;
}
/*
* (C) Copyright 2014
* Heiko Schocher, DENX Software Engineering, hs@denx.de.
*
* Basic support for the pwm modul on imx6.
*
* SPDX-License-Identifier: GPL-2.0
*/
#ifndef _pwm_imx_util_h_
#define _pwm_imx_util_h_
struct pwm_regs *pwm_id_to_reg(int pwm_id);
int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c,
unsigned long *duty_c, unsigned long *prescale);
#endif
/*
* (C) Copyright 2014
* Heiko Schocher, DENX Software Engineering, hs@denx.de.
*
* Basic support for the pwm modul on imx6.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <div64.h>
#include <pwm.h>
#include <asm/arch/imx-regs.h>
#include <asm/io.h>
#include "pwm-imx-util.h"
int pwm_init(int pwm_id, int div, int invert)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
writel(0, &pwm->ir);
return 0;
}
int pwm_config(int pwm_id, int duty_ns, int period_ns)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
unsigned long period_cycles, duty_cycles, prescale;
u32 cr;
pwm_imx_get_parms(period_ns, duty_ns, &period_cycles, &duty_cycles,
&prescale);
cr = PWMCR_PRESCALER(prescale) |
PWMCR_DOZEEN | PWMCR_WAITEN |
PWMCR_DBGEN | PWMCR_CLKSRC_IPG_HIGH;
writel(cr, &pwm->cr);
/* set duty cycles */
writel(duty_cycles, &pwm->sar);
/* set period cycles */
writel(period_cycles, &pwm->pr);
return 0;
}
int pwm_enable(int pwm_id)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
setbits_le32(&pwm->cr, PWMCR_EN);
return 0;
}
void pwm_disable(int pwm_id)
{
struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
clrbits_le32(&pwm->cr, PWMCR_EN);
}
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