Dear Donghwa Lee,
On Tue, Mar 8, 2011 at 7:12 AM, Donghwa Lee dh09.lee@samsung.com wrote:
This is common pwm driver of S5P.
Signed-off-by: Donghwa Lee dh09.lee@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com
Changes since v2:
- Timer4 was blocked to access compare buffer register
- code clean
arch/arm/cpu/armv7/s5p-common/Makefile | 1 + arch/arm/cpu/armv7/s5p-common/pwm.c | 198 +++++++++++++++++++++++++++++++ arch/arm/include/asm/arch-s5pc1xx/pwm.h | 7 + arch/arm/include/asm/arch-s5pc2xx/pwm.h | 7 + include/pwm.h | 31 +++++ 5 files changed, 244 insertions(+), 0 deletions(-) create mode 100644 arch/arm/cpu/armv7/s5p-common/pwm.c create mode 100644 include/pwm.h
diff --git a/arch/arm/cpu/armv7/s5p-common/Makefile b/arch/arm/cpu/armv7/s5p-common/Makefile index 922cd95..ce0a41e 100644 --- a/arch/arm/cpu/armv7/s5p-common/Makefile +++ b/arch/arm/cpu/armv7/s5p-common/Makefile @@ -27,6 +27,7 @@ LIB = $(obj)libs5p-common.o
COBJS-y += cpu_info.o COBJS-y += timer.o +COBJS-$(CONFIG_PWM) += pwm.o
SRCS := $(SOBJS:.o=.S) $(COBJS:.o=.c) OBJS := $(addprefix $(obj),$(COBJS-y) $(SOBJS)) diff --git a/arch/arm/cpu/armv7/s5p-common/pwm.c b/arch/arm/cpu/armv7/s5p-common/pwm.c new file mode 100644 index 0000000..29e996e --- /dev/null +++ b/arch/arm/cpu/armv7/s5p-common/pwm.c @@ -0,0 +1,198 @@ +/*
- Copyright (C) 2011 Samsung Electronics
- Donghwa Lee dh09.lee@samsung.com
- See file CREDITS for list of people who contributed to this
- project.
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of
- the License, or (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- MA 02111-1307 USA
- */
+#include <common.h> +#include <errno.h> +#include <pwm.h> +#include <asm/io.h> +#include <asm/arch/pwm.h> +#include <asm/arch/clk.h>
+#define PRESCALER_0 (8 - 1) /* prescaler of timer 0, 1 */ +#define PRESCALER_1 (16 - 1) /* prescaler of timer 2, 3, 4 */ +#define MUX_DIV_1 0 /* 1/1 period */ +#define MUX_DIV_2 1 /* 1/2 period */ +#define MUX_DIV_4 2 /* 1/4 period */ +#define MUX_DIV_8 3 /* 1/8 period */ +#define MUX_DIV_16 4 /* 1/16 period */
+#define MUX_DIV_SHIFT(x) (x * 4)
+int pwm_enable(int pwm_id) +{
- const struct s5p_timer *pwm =
- (struct s5p_timer *)samsung_get_base_timer();
- unsigned long tcon;
- tcon = readl(&pwm->tcon);
- tcon |= TCON_START(pwm_id);
- writel(tcon, &pwm->tcon);
- return 0;
+}
+void pwm_disable(int pwm_id) +{
- const struct s5p_timer *pwm =
- (struct s5p_timer *)samsung_get_base_timer();
- unsigned long tcon;
- tcon = readl(&pwm->tcon);
- tcon &= ~TCON_START(pwm_id);
- writel(tcon, &pwm->tcon);
+}
+static unsigned long pwm_calc_tin(int pwm_id, unsigned long freq) +{
- unsigned long tin_parent_rate;
- unsigned int div;
- tin_parent_rate = get_pwm_clk();
- for (div = 2; div <= 16; div *= 2) {
- if ((tin_parent_rate / (div << 16)) < freq)
- return tin_parent_rate / div;
- }
- return tin_parent_rate / 16;
+}
+#define NS_IN_HZ (1000000000UL)
+int pwm_config(int pwm_id, int duty_ns, int period_ns) +{
- const struct s5p_timer *pwm =
- (struct s5p_timer *)samsung_get_base_timer();
- unsigned int offset;
- unsigned long tin_rate;
- unsigned long tin_ns;
- unsigned long period;
- unsigned long tcon;
- unsigned long tcnt;
- unsigned long timer_rate_hz;
- unsigned long tcmp;
- /*
- * We currently avoid using 64bit arithmetic by using the
- * fact that anything faster than 1GHz is easily representable
- * by 32bits.
- */
- if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ)
- return -ERANGE;
- if (duty_ns > period_ns)
- return -EINVAL;
- period = NS_IN_HZ / period_ns;
periad_ns = 0; This leads to divide by zero. How divede by zero is handeled.
- /* Check to see if we are changing the clock rate of the PWM */
- tin_rate = pwm_calc_tin(pwm_id, period);
- timer_rate_hz = tin_rate;
- tin_ns = NS_IN_HZ / tin_rate;
- tcnt = period_ns / tin_ns;
- /* Note, counters count down */
- tcmp = duty_ns / tin_ns;
- tcmp = tcnt - tcmp;
- /*
- * the pwm hw only checks the compare register after a decrement,
- * so the pin never toggles if tcmp = tcnt
- */
- if (tcmp == tcnt)
- tcmp--;
- if (tcmp < 0)
- tcmp = 0;
- /* Update the PWM register block. */
- offset = pwm_id * 0xc;
- writel(tcnt, &pwm->tcntb0 + offset);
- if (pwm_id < 4)
- writel(tcmp, &pwm->tcmpb0 + offset);
- tcon = readl(&pwm->tcon);
- tcon |= TCON_UPDATE(pwm_id);
- if (pwm_id < 4)
- tcon |= TCON_AUTO_RELOAD(pwm_id);
- else
- tcon |= TCON4_AUTO_RELOAD;
- writel(tcon, &pwm->tcon);
- tcon &= ~TCON_UPDATE(pwm_id);
- writel(tcon, &pwm->tcon);
- return 0;
+}
+int pwm_init(int pwm_id, int div, int invert) +{
- u32 val;
- const struct s5p_timer *pwm =
- (struct s5p_timer *)samsung_get_base_timer();
- unsigned long timer_rate_hz;
- unsigned int offset, prescaler;
- /*
- * Timer Freq(HZ) =
- * PWM_CLK / { (prescaler_value + 1) * (divider_value) }
- */
- val = readl(&pwm->tcfg0);
- if (pwm_id < 2) {
- prescaler = PRESCALER_0;
- val &= ~0xff;
- val |= (prescaler & 0xff);
- } else {
- prescaler = PRESCALER_1;
- val &= ~(0xff << 8);
- val |= (prescaler & 0xff) << 8;
- }
- writel(val, &pwm->tcfg0);
- val = readl(&pwm->tcfg1);
- val &= ~(0xf << MUX_DIV_SHIFT(pwm_id));
- val |= (div & 0xf) << MUX_DIV_SHIFT(pwm_id);
- writel(val, &pwm->tcfg1);
- timer_rate_hz = get_pwm_clk() / ((prescaler + 1) *
- (div + 1));
- timer_rate_hz = timer_rate_hz / 100;
- /* set count value */
- offset = pwm_id * 0xc;
- writel(timer_rate_hz, &pwm->tcntb0 + offset);
- val = readl(&pwm->tcon) & ~(0xf << TCON_OFFSET(pwm_id));
- if (invert && (pwm_id < 4))
- val |= TCON_INVERTER(pwm_id);
- writel(val, &pwm->tcon);
- pwm_enable(pwm_id);
- return 0;
+} diff --git a/arch/arm/include/asm/arch-s5pc1xx/pwm.h b/arch/arm/include/asm/arch-s5pc1xx/pwm.h index 0369968..ec62075 100644 --- a/arch/arm/include/asm/arch-s5pc1xx/pwm.h +++ b/arch/arm/include/asm/arch-s5pc1xx/pwm.h @@ -29,6 +29,13 @@ /* start bit of PWM Timer 4 */ #define TCON4_START (1 << 20)
+#define TCON_OFFSET(x) ((x + 1) * (!!x) << 2)
+#define TCON_START(x) (1 << TCON_OFFSET(x)) +#define TCON_UPDATE(x) (1 << (TCON_OFFSET(x) + 1)) +#define TCON_INVERTER(x) (1 << (TCON_OFFSET(x) + 2)) +#define TCON_AUTO_RELOAD(x) (1 << (TCON_OFFSET(x) + 3))
#ifndef __ASSEMBLY__ struct s5p_timer { unsigned int tcfg0; diff --git a/arch/arm/include/asm/arch-s5pc2xx/pwm.h b/arch/arm/include/asm/arch-s5pc2xx/pwm.h index 0369968..ec62075 100644 --- a/arch/arm/include/asm/arch-s5pc2xx/pwm.h +++ b/arch/arm/include/asm/arch-s5pc2xx/pwm.h @@ -29,6 +29,13 @@ /* start bit of PWM Timer 4 */ #define TCON4_START (1 << 20)
+#define TCON_OFFSET(x) ((x + 1) * (!!x) << 2)
+#define TCON_START(x) (1 << TCON_OFFSET(x)) +#define TCON_UPDATE(x) (1 << (TCON_OFFSET(x) + 1)) +#define TCON_INVERTER(x) (1 << (TCON_OFFSET(x) + 2)) +#define TCON_AUTO_RELOAD(x) (1 << (TCON_OFFSET(x) + 3))
#ifndef __ASSEMBLY__ struct s5p_timer { unsigned int tcfg0; diff --git a/include/pwm.h b/include/pwm.h new file mode 100644 index 0000000..13acf85 --- /dev/null +++ b/include/pwm.h @@ -0,0 +1,31 @@ +/*
- header file for pwm driver.
- Copyright (c) 2011 samsung electronics
- Donghwa Lee dh09.lee@samsung.com
- This program is free software; you can redistribute it and/or
- modify it under the terms of the GNU General Public License as
- published by the Free Software Foundation; either version 2 of
- the License, or (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston,
- MA 02111-1307 USA
- */
+#ifndef _pwm_h_ +#define _pwm_h_
+int pwm_init (int pwm_id, int div, int invert); +int pwm_config (int pwm_id, int duty_ns, int period_ns); +int pwm_enable (int pwm_id); +void pwm_disable (int pwm_id);
+#endif /* _pwm_h_ */
1.6.0.4
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