[U-Boot] [PATCH v4] ARM: S5P: pwm driver support
Donghwa Lee
dh09.lee at samsung.com
Tue Mar 8 08:11:42 CET 2011
This is common pwm driver of S5P.
Signed-off-by: Donghwa Lee <dh09.lee at samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
---
Changes since v3:
- fixed pwm register offset
- move definitions of register to header file
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 | 189 +++++++++++++++++++++++++++++++
arch/arm/include/asm/arch-s5pc1xx/pwm.h | 19 +++
arch/arm/include/asm/arch-s5pc2xx/pwm.h | 19 +++
include/pwm.h | 31 +++++
5 files changed, 259 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..ff95b84
--- /dev/null
+++ b/arch/arm/cpu/armv7/s5p-common/pwm.c
@@ -0,0 +1,189 @@
+/*
+ * Copyright (C) 2011 Samsung Electronics
+ *
+ * Donghwa Lee <dh09.lee at 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>
+
+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;
+
+ /* 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 * 3;
+ if (pwm_id < 4) {
+ writel(tcnt, &pwm->tcntb0 + offset);
+ 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 * 3;
+ 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..de4dbce 100644
--- a/arch/arm/include/asm/arch-s5pc1xx/pwm.h
+++ b/arch/arm/include/asm/arch-s5pc1xx/pwm.h
@@ -22,6 +22,18 @@
#ifndef __ASM_ARM_ARCH_PWM_H_
#define __ASM_ARM_ARCH_PWM_H_
+#define PRESCALER_0 (8 - 1) /* prescaler of timer 0, 1 */
+#define PRESCALER_1 (16 - 1) /* prescaler of timer 2, 3, 4 */
+
+/* Divider MUX */
+#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)
+
/* Interval mode(Auto Reload) of PWM Timer 4 */
#define TCON4_AUTO_RELOAD (1 << 22)
/* Update TCNTB4 */
@@ -29,6 +41,13 @@
/* 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..de4dbce 100644
--- a/arch/arm/include/asm/arch-s5pc2xx/pwm.h
+++ b/arch/arm/include/asm/arch-s5pc2xx/pwm.h
@@ -22,6 +22,18 @@
#ifndef __ASM_ARM_ARCH_PWM_H_
#define __ASM_ARM_ARCH_PWM_H_
+#define PRESCALER_0 (8 - 1) /* prescaler of timer 0, 1 */
+#define PRESCALER_1 (16 - 1) /* prescaler of timer 2, 3, 4 */
+
+/* Divider MUX */
+#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)
+
/* Interval mode(Auto Reload) of PWM Timer 4 */
#define TCON4_AUTO_RELOAD (1 << 22)
/* Update TCNTB4 */
@@ -29,6 +41,13 @@
/* 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 at 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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