summaryrefslogtreecommitdiffstats
path: root/qemu/roms/u-boot/arch/arm/cpu/armv7/s5p-common/pwm.c
diff options
context:
space:
mode:
Diffstat (limited to 'qemu/roms/u-boot/arch/arm/cpu/armv7/s5p-common/pwm.c')
-rw-r--r--qemu/roms/u-boot/arch/arm/cpu/armv7/s5p-common/pwm.c171
1 files changed, 171 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/arch/arm/cpu/armv7/s5p-common/pwm.c b/qemu/roms/u-boot/arch/arm/cpu/armv7/s5p-common/pwm.c
new file mode 100644
index 000000000..b8805c8d4
--- /dev/null
+++ b/qemu/roms/u-boot/arch/arm/cpu/armv7/s5p-common/pwm.c
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2011 Samsung Electronics
+ *
+ * Donghwa Lee <dh09.lee@samsung.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#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_SEC 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 frequency;
+ unsigned long tcon;
+ unsigned long tcnt;
+ 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_SEC || duty_ns > NS_IN_SEC || period_ns == 0)
+ return -ERANGE;
+
+ if (duty_ns > period_ns)
+ return -EINVAL;
+
+ frequency = NS_IN_SEC / period_ns;
+
+ /* Check to see if we are changing the clock rate of the PWM */
+ tin_rate = pwm_calc_tin(pwm_id, frequency);
+
+ tin_ns = NS_IN_SEC / tin_rate;
+ tcnt = period_ns / tin_ns;
+
+ /* Note, counters count down */
+ tcmp = duty_ns / tin_ns;
+ tcmp = tcnt - tcmp;
+
+ /* 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 ticks_per_period;
+ 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);
+
+ if (pwm_id == 4) {
+ /*
+ * TODO(sjg): Use this as a countdown timer for now. We count
+ * down from the maximum value to 0, then reset.
+ */
+ ticks_per_period = -1UL;
+ } else {
+ const unsigned long pwm_hz = 1000;
+ unsigned long timer_rate_hz = get_pwm_clk() /
+ ((prescaler + 1) * (1 << div));
+
+ ticks_per_period = timer_rate_hz / pwm_hz;
+ }
+
+ /* set count value */
+ offset = pwm_id * 3;
+
+ writel(ticks_per_period, &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;
+}