1 files changed, 170 insertions, 0 deletions

diff --git a/firmware/target/mips/ingenic_x1000/pwm-x1000.c b/firmware/target/mips/ingenic_x1000/pwm-x1000.c
new file mode 100644
index 0000000000..37d2856c1a
--- /dev/null
+++ b/firmware/target/mips/ingenic_x1000/pwm-x1000.c
@@ -0,0 +1,170 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2021 Aidan MacDonald
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "pwm-x1000.h"
+#include "clk-x1000.h"
+#include "gpio-x1000.h"
+#include "system.h"
+#include "kernel.h"
+#include "x1000/tcu.h"
+
+struct pwm_gpio_data {
+    int port;
+    unsigned pin;
+    int func;
+};
+
+struct pwm_state {
+    struct pwm_gpio_data gpio;
+    int period_ns;
+    int duty_ns;
+    int full_ticks;
+    int half_ticks;
+    int prescaler;
+};
+
+static struct pwm_state pwm_state[] = {
+    {{GPIO_C, 1 << 25, GPIO_DEVICE(0)}, -1, -1, -1, -1, -1},
+    {{GPIO_C, 1 << 26, GPIO_DEVICE(1)}, -1, -1, -1, -1, -1},
+    {{GPIO_C, 1 << 27, GPIO_DEVICE(1)}, -1, -1, -1, -1, -1},
+    {{GPIO_B, 1 <<  6, GPIO_DEVICE(2)}, -1, -1, -1, -1, -1},
+    {{GPIO_C, 1 << 24, GPIO_DEVICE(0)}, -1, -1, -1, -1, -1},
+};
+
+void pwm_init(int chn)
+{
+    /* clear cached state */
+    struct pwm_state* st = &pwm_state[chn];
+    st->period_ns = -1;
+    st->duty_ns = -1;
+    st->full_ticks = -1;
+    st->prescaler = -1;
+    st->prescaler = -1;
+
+    /* clear GPIO and disable timer */
+    gpio_config(st->gpio.port, st->gpio.pin, GPIO_OUTPUT(0));
+    jz_clr(TCU_STOP, 1 << chn);
+    jz_clr(TCU_ENABLE, 1 << chn);
+    jz_set(TCU_STOP, 1 << chn);
+}
+
+void pwm_set_period(int chn, int period_ns, int duty_ns)
+{
+    struct pwm_state* st = &pwm_state[chn];
+    unsigned long long tmp;
+    int full_ticks = st->full_ticks;
+    int half_ticks = st->half_ticks;
+    int prescaler = st->prescaler;
+
+    if(period_ns != st->period_ns) {
+        /* calculate full tick period and prescaler */
+        tmp = clk_get(X1000_CLK_PCLK) / 1000000;
+        tmp *= period_ns;
+        tmp /= 1000;
+
+        prescaler = 0;
+        while(tmp > 0xffff && prescaler < 5) {
+            tmp /= 4;
+            prescaler += 1;
+        }
+
+        full_ticks = (tmp > 0xffff) ? 0xffff : tmp;
+        st->period_ns = period_ns;
+    }
+
+    if(duty_ns != st->duty_ns) {
+        /* calculate half tick value */
+        tmp = full_ticks;
+        tmp *= duty_ns;
+        tmp /= period_ns;
+
+        half_ticks = (tmp > 0xffff) ? 0xffff : tmp;
+        if(half_ticks >= full_ticks)
+            half_ticks = full_ticks - 1;
+        st->duty_ns = duty_ns;
+    }
+
+    /* need to clear STOP bit to access timer unit registers */
+    int was_stopped = !!(jz_read(TCU_STOP) & (1 << chn));
+    if(was_stopped)
+        jz_clr(TCU_STOP, 1 << chn);
+
+    /* check if timer is currently running */
+    int was_enabled = !!(jz_read(TCU_ENABLE) & (1 << chn));
+    int enabled = was_enabled;
+
+    if(prescaler != st->prescaler) {
+        /* must disable timer to change these settings */
+        if(was_enabled) {
+            jz_clr(TCU_ENABLE, 1 << chn);
+            enabled = 0;
+        }
+
+        jz_overwritef(TCU_CTRL(chn), SHUTDOWN_V(GRACEFUL), INIT_LVL(0),
+                      PWM_EN(1), PRESCALE(prescaler), SOURCE_V(PCLK));
+        REG_TCU_COUNT(chn) = 0;
+        st->prescaler = prescaler;
+    }
+
+    if(full_ticks != st->full_ticks || half_ticks != st->half_ticks) {
+        if(enabled) {
+            /* avoid changing PWM settings in the middle of a cycle */
+            unsigned cmp = REG_TCU_CMP_FULL(chn) - 1;
+            long deadline = current_tick + 3;
+            while(REG_TCU_COUNT(chn) < cmp
+               && TIME_BEFORE(current_tick, deadline));
+        }
+
+        /* these can be changed while the timer is running */
+        REG_TCU_CMP_FULL(chn) = full_ticks;
+        REG_TCU_CMP_HALF(chn) = full_ticks - half_ticks;
+        st->full_ticks = full_ticks;
+        st->half_ticks = half_ticks;
+    }
+
+    /* restore the enable/stop state */
+    if(was_enabled && !enabled)
+        jz_set(TCU_ENABLE, 1 << chn);
+    if(was_stopped)
+        jz_set(TCU_STOP, 1 << chn);
+}
+
+void pwm_enable(int chn)
+{
+    /* Start timer */
+    jz_clr(TCU_STOP, 1 << chn);
+    jz_set(TCU_ENABLE, 1 << chn);
+
+    /* Configure GPIO function */
+    struct pwm_state* st = &pwm_state[chn];
+    gpio_config(st->gpio.port, st->gpio.pin, st->gpio.func);
+}
+
+void pwm_disable(int chn)
+{
+    /* Set GPIO to output 0 */
+    struct pwm_state* st = &pwm_state[chn];
+    gpio_config(st->gpio.port, st->gpio.pin, GPIO_OUTPUT(0));
+
+    /* Stop timer */
+    jz_clr(TCU_ENABLE, 1 << chn);
+    jz_set(TCU_STOP, 1 << chn);
+}