+++ /dev/null
-From 5cd5a44b94b451ecaf593bb49919cfbb51ccb622 Mon Sep 17 00:00:00 2001
-From: Lars-Peter Clausen <lars@metafoo.de>
-Date: Sat, 17 Jul 2010 11:12:20 +0000
-Subject: [PATCH] MIPS: JZ4740: Add PWM support
-
-Add support for the PWM part of the timer unit on a JZ4740 SoC.
-
-Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
-Cc: linux-mips@linux-mips.org
-Cc: linux-kernel@vger.kernel.org
-Patchwork: https://patchwork.linux-mips.org/patch/1468/
-Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
----
- arch/mips/jz4740/pwm.c | 177 ++++++++++++++++++++++++++++++++++++++++++++++++
- 1 files changed, 177 insertions(+), 0 deletions(-)
- create mode 100644 arch/mips/jz4740/pwm.c
-
---- /dev/null
-+++ b/arch/mips/jz4740/pwm.c
-@@ -0,0 +1,177 @@
-+/*
-+ * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
-+ * JZ4740 platform PWM support
-+ *
-+ * 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.
-+ *
-+ * 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.,
-+ * 675 Mass Ave, Cambridge, MA 02139, USA.
-+ *
-+ */
-+
-+#include <linux/kernel.h>
-+
-+#include <linux/clk.h>
-+#include <linux/err.h>
-+#include <linux/pwm.h>
-+#include <linux/gpio.h>
-+
-+#include <asm/mach-jz4740/gpio.h>
-+#include "timer.h"
-+
-+static struct clk *jz4740_pwm_clk;
-+
-+DEFINE_MUTEX(jz4740_pwm_mutex);
-+
-+struct pwm_device {
-+ unsigned int id;
-+ unsigned int gpio;
-+ bool used;
-+};
-+
-+static struct pwm_device jz4740_pwm_list[] = {
-+ { 2, JZ_GPIO_PWM2, false },
-+ { 3, JZ_GPIO_PWM3, false },
-+ { 4, JZ_GPIO_PWM4, false },
-+ { 5, JZ_GPIO_PWM5, false },
-+ { 6, JZ_GPIO_PWM6, false },
-+ { 7, JZ_GPIO_PWM7, false },
-+};
-+
-+struct pwm_device *pwm_request(int id, const char *label)
-+{
-+ int ret = 0;
-+ struct pwm_device *pwm;
-+
-+ if (id < 2 || id > 7 || !jz4740_pwm_clk)
-+ return ERR_PTR(-ENODEV);
-+
-+ mutex_lock(&jz4740_pwm_mutex);
-+
-+ pwm = &jz4740_pwm_list[id - 2];
-+ if (pwm->used)
-+ ret = -EBUSY;
-+ else
-+ pwm->used = true;
-+
-+ mutex_unlock(&jz4740_pwm_mutex);
-+
-+ if (ret)
-+ return ERR_PTR(ret);
-+
-+ ret = gpio_request(pwm->gpio, label);
-+
-+ if (ret) {
-+ printk(KERN_ERR "Failed to request pwm gpio: %d\n", ret);
-+ pwm->used = false;
-+ return ERR_PTR(ret);
-+ }
-+
-+ jz_gpio_set_function(pwm->gpio, JZ_GPIO_FUNC_PWM);
-+
-+ jz4740_timer_start(id);
-+
-+ return pwm;
-+}
-+
-+void pwm_free(struct pwm_device *pwm)
-+{
-+ pwm_disable(pwm);
-+ jz4740_timer_set_ctrl(pwm->id, 0);
-+
-+ jz_gpio_set_function(pwm->gpio, JZ_GPIO_FUNC_NONE);
-+ gpio_free(pwm->gpio);
-+
-+ jz4740_timer_stop(pwm->id);
-+
-+ pwm->used = false;
-+}
-+
-+int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
-+{
-+ unsigned long long tmp;
-+ unsigned long period, duty;
-+ unsigned int prescaler = 0;
-+ unsigned int id = pwm->id;
-+ uint16_t ctrl;
-+ bool is_enabled;
-+
-+ if (duty_ns < 0 || duty_ns > period_ns)
-+ return -EINVAL;
-+
-+ tmp = (unsigned long long)clk_get_rate(jz4740_pwm_clk) * period_ns;
-+ do_div(tmp, 1000000000);
-+ period = tmp;
-+
-+ while (period > 0xffff && prescaler < 6) {
-+ period >>= 2;
-+ ++prescaler;
-+ }
-+
-+ if (prescaler == 6)
-+ return -EINVAL;
-+
-+ tmp = (unsigned long long)period * duty_ns;
-+ do_div(tmp, period_ns);
-+ duty = period - tmp;
-+
-+ if (duty >= period)
-+ duty = period - 1;
-+
-+ is_enabled = jz4740_timer_is_enabled(id);
-+ if (is_enabled)
-+ pwm_disable(pwm);
-+
-+ jz4740_timer_set_count(id, 0);
-+ jz4740_timer_set_duty(id, duty);
-+ jz4740_timer_set_period(id, period);
-+
-+ ctrl = JZ_TIMER_CTRL_PRESCALER(prescaler) | JZ_TIMER_CTRL_SRC_EXT |
-+ JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;
-+
-+ jz4740_timer_set_ctrl(id, ctrl);
-+
-+ if (is_enabled)
-+ pwm_enable(pwm);
-+
-+ return 0;
-+}
-+
-+int pwm_enable(struct pwm_device *pwm)
-+{
-+ uint32_t ctrl = jz4740_timer_get_ctrl(pwm->id);
-+
-+ ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
-+ jz4740_timer_set_ctrl(pwm->id, ctrl);
-+ jz4740_timer_enable(pwm->id);
-+
-+ return 0;
-+}
-+
-+void pwm_disable(struct pwm_device *pwm)
-+{
-+ uint32_t ctrl = jz4740_timer_get_ctrl(pwm->id);
-+
-+ ctrl &= ~JZ_TIMER_CTRL_PWM_ENABLE;
-+ jz4740_timer_disable(pwm->id);
-+ jz4740_timer_set_ctrl(pwm->id, ctrl);
-+}
-+
-+static int __init jz4740_pwm_init(void)
-+{
-+ int ret = 0;
-+
-+ jz4740_pwm_clk = clk_get(NULL, "ext");
-+
-+ if (IS_ERR(jz4740_pwm_clk)) {
-+ ret = PTR_ERR(jz4740_pwm_clk);
-+ jz4740_pwm_clk = NULL;
-+ }
-+
-+ return ret;
-+}
-+subsys_initcall(jz4740_pwm_init);
projects / openwrt.git / blobdiff