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-rw-r--r--arch/arm/plat-s3c/pwm.c288
1 files changed, 288 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c/pwm.c b/arch/arm/plat-s3c/pwm.c
new file mode 100644
index 00000000000..250bd2bc9b8
--- /dev/null
+++ b/arch/arm/plat-s3c/pwm.c
@@ -0,0 +1,288 @@
+/*
+ * arch/arm/plat-s3c/pwm.c
+ *
+ * Copyright (c) by Javi Roman <javiroman@kernel-labs.org>
+ * for the Openmoko Project.
+ *
+ * S3C2410A SoC 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <mach/hardware.h>
+#include <plat/regs-timer.h>
+#include <plat/pwm.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_PM
+ static unsigned long standby_reg_tcon;
+ static unsigned long standby_reg_tcfg0;
+ static unsigned long standby_reg_tcfg1;
+#endif
+
+int s3c2410_pwm_disable(struct s3c2410_pwm *pwm)
+{
+ unsigned long tcon;
+
+ /* stop timer */
+ tcon = __raw_readl(S3C2410_TCON);
+ tcon &= 0xffffff00;
+ __raw_writel(tcon, S3C2410_TCON);
+
+ clk_disable(pwm->pclk);
+ clk_put(pwm->pclk);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s3c2410_pwm_disable);
+
+int s3c2410_pwm_init(struct s3c2410_pwm *pwm)
+{
+ pwm->pclk = clk_get(NULL, "timers");
+ if (IS_ERR(pwm->pclk))
+ return PTR_ERR(pwm->pclk);
+
+ clk_enable(pwm->pclk);
+ pwm->pclk_rate = clk_get_rate(pwm->pclk);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s3c2410_pwm_init);
+
+int s3c2410_pwm_enable(struct s3c2410_pwm *pwm)
+{
+ unsigned long tcfg0, tcfg1, tcnt, tcmp;
+
+ /* control registers bits */
+ tcfg1 = __raw_readl(S3C2410_TCFG1);
+ tcfg0 = __raw_readl(S3C2410_TCFG0);
+
+ /* divider & scaler slection */
+ switch (pwm->timerid) {
+ case PWM0:
+ tcfg1 &= ~S3C2410_TCFG1_MUX0_MASK;
+ tcfg0 &= ~S3C2410_TCFG_PRESCALER0_MASK;
+ break;
+ case PWM1:
+ tcfg1 &= ~S3C2410_TCFG1_MUX1_MASK;
+ tcfg0 &= ~S3C2410_TCFG_PRESCALER0_MASK;
+ break;
+ case PWM2:
+ tcfg1 &= ~S3C2410_TCFG1_MUX2_MASK;
+ tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK;
+ break;
+ case PWM3:
+ tcfg1 &= ~S3C2410_TCFG1_MUX3_MASK;
+ tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK;
+ break;
+ case PWM4:
+ /* timer four is not capable of doing PWM */
+ break;
+ default:
+ clk_disable(pwm->pclk);
+ clk_put(pwm->pclk);
+ return -1;
+ }
+
+ /* divider & scaler values */
+ tcfg1 |= pwm->divider;
+ __raw_writel(tcfg1, S3C2410_TCFG1);
+
+ switch (pwm->timerid) {
+ case PWM0:
+ case PWM1:
+ tcfg0 |= pwm->prescaler;
+ __raw_writel(tcfg0, S3C2410_TCFG0);
+ break;
+ default:
+ if ((tcfg0 | pwm->prescaler) != tcfg0) {
+ printk(KERN_WARNING "not changing prescaler of PWM %u,"
+ " since it's shared with timer4 (clock tick)\n",
+ pwm->timerid);
+ }
+ break;
+ }
+
+ /* timer count and compare buffer initial values */
+ tcnt = pwm->counter;
+ tcmp = pwm->comparer;
+
+ __raw_writel(tcnt, S3C2410_TCNTB(pwm->timerid));
+ __raw_writel(tcmp, S3C2410_TCMPB(pwm->timerid));
+
+ /* ensure timer is stopped */
+ s3c2410_pwm_stop(pwm);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s3c2410_pwm_enable);
+
+int s3c2410_pwm_start(struct s3c2410_pwm *pwm)
+{
+ unsigned long tcon;
+
+ tcon = __raw_readl(S3C2410_TCON);
+
+ switch (pwm->timerid) {
+ case PWM0:
+ tcon |= S3C2410_TCON_T0START;
+ tcon &= ~S3C2410_TCON_T0MANUALUPD;
+ break;
+ case PWM1:
+ tcon |= S3C2410_TCON_T1START;
+ tcon &= ~S3C2410_TCON_T1MANUALUPD;
+ break;
+ case PWM2:
+ tcon |= S3C2410_TCON_T2START;
+ tcon &= ~S3C2410_TCON_T2MANUALUPD;
+ break;
+ case PWM3:
+ tcon |= S3C2410_TCON_T3START;
+ tcon &= ~S3C2410_TCON_T3MANUALUPD;
+ break;
+ case PWM4:
+ /* timer four is not capable of doing PWM */
+ default:
+ return -ENODEV;
+ }
+
+ __raw_writel(tcon, S3C2410_TCON);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s3c2410_pwm_start);
+
+int s3c2410_pwm_stop(struct s3c2410_pwm *pwm)
+{
+ unsigned long tcon;
+
+ tcon = __raw_readl(S3C2410_TCON);
+
+ switch (pwm->timerid) {
+ case PWM0:
+ tcon &= ~0x00000000;
+ tcon |= S3C2410_TCON_T0RELOAD;
+ tcon |= S3C2410_TCON_T0MANUALUPD;
+ break;
+ case PWM1:
+ tcon &= ~0x00000080;
+ tcon |= S3C2410_TCON_T1RELOAD;
+ tcon |= S3C2410_TCON_T1MANUALUPD;
+ break;
+ case PWM2:
+ tcon &= ~0x00000800;
+ tcon |= S3C2410_TCON_T2RELOAD;
+ tcon |= S3C2410_TCON_T2MANUALUPD;
+ break;
+ case PWM3:
+ tcon &= ~0x00008000;
+ tcon |= S3C2410_TCON_T3RELOAD;
+ tcon |= S3C2410_TCON_T3MANUALUPD;
+ break;
+ case PWM4:
+ /* timer four is not capable of doing PWM */
+ default:
+ return -ENODEV;
+ }
+
+ __raw_writel(tcon, S3C2410_TCON);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s3c2410_pwm_stop);
+
+int s3c2410_pwm_duty_cycle(int reg_value, struct s3c2410_pwm *pwm)
+{
+ __raw_writel(reg_value, S3C2410_TCMPB(pwm->timerid));
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s3c2410_pwm_duty_cycle);
+
+int s3c2410_pwm_dumpregs(void)
+{
+ printk(KERN_INFO "TCON: %08lx, TCFG0: %08lx, TCFG1: %08lx\n",
+ (unsigned long) __raw_readl(S3C2410_TCON),
+ (unsigned long) __raw_readl(S3C2410_TCFG0),
+ (unsigned long) __raw_readl(S3C2410_TCFG1));
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(s3c2410_pwm_dumpregs);
+
+static int __init s3c24xx_pwm_probe(struct platform_device *pdev)
+{
+ struct s3c24xx_pwm_platform_data *pdata = pdev->dev.platform_data;
+
+ dev_info(&pdev->dev, "s3c24xx_pwm is registered \n");
+
+ /* if platform was interested, give him a chance to register
+ * platform devices that switch power with us as the parent
+ * at registration time -- ensures suspend / resume ordering
+ */
+ if (pdata)
+ if (pdata->attach_child_devices)
+ (pdata->attach_child_devices)(&pdev->dev);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int s3c24xx_pwm_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ /* PWM config should be kept in suspending */
+ standby_reg_tcon = __raw_readl(S3C2410_TCON);
+ standby_reg_tcfg0 = __raw_readl(S3C2410_TCFG0);
+ standby_reg_tcfg1 = __raw_readl(S3C2410_TCFG1);
+
+ return 0;
+}
+
+static int s3c24xx_pwm_resume(struct platform_device *pdev)
+{
+ __raw_writel(standby_reg_tcon, S3C2410_TCON);
+ __raw_writel(standby_reg_tcfg0, S3C2410_TCFG0);
+ __raw_writel(standby_reg_tcfg1, S3C2410_TCFG1);
+
+ return 0;
+}
+#else
+#define s3c24xx_pwm_suspend NULL
+#define s3c24xx_pwm_resume NULL
+#endif
+
+static struct platform_driver s3c24xx_pwm_driver = {
+ .driver = {
+ .name = "s3c24xx_pwm",
+ .owner = THIS_MODULE,
+ },
+ .probe = s3c24xx_pwm_probe,
+ .suspend = s3c24xx_pwm_suspend,
+ .resume = s3c24xx_pwm_resume,
+};
+
+static int __init s3c24xx_pwm_init(void)
+{
+ return platform_driver_register(&s3c24xx_pwm_driver);
+}
+
+static void __exit s3c24xx_pwm_exit(void)
+{
+}
+
+MODULE_AUTHOR("Javi Roman <javiroman@kernel-labs.org>");
+MODULE_LICENSE("GPL");
+
+module_init(s3c24xx_pwm_init);
+module_exit(s3c24xx_pwm_exit);