Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel...
[pandora-kernel.git] / arch / arm / plat-omap / dmtimer.c
index 75a847d..2def4e1 100644 (file)
@@ -3,6 +3,12 @@
  *
  * OMAP Dual-Mode Timers
  *
+ * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
+ * Tarun Kanti DebBarma <tarun.kanti@ti.com>
+ * Thara Gopinath <thara@ti.com>
+ *
+ * dmtimer adaptation to platform_driver.
+ *
  * Copyright (C) 2005 Nokia Corporation
  * OMAP2 support by Juha Yrjola
  * API improvements and OMAP2 clock framework support by Timo Teras
  * 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/errno.h>
-#include <linux/list.h>
-#include <linux/clk.h>
-#include <linux/delay.h>
 #include <linux/io.h>
-#include <linux/module.h>
-#include <mach/hardware.h>
-#include <plat/dmtimer.h>
-#include <mach/irqs.h>
-
-static int dm_timer_count;
-
-#ifdef CONFIG_ARCH_OMAP1
-static struct omap_dm_timer omap1_dm_timers[] = {
-       { .phys_base = 0xfffb1400, .irq = INT_1610_GPTIMER1 },
-       { .phys_base = 0xfffb1c00, .irq = INT_1610_GPTIMER2 },
-       { .phys_base = 0xfffb2400, .irq = INT_1610_GPTIMER3 },
-       { .phys_base = 0xfffb2c00, .irq = INT_1610_GPTIMER4 },
-       { .phys_base = 0xfffb3400, .irq = INT_1610_GPTIMER5 },
-       { .phys_base = 0xfffb3c00, .irq = INT_1610_GPTIMER6 },
-       { .phys_base = 0xfffb7400, .irq = INT_1610_GPTIMER7 },
-       { .phys_base = 0xfffbd400, .irq = INT_1610_GPTIMER8 },
-};
-
-static const int omap1_dm_timer_count = ARRAY_SIZE(omap1_dm_timers);
-
-#else
-#define omap1_dm_timers                        NULL
-#define omap1_dm_timer_count           0
-#endif /* CONFIG_ARCH_OMAP1 */
-
-#ifdef CONFIG_ARCH_OMAP2
-static struct omap_dm_timer omap2_dm_timers[] = {
-       { .phys_base = 0x48028000, .irq = INT_24XX_GPTIMER1 },
-       { .phys_base = 0x4802a000, .irq = INT_24XX_GPTIMER2 },
-       { .phys_base = 0x48078000, .irq = INT_24XX_GPTIMER3 },
-       { .phys_base = 0x4807a000, .irq = INT_24XX_GPTIMER4 },
-       { .phys_base = 0x4807c000, .irq = INT_24XX_GPTIMER5 },
-       { .phys_base = 0x4807e000, .irq = INT_24XX_GPTIMER6 },
-       { .phys_base = 0x48080000, .irq = INT_24XX_GPTIMER7 },
-       { .phys_base = 0x48082000, .irq = INT_24XX_GPTIMER8 },
-       { .phys_base = 0x48084000, .irq = INT_24XX_GPTIMER9 },
-       { .phys_base = 0x48086000, .irq = INT_24XX_GPTIMER10 },
-       { .phys_base = 0x48088000, .irq = INT_24XX_GPTIMER11 },
-       { .phys_base = 0x4808a000, .irq = INT_24XX_GPTIMER12 },
-};
-
-static const char *omap2_dm_source_names[] __initdata = {
-       "sys_ck",
-       "func_32k_ck",
-       "alt_ck",
-       NULL
-};
-
-static struct clk *omap2_dm_source_clocks[3];
-static const int omap2_dm_timer_count = ARRAY_SIZE(omap2_dm_timers);
-
-#else
-#define omap2_dm_timers                        NULL
-#define omap2_dm_timer_count           0
-#define omap2_dm_source_names          NULL
-#define omap2_dm_source_clocks         NULL
-#endif /* CONFIG_ARCH_OMAP2 */
-
-#ifdef CONFIG_ARCH_OMAP3
-static struct omap_dm_timer omap3_dm_timers[] = {
-       { .phys_base = 0x48318000, .irq = INT_24XX_GPTIMER1 },
-       { .phys_base = 0x49032000, .irq = INT_24XX_GPTIMER2 },
-       { .phys_base = 0x49034000, .irq = INT_24XX_GPTIMER3 },
-       { .phys_base = 0x49036000, .irq = INT_24XX_GPTIMER4 },
-       { .phys_base = 0x49038000, .irq = INT_24XX_GPTIMER5 },
-       { .phys_base = 0x4903A000, .irq = INT_24XX_GPTIMER6 },
-       { .phys_base = 0x4903C000, .irq = INT_24XX_GPTIMER7 },
-       { .phys_base = 0x4903E000, .irq = INT_24XX_GPTIMER8 },
-       { .phys_base = 0x49040000, .irq = INT_24XX_GPTIMER9 },
-       { .phys_base = 0x48086000, .irq = INT_24XX_GPTIMER10 },
-       { .phys_base = 0x48088000, .irq = INT_24XX_GPTIMER11 },
-       { .phys_base = 0x48304000, .irq = INT_34XX_GPT12_IRQ },
-};
-
-static const char *omap3_dm_source_names[] __initdata = {
-       "sys_ck",
-       "omap_32k_fck",
-       NULL
-};
-
-static struct clk *omap3_dm_source_clocks[2];
-static const int omap3_dm_timer_count = ARRAY_SIZE(omap3_dm_timers);
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/pm_runtime.h>
 
-#else
-#define omap3_dm_timers                        NULL
-#define omap3_dm_timer_count           0
-#define omap3_dm_source_names          NULL
-#define omap3_dm_source_clocks         NULL
-#endif /* CONFIG_ARCH_OMAP3 */
-
-#ifdef CONFIG_ARCH_OMAP4
-static struct omap_dm_timer omap4_dm_timers[] = {
-       { .phys_base = 0x4a318000, .irq = OMAP44XX_IRQ_GPT1 },
-       { .phys_base = 0x48032000, .irq = OMAP44XX_IRQ_GPT2 },
-       { .phys_base = 0x48034000, .irq = OMAP44XX_IRQ_GPT3 },
-       { .phys_base = 0x48036000, .irq = OMAP44XX_IRQ_GPT4 },
-       { .phys_base = 0x40138000, .irq = OMAP44XX_IRQ_GPT5 },
-       { .phys_base = 0x4013a000, .irq = OMAP44XX_IRQ_GPT6 },
-       { .phys_base = 0x4013a000, .irq = OMAP44XX_IRQ_GPT7 },
-       { .phys_base = 0x4013e000, .irq = OMAP44XX_IRQ_GPT8 },
-       { .phys_base = 0x4803e000, .irq = OMAP44XX_IRQ_GPT9 },
-       { .phys_base = 0x48086000, .irq = OMAP44XX_IRQ_GPT10 },
-       { .phys_base = 0x48088000, .irq = OMAP44XX_IRQ_GPT11 },
-       { .phys_base = 0x4a320000, .irq = OMAP44XX_IRQ_GPT12 },
-};
-static const char *omap4_dm_source_names[] __initdata = {
-       "sys_clkin_ck",
-       "sys_32k_ck",
-       NULL
-};
-static struct clk *omap4_dm_source_clocks[2];
-static const int omap4_dm_timer_count = ARRAY_SIZE(omap4_dm_timers);
-
-#else
-#define omap4_dm_timers                        NULL
-#define omap4_dm_timer_count           0
-#define omap4_dm_source_names          NULL
-#define omap4_dm_source_clocks         NULL
-#endif /* CONFIG_ARCH_OMAP4 */
-
-static struct omap_dm_timer *dm_timers;
-static const char **dm_source_names;
-static struct clk **dm_source_clocks;
+#include <plat/dmtimer.h>
 
-static spinlock_t dm_timer_lock;
+static LIST_HEAD(omap_timer_list);
+static DEFINE_SPINLOCK(dm_timer_lock);
 
-/*
- * Reads timer registers in posted and non-posted mode. The posted mode bit
- * is encoded in reg. Note that in posted mode write pending bit must be
- * checked. Otherwise a read of a non completed write will produce an error.
+/**
+ * omap_dm_timer_read_reg - read timer registers in posted and non-posted mode
+ * @timer:      timer pointer over which read operation to perform
+ * @reg:        lowest byte holds the register offset
+ *
+ * The posted mode bit is encoded in reg. Note that in posted mode write
+ * pending bit must be checked. Otherwise a read of a non completed write
+ * will produce an error.
  */
 static inline u32 omap_dm_timer_read_reg(struct omap_dm_timer *timer, u32 reg)
 {
-       return __omap_dm_timer_read(timer->io_base, reg, timer->posted);
+       WARN_ON((reg & 0xff) < _OMAP_TIMER_WAKEUP_EN_OFFSET);
+       return __omap_dm_timer_read(timer, reg, timer->posted);
 }
 
-/*
- * Writes timer registers in posted and non-posted mode. The posted mode bit
- * is encoded in reg. Note that in posted mode the write pending bit must be
- * checked. Otherwise a write on a register which has a pending write will be
- * lost.
+/**
+ * omap_dm_timer_write_reg - write timer registers in posted and non-posted mode
+ * @timer:      timer pointer over which write operation is to perform
+ * @reg:        lowest byte holds the register offset
+ * @value:      data to write into the register
+ *
+ * The posted mode bit is encoded in reg. Note that in posted mode the write
+ * pending bit must be checked. Otherwise a write on a register which has a
+ * pending write will be lost.
  */
 static void omap_dm_timer_write_reg(struct omap_dm_timer *timer, u32 reg,
                                                u32 value)
 {
-       __omap_dm_timer_write(timer->io_base, reg, value, timer->posted);
+       WARN_ON((reg & 0xff) < _OMAP_TIMER_WAKEUP_EN_OFFSET);
+       __omap_dm_timer_write(timer, reg, value, timer->posted);
+}
+
+static void omap_timer_restore_context(struct omap_dm_timer *timer)
+{
+       omap_dm_timer_write_reg(timer, OMAP_TIMER_OCP_CFG_OFFSET,
+                               timer->context.tiocp_cfg);
+       if (timer->revision > 1)
+               __raw_writel(timer->context.tistat, timer->sys_stat);
+
+       __raw_writel(timer->context.tisr, timer->irq_stat);
+       omap_dm_timer_write_reg(timer, OMAP_TIMER_WAKEUP_EN_REG,
+                               timer->context.twer);
+       omap_dm_timer_write_reg(timer, OMAP_TIMER_COUNTER_REG,
+                               timer->context.tcrr);
+       omap_dm_timer_write_reg(timer, OMAP_TIMER_LOAD_REG,
+                               timer->context.tldr);
+       omap_dm_timer_write_reg(timer, OMAP_TIMER_MATCH_REG,
+                               timer->context.tmar);
+       omap_dm_timer_write_reg(timer, OMAP_TIMER_IF_CTRL_REG,
+                               timer->context.tsicr);
+       __raw_writel(timer->context.tier, timer->irq_ena);
+       omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG,
+                               timer->context.tclr);
 }
 
 static void omap_dm_timer_wait_for_reset(struct omap_dm_timer *timer)
 {
        int c;
 
+       if (!timer->sys_stat)
+               return;
+
        c = 0;
-       while (!(omap_dm_timer_read_reg(timer, OMAP_TIMER_SYS_STAT_REG) & 1)) {
+       while (!(__raw_readl(timer->sys_stat) & 1)) {
                c++;
                if (c > 100000) {
                        printk(KERN_ERR "Timer failed to reset\n");
@@ -201,53 +119,65 @@ static void omap_dm_timer_wait_for_reset(struct omap_dm_timer *timer)
 
 static void omap_dm_timer_reset(struct omap_dm_timer *timer)
 {
-       int autoidle = 0, wakeup = 0;
-
-       if (!cpu_class_is_omap2() || timer != &dm_timers[0]) {
+       omap_dm_timer_enable(timer);
+       if (timer->pdev->id != 1) {
                omap_dm_timer_write_reg(timer, OMAP_TIMER_IF_CTRL_REG, 0x06);
                omap_dm_timer_wait_for_reset(timer);
        }
-       omap_dm_timer_set_source(timer, OMAP_TIMER_SRC_32_KHZ);
-
-       /* Enable autoidle on OMAP2+ */
-       if (cpu_class_is_omap2())
-               autoidle = 1;
-
-       /*
-        * Enable wake-up on OMAP2 CPUs.
-        */
-       if (cpu_class_is_omap2())
-               wakeup = 1;
 
-       __omap_dm_timer_reset(timer->io_base, autoidle, wakeup);
+       __omap_dm_timer_reset(timer, 0, 0);
+       omap_dm_timer_disable(timer);
        timer->posted = 1;
 }
 
-void omap_dm_timer_prepare(struct omap_dm_timer *timer)
+int omap_dm_timer_prepare(struct omap_dm_timer *timer)
 {
-       omap_dm_timer_enable(timer);
-       omap_dm_timer_reset(timer);
+       struct dmtimer_platform_data *pdata = timer->pdev->dev.platform_data;
+       int ret;
+
+       timer->fclk = clk_get(&timer->pdev->dev, "fck");
+       if (WARN_ON_ONCE(IS_ERR_OR_NULL(timer->fclk))) {
+               timer->fclk = NULL;
+               dev_err(&timer->pdev->dev, ": No fclk handle.\n");
+               return -EINVAL;
+       }
+
+       if (pdata->needs_manual_reset)
+               omap_dm_timer_reset(timer);
+
+       ret = omap_dm_timer_set_source(timer, OMAP_TIMER_SRC_32_KHZ);
+
+       timer->posted = 1;
+       return ret;
 }
 
 struct omap_dm_timer *omap_dm_timer_request(void)
 {
-       struct omap_dm_timer *timer = NULL;
+       struct omap_dm_timer *timer = NULL, *t;
        unsigned long flags;
-       int i;
+       int ret = 0;
 
        spin_lock_irqsave(&dm_timer_lock, flags);
-       for (i = 0; i < dm_timer_count; i++) {
-               if (dm_timers[i].reserved)
+       list_for_each_entry(t, &omap_timer_list, node) {
+               if (t->reserved)
                        continue;
 
-               timer = &dm_timers[i];
+               timer = t;
                timer->reserved = 1;
                break;
        }
+
+       if (timer) {
+               ret = omap_dm_timer_prepare(timer);
+               if (ret) {
+                       timer->reserved = 0;
+                       timer = NULL;
+               }
+       }
        spin_unlock_irqrestore(&dm_timer_lock, flags);
 
-       if (timer != NULL)
-               omap_dm_timer_prepare(timer);
+       if (!timer)
+               pr_debug("%s: timer request failed!\n", __func__);
 
        return timer;
 }
@@ -255,74 +185,65 @@ EXPORT_SYMBOL_GPL(omap_dm_timer_request);
 
 struct omap_dm_timer *omap_dm_timer_request_specific(int id)
 {
-       struct omap_dm_timer *timer;
+       struct omap_dm_timer *timer = NULL, *t;
        unsigned long flags;
+       int ret = 0;
 
        spin_lock_irqsave(&dm_timer_lock, flags);
-       if (id <= 0 || id > dm_timer_count || dm_timers[id-1].reserved) {
-               spin_unlock_irqrestore(&dm_timer_lock, flags);
-               printk("BUG: warning at %s:%d/%s(): unable to get timer %d\n",
-                      __FILE__, __LINE__, __func__, id);
-               dump_stack();
-               return NULL;
+       list_for_each_entry(t, &omap_timer_list, node) {
+               if (t->pdev->id == id && !t->reserved) {
+                       timer = t;
+                       timer->reserved = 1;
+                       break;
+               }
        }
 
-       timer = &dm_timers[id-1];
-       timer->reserved = 1;
+       if (timer) {
+               ret = omap_dm_timer_prepare(timer);
+               if (ret) {
+                       timer->reserved = 0;
+                       timer = NULL;
+               }
+       }
        spin_unlock_irqrestore(&dm_timer_lock, flags);
 
-       omap_dm_timer_prepare(timer);
+       if (!timer)
+               pr_debug("%s: timer%d request failed!\n", __func__, id);
 
        return timer;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_request_specific);
 
-void omap_dm_timer_free(struct omap_dm_timer *timer)
+int omap_dm_timer_free(struct omap_dm_timer *timer)
 {
-       omap_dm_timer_enable(timer);
-       omap_dm_timer_reset(timer);
-       omap_dm_timer_disable(timer);
+       if (unlikely(!timer))
+               return -EINVAL;
+
+       clk_put(timer->fclk);
 
        WARN_ON(!timer->reserved);
        timer->reserved = 0;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_free);
 
 void omap_dm_timer_enable(struct omap_dm_timer *timer)
 {
-       if (timer->enabled)
-               return;
-
-#ifdef CONFIG_ARCH_OMAP2PLUS
-       if (cpu_class_is_omap2()) {
-               clk_enable(timer->fclk);
-               clk_enable(timer->iclk);
-       }
-#endif
-
-       timer->enabled = 1;
+       pm_runtime_get_sync(&timer->pdev->dev);
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_enable);
 
 void omap_dm_timer_disable(struct omap_dm_timer *timer)
 {
-       if (!timer->enabled)
-               return;
-
-#ifdef CONFIG_ARCH_OMAP2PLUS
-       if (cpu_class_is_omap2()) {
-               clk_disable(timer->iclk);
-               clk_disable(timer->fclk);
-       }
-#endif
-
-       timer->enabled = 0;
+       pm_runtime_put(&timer->pdev->dev);
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_disable);
 
 int omap_dm_timer_get_irq(struct omap_dm_timer *timer)
 {
-       return timer->irq;
+       if (timer)
+               return timer->irq;
+       return -EINVAL;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_get_irq);
 
@@ -334,24 +255,29 @@ EXPORT_SYMBOL_GPL(omap_dm_timer_get_irq);
  */
 __u32 omap_dm_timer_modify_idlect_mask(__u32 inputmask)
 {
-       int i;
+       int i = 0;
+       struct omap_dm_timer *timer = NULL;
+       unsigned long flags;
 
        /* If ARMXOR cannot be idled this function call is unnecessary */
        if (!(inputmask & (1 << 1)))
                return inputmask;
 
        /* If any active timer is using ARMXOR return modified mask */
-       for (i = 0; i < dm_timer_count; i++) {
+       spin_lock_irqsave(&dm_timer_lock, flags);
+       list_for_each_entry(timer, &omap_timer_list, node) {
                u32 l;
 
-               l = omap_dm_timer_read_reg(&dm_timers[i], OMAP_TIMER_CTRL_REG);
+               l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
                if (l & OMAP_TIMER_CTRL_ST) {
                        if (((omap_readl(MOD_CONF_CTRL_1) >> (i * 2)) & 0x03) == 0)
                                inputmask &= ~(1 << 1);
                        else
                                inputmask &= ~(1 << 2);
                }
+               i++;
        }
+       spin_unlock_irqrestore(&dm_timer_lock, flags);
 
        return inputmask;
 }
@@ -361,7 +287,9 @@ EXPORT_SYMBOL_GPL(omap_dm_timer_modify_idlect_mask);
 
 struct clk *omap_dm_timer_get_fclk(struct omap_dm_timer *timer)
 {
-       return timer->fclk;
+       if (timer)
+               return timer->fclk;
+       return NULL;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_get_fclk);
 
@@ -375,70 +303,91 @@ EXPORT_SYMBOL_GPL(omap_dm_timer_modify_idlect_mask);
 
 #endif
 
-void omap_dm_timer_trigger(struct omap_dm_timer *timer)
+int omap_dm_timer_trigger(struct omap_dm_timer *timer)
 {
+       if (unlikely(!timer || pm_runtime_suspended(&timer->pdev->dev))) {
+               pr_err("%s: timer not available or enabled.\n", __func__);
+               return -EINVAL;
+       }
+
        omap_dm_timer_write_reg(timer, OMAP_TIMER_TRIGGER_REG, 0);
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_trigger);
 
-void omap_dm_timer_start(struct omap_dm_timer *timer)
+int omap_dm_timer_start(struct omap_dm_timer *timer)
 {
        u32 l;
 
+       if (unlikely(!timer))
+               return -EINVAL;
+
+       omap_dm_timer_enable(timer);
+
+       if (timer->loses_context) {
+               u32 ctx_loss_cnt_after =
+                       timer->get_context_loss_count(&timer->pdev->dev);
+               if (ctx_loss_cnt_after != timer->ctx_loss_count)
+                       omap_timer_restore_context(timer);
+       }
+
        l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
        if (!(l & OMAP_TIMER_CTRL_ST)) {
                l |= OMAP_TIMER_CTRL_ST;
                omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
        }
+
+       /* Save the context */
+       timer->context.tclr = l;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_start);
 
-void omap_dm_timer_stop(struct omap_dm_timer *timer)
+int omap_dm_timer_stop(struct omap_dm_timer *timer)
 {
        unsigned long rate = 0;
+       struct dmtimer_platform_data *pdata = timer->pdev->dev.platform_data;
 
-#ifdef CONFIG_ARCH_OMAP2PLUS
-       rate = clk_get_rate(timer->fclk);
-#endif
+       if (unlikely(!timer))
+               return -EINVAL;
 
-       __omap_dm_timer_stop(timer->io_base, timer->posted, rate);
+       if (!pdata->needs_manual_reset)
+               rate = clk_get_rate(timer->fclk);
+
+       __omap_dm_timer_stop(timer, timer->posted, rate);
+
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_stop);
 
-#ifdef CONFIG_ARCH_OMAP1
-
 int omap_dm_timer_set_source(struct omap_dm_timer *timer, int source)
 {
-       int n = (timer - dm_timers) << 1;
-       u32 l;
-
-       l = omap_readl(MOD_CONF_CTRL_1) & ~(0x03 << n);
-       l |= source << n;
-       omap_writel(l, MOD_CONF_CTRL_1);
+       int ret;
+       struct dmtimer_platform_data *pdata;
 
-       return 0;
-}
-EXPORT_SYMBOL_GPL(omap_dm_timer_set_source);
+       if (unlikely(!timer))
+               return -EINVAL;
 
-#else
+       pdata = timer->pdev->dev.platform_data;
 
-int omap_dm_timer_set_source(struct omap_dm_timer *timer, int source)
-{
        if (source < 0 || source >= 3)
                return -EINVAL;
 
-       return __omap_dm_timer_set_source(timer->fclk,
-                                               dm_source_clocks[source]);
+       ret = pdata->set_timer_src(timer->pdev, source);
+
+       return ret;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_set_source);
 
-#endif
-
-void omap_dm_timer_set_load(struct omap_dm_timer *timer, int autoreload,
+int omap_dm_timer_set_load(struct omap_dm_timer *timer, int autoreload,
                            unsigned int load)
 {
        u32 l;
 
+       if (unlikely(!timer))
+               return -EINVAL;
+
+       omap_dm_timer_enable(timer);
        l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
        if (autoreload)
                l |= OMAP_TIMER_CTRL_AR;
@@ -448,15 +397,32 @@ void omap_dm_timer_set_load(struct omap_dm_timer *timer, int autoreload,
        omap_dm_timer_write_reg(timer, OMAP_TIMER_LOAD_REG, load);
 
        omap_dm_timer_write_reg(timer, OMAP_TIMER_TRIGGER_REG, 0);
+       /* Save the context */
+       timer->context.tclr = l;
+       timer->context.tldr = load;
+       omap_dm_timer_disable(timer);
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_set_load);
 
 /* Optimized set_load which removes costly spin wait in timer_start */
-void omap_dm_timer_set_load_start(struct omap_dm_timer *timer, int autoreload,
+int omap_dm_timer_set_load_start(struct omap_dm_timer *timer, int autoreload,
                             unsigned int load)
 {
        u32 l;
 
+       if (unlikely(!timer))
+               return -EINVAL;
+
+       omap_dm_timer_enable(timer);
+
+       if (timer->loses_context) {
+               u32 ctx_loss_cnt_after =
+                       timer->get_context_loss_count(&timer->pdev->dev);
+               if (ctx_loss_cnt_after != timer->ctx_loss_count)
+                       omap_timer_restore_context(timer);
+       }
+
        l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
        if (autoreload) {
                l |= OMAP_TIMER_CTRL_AR;
@@ -466,15 +432,25 @@ void omap_dm_timer_set_load_start(struct omap_dm_timer *timer, int autoreload,
        }
        l |= OMAP_TIMER_CTRL_ST;
 
-       __omap_dm_timer_load_start(timer->io_base, l, load, timer->posted);
+       __omap_dm_timer_load_start(timer, l, load, timer->posted);
+
+       /* Save the context */
+       timer->context.tclr = l;
+       timer->context.tldr = load;
+       timer->context.tcrr = load;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_set_load_start);
 
-void omap_dm_timer_set_match(struct omap_dm_timer *timer, int enable,
+int omap_dm_timer_set_match(struct omap_dm_timer *timer, int enable,
                             unsigned int match)
 {
        u32 l;
 
+       if (unlikely(!timer))
+               return -EINVAL;
+
+       omap_dm_timer_enable(timer);
        l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
        if (enable)
                l |= OMAP_TIMER_CTRL_CE;
@@ -482,14 +458,24 @@ void omap_dm_timer_set_match(struct omap_dm_timer *timer, int enable,
                l &= ~OMAP_TIMER_CTRL_CE;
        omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
        omap_dm_timer_write_reg(timer, OMAP_TIMER_MATCH_REG, match);
+
+       /* Save the context */
+       timer->context.tclr = l;
+       timer->context.tmar = match;
+       omap_dm_timer_disable(timer);
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_set_match);
 
-void omap_dm_timer_set_pwm(struct omap_dm_timer *timer, int def_on,
+int omap_dm_timer_set_pwm(struct omap_dm_timer *timer, int def_on,
                           int toggle, int trigger)
 {
        u32 l;
 
+       if (unlikely(!timer))
+               return -EINVAL;
+
+       omap_dm_timer_enable(timer);
        l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
        l &= ~(OMAP_TIMER_CTRL_GPOCFG | OMAP_TIMER_CTRL_SCPWM |
               OMAP_TIMER_CTRL_PT | (0x03 << 10));
@@ -499,13 +485,22 @@ void omap_dm_timer_set_pwm(struct omap_dm_timer *timer, int def_on,
                l |= OMAP_TIMER_CTRL_PT;
        l |= trigger << 10;
        omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
+
+       /* Save the context */
+       timer->context.tclr = l;
+       omap_dm_timer_disable(timer);
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_set_pwm);
 
-void omap_dm_timer_set_prescaler(struct omap_dm_timer *timer, int prescaler)
+int omap_dm_timer_set_prescaler(struct omap_dm_timer *timer, int prescaler)
 {
        u32 l;
 
+       if (unlikely(!timer))
+               return -EINVAL;
+
+       omap_dm_timer_enable(timer);
        l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG);
        l &= ~(OMAP_TIMER_CTRL_PRE | (0x07 << 2));
        if (prescaler >= 0x00 && prescaler <= 0x07) {
@@ -513,13 +508,28 @@ void omap_dm_timer_set_prescaler(struct omap_dm_timer *timer, int prescaler)
                l |= prescaler << 2;
        }
        omap_dm_timer_write_reg(timer, OMAP_TIMER_CTRL_REG, l);
+
+       /* Save the context */
+       timer->context.tclr = l;
+       omap_dm_timer_disable(timer);
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_set_prescaler);
 
-void omap_dm_timer_set_int_enable(struct omap_dm_timer *timer,
+int omap_dm_timer_set_int_enable(struct omap_dm_timer *timer,
                                  unsigned int value)
 {
-       __omap_dm_timer_int_enable(timer->io_base, value);
+       if (unlikely(!timer))
+               return -EINVAL;
+
+       omap_dm_timer_enable(timer);
+       __omap_dm_timer_int_enable(timer, value);
+
+       /* Save the context */
+       timer->context.tier = value;
+       timer->context.twer = value;
+       omap_dm_timer_disable(timer);
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_set_int_enable);
 
@@ -527,40 +537,61 @@ unsigned int omap_dm_timer_read_status(struct omap_dm_timer *timer)
 {
        unsigned int l;
 
-       l = omap_dm_timer_read_reg(timer, OMAP_TIMER_STAT_REG);
+       if (unlikely(!timer || pm_runtime_suspended(&timer->pdev->dev))) {
+               pr_err("%s: timer not available or enabled.\n", __func__);
+               return 0;
+       }
+
+       l = __raw_readl(timer->irq_stat);
 
        return l;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_read_status);
 
-void omap_dm_timer_write_status(struct omap_dm_timer *timer, unsigned int value)
+int omap_dm_timer_write_status(struct omap_dm_timer *timer, unsigned int value)
 {
-       __omap_dm_timer_write_status(timer->io_base, value);
+       if (unlikely(!timer || pm_runtime_suspended(&timer->pdev->dev)))
+               return -EINVAL;
+
+       __omap_dm_timer_write_status(timer, value);
+       /* Save the context */
+       timer->context.tisr = value;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_write_status);
 
 unsigned int omap_dm_timer_read_counter(struct omap_dm_timer *timer)
 {
-       return __omap_dm_timer_read_counter(timer->io_base, timer->posted);
+       if (unlikely(!timer || pm_runtime_suspended(&timer->pdev->dev))) {
+               pr_err("%s: timer not iavailable or enabled.\n", __func__);
+               return 0;
+       }
+
+       return __omap_dm_timer_read_counter(timer, timer->posted);
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_read_counter);
 
-void omap_dm_timer_write_counter(struct omap_dm_timer *timer, unsigned int value)
+int omap_dm_timer_write_counter(struct omap_dm_timer *timer, unsigned int value)
 {
+       if (unlikely(!timer || pm_runtime_suspended(&timer->pdev->dev))) {
+               pr_err("%s: timer not available or enabled.\n", __func__);
+               return -EINVAL;
+       }
+
        omap_dm_timer_write_reg(timer, OMAP_TIMER_COUNTER_REG, value);
+
+       /* Save the context */
+       timer->context.tcrr = value;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(omap_dm_timer_write_counter);
 
 int omap_dm_timers_active(void)
 {
-       int i;
-
-       for (i = 0; i < dm_timer_count; i++) {
-               struct omap_dm_timer *timer;
-
-               timer = &dm_timers[i];
+       struct omap_dm_timer *timer;
 
-               if (!timer->enabled)
+       list_for_each_entry(timer, &omap_timer_list, node) {
+               if (!timer->reserved)
                        continue;
 
                if (omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG) &
@@ -572,69 +603,147 @@ int omap_dm_timers_active(void)
 }
 EXPORT_SYMBOL_GPL(omap_dm_timers_active);
 
-static int __init omap_dm_timer_init(void)
+/**
+ * omap_dm_timer_probe - probe function called for every registered device
+ * @pdev:      pointer to current timer platform device
+ *
+ * Called by driver framework at the end of device registration for all
+ * timer devices.
+ */
+static int __devinit omap_dm_timer_probe(struct platform_device *pdev)
 {
+       int ret;
+       unsigned long flags;
        struct omap_dm_timer *timer;
-       int i, map_size = SZ_8K;        /* Module 4KB + L4 4KB except on omap1 */
+       struct resource *mem, *irq, *ioarea;
+       struct dmtimer_platform_data *pdata = pdev->dev.platform_data;
 
-       if (!(cpu_is_omap16xx() || cpu_class_is_omap2()))
+       if (!pdata) {
+               dev_err(&pdev->dev, "%s: no platform data.\n", __func__);
                return -ENODEV;
+       }
 
-       spin_lock_init(&dm_timer_lock);
-
-       if (cpu_class_is_omap1()) {
-               dm_timers = omap1_dm_timers;
-               dm_timer_count = omap1_dm_timer_count;
-               map_size = SZ_2K;
-       } else if (cpu_is_omap24xx()) {
-               dm_timers = omap2_dm_timers;
-               dm_timer_count = omap2_dm_timer_count;
-               dm_source_names = omap2_dm_source_names;
-               dm_source_clocks = omap2_dm_source_clocks;
-       } else if (cpu_is_omap34xx()) {
-               dm_timers = omap3_dm_timers;
-               dm_timer_count = omap3_dm_timer_count;
-               dm_source_names = omap3_dm_source_names;
-               dm_source_clocks = omap3_dm_source_clocks;
-       } else if (cpu_is_omap44xx()) {
-               dm_timers = omap4_dm_timers;
-               dm_timer_count = omap4_dm_timer_count;
-               dm_source_names = omap4_dm_source_names;
-               dm_source_clocks = omap4_dm_source_clocks;
+       irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+       if (unlikely(!irq)) {
+               dev_err(&pdev->dev, "%s: no IRQ resource.\n", __func__);
+               return -ENODEV;
        }
 
-       if (cpu_class_is_omap2())
-               for (i = 0; dm_source_names[i] != NULL; i++)
-                       dm_source_clocks[i] = clk_get(NULL, dm_source_names[i]);
+       mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (unlikely(!mem)) {
+               dev_err(&pdev->dev, "%s: no memory resource.\n", __func__);
+               return -ENODEV;
+       }
 
-       if (cpu_is_omap243x())
-               dm_timers[0].phys_base = 0x49018000;
+       ioarea = request_mem_region(mem->start, resource_size(mem),
+                       pdev->name);
+       if (!ioarea) {
+               dev_err(&pdev->dev, "%s: region already claimed.\n", __func__);
+               return -EBUSY;
+       }
 
-       for (i = 0; i < dm_timer_count; i++) {
-               timer = &dm_timers[i];
+       timer = kzalloc(sizeof(struct omap_dm_timer), GFP_KERNEL);
+       if (!timer) {
+               dev_err(&pdev->dev, "%s: no memory for omap_dm_timer.\n",
+                       __func__);
+               ret = -ENOMEM;
+               goto err_free_ioregion;
+       }
 
-               /* Static mapping, never released */
-               timer->io_base = ioremap(timer->phys_base, map_size);
-               BUG_ON(!timer->io_base);
+       timer->io_base = ioremap(mem->start, resource_size(mem));
+       if (!timer->io_base) {
+               dev_err(&pdev->dev, "%s: ioremap failed.\n", __func__);
+               ret = -ENOMEM;
+               goto err_free_mem;
+       }
 
-#ifdef CONFIG_ARCH_OMAP2PLUS
-               if (cpu_class_is_omap2()) {
-                       char clk_name[16];
-                       sprintf(clk_name, "gpt%d_ick", i + 1);
-                       timer->iclk = clk_get(NULL, clk_name);
-                       sprintf(clk_name, "gpt%d_fck", i + 1);
-                       timer->fclk = clk_get(NULL, clk_name);
-               }
+       timer->id = pdev->id;
+       timer->irq = irq->start;
+       timer->reserved = pdata->reserved;
+       timer->pdev = pdev;
+       timer->loses_context = pdata->loses_context;
+       timer->get_context_loss_count = pdata->get_context_loss_count;
+
+       /* Skip pm_runtime_enable for OMAP1 */
+       if (!pdata->needs_manual_reset) {
+               pm_runtime_enable(&pdev->dev);
+               pm_runtime_irq_safe(&pdev->dev);
+       }
 
-               /* One or two timers may be set up early for sys_timer */
-               if (sys_timer_reserved & (1  << i)) {
-                       timer->reserved = 1;
-                       timer->posted = 1;
-               }
-#endif
+       if (!timer->reserved) {
+               pm_runtime_get_sync(&pdev->dev);
+               __omap_dm_timer_init_regs(timer);
+               pm_runtime_put(&pdev->dev);
        }
 
+       /* add the timer element to the list */
+       spin_lock_irqsave(&dm_timer_lock, flags);
+       list_add_tail(&timer->node, &omap_timer_list);
+       spin_unlock_irqrestore(&dm_timer_lock, flags);
+
+       dev_dbg(&pdev->dev, "Device Probed.\n");
+
        return 0;
+
+err_free_mem:
+       kfree(timer);
+
+err_free_ioregion:
+       release_mem_region(mem->start, resource_size(mem));
+
+       return ret;
 }
 
-arch_initcall(omap_dm_timer_init);
+/**
+ * omap_dm_timer_remove - cleanup a registered timer device
+ * @pdev:      pointer to current timer platform device
+ *
+ * Called by driver framework whenever a timer device is unregistered.
+ * In addition to freeing platform resources it also deletes the timer
+ * entry from the local list.
+ */
+static int __devexit omap_dm_timer_remove(struct platform_device *pdev)
+{
+       struct omap_dm_timer *timer;
+       unsigned long flags;
+       int ret = -EINVAL;
+
+       spin_lock_irqsave(&dm_timer_lock, flags);
+       list_for_each_entry(timer, &omap_timer_list, node)
+               if (timer->pdev->id == pdev->id) {
+                       list_del(&timer->node);
+                       kfree(timer);
+                       ret = 0;
+                       break;
+               }
+       spin_unlock_irqrestore(&dm_timer_lock, flags);
+
+       return ret;
+}
+
+static struct platform_driver omap_dm_timer_driver = {
+       .probe  = omap_dm_timer_probe,
+       .remove = __devexit_p(omap_dm_timer_remove),
+       .driver = {
+               .name   = "omap_timer",
+       },
+};
+
+static int __init omap_dm_timer_driver_init(void)
+{
+       return platform_driver_register(&omap_dm_timer_driver);
+}
+
+static void __exit omap_dm_timer_driver_exit(void)
+{
+       platform_driver_unregister(&omap_dm_timer_driver);
+}
+
+early_platform_init("earlytimer", &omap_dm_timer_driver);
+module_init(omap_dm_timer_driver_init);
+module_exit(omap_dm_timer_driver_exit);
+
+MODULE_DESCRIPTION("OMAP Dual-Mode Timer Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_AUTHOR("Texas Instruments Inc");