clocksource: sh_cmt: Add OF support

We add the capabilty to probe SH CMT timer devices using Device Tree
setup.

Signed-off-by: Bastian Hecht <hechtb+renesas@gmail.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index 08d0c418c94ae5ed3e4c5791ab929fc6501d0de3..66a12e9e0bb49a371f3f1b528d50e3f375519984 100644 (file)
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -34,10 +34,13 @@
 #include <linux/module.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
+#include <linux/of.h>
 
 struct sh_cmt_priv {
        void __iomem *mapbase;
        struct clk *clk;
+       long channel_offset;
+       int timer_bit;
        unsigned long width; /* 16 or 32 bit version of hardware block */
        unsigned long overflow_bit;
        unsigned long clear_bits;
@@ -109,9 +112,7 @@ static void sh_cmt_write32(void __iomem *base, unsigned long offs,
 
 static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_priv *p)
 {
-       struct sh_timer_config *cfg = p->pdev->dev.platform_data;
-
-       return p->read_control(p->mapbase - cfg->channel_offset, 0);
+       return p->read_control(p->mapbase - p->channel_offset, 0);
 }
 
 static inline unsigned long sh_cmt_read_cmcsr(struct sh_cmt_priv *p)
@@ -127,9 +128,7 @@ static inline unsigned long sh_cmt_read_cmcnt(struct sh_cmt_priv *p)
 static inline void sh_cmt_write_cmstr(struct sh_cmt_priv *p,
                                      unsigned long value)
 {
-       struct sh_timer_config *cfg = p->pdev->dev.platform_data;
-
-       p->write_control(p->mapbase - cfg->channel_offset, 0, value);
+       p->write_control(p->mapbase - p->channel_offset, 0, value);
 }
 
 static inline void sh_cmt_write_cmcsr(struct sh_cmt_priv *p,
@@ -176,7 +175,6 @@ static DEFINE_RAW_SPINLOCK(sh_cmt_lock);
 
 static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
 {
-       struct sh_timer_config *cfg = p->pdev->dev.platform_data;
        unsigned long flags, value;
 
        /* start stop register shared by multiple timer channels */
@@ -184,9 +182,9 @@ static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
        value = sh_cmt_read_cmstr(p);
 
        if (start)
-               value |= 1 << cfg->timer_bit;
+               value |= 1 << p->timer_bit;
        else
-               value &= ~(1 << cfg->timer_bit);
+               value &= ~(1 << p->timer_bit);
 
        sh_cmt_write_cmstr(p, value);
        raw_spin_unlock_irqrestore(&sh_cmt_lock, flags);
@@ -673,15 +671,93 @@ static int sh_cmt_register(struct sh_cmt_priv *p, char *name,
        return 0;
 }
 
-static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev)
+static const struct of_device_id of_sh_cmt_match[] = {
+       { .compatible = "renesas,cmt-timer" },
+       {},
+};
+MODULE_DEVICE_TABLE(of, of_sh_cmt_match);
+
+static const int sh_cmt_offset_multiplier[] = { 0x60, 0x10, 0x40, 0x40, 0x40 };
+#define CMT_MAX_CHANNELS       6
+
+static struct sh_timer_config *sh_cmt_parse_dt(struct device *dev)
+{
+       struct sh_timer_config *cfg;
+       struct device_node *np = dev->of_node;
+       u32 timer_id, channel_id, rating;
+
+       if (!IS_ENABLED(CONFIG_OF) || !np)
+               return NULL;
+
+       cfg = devm_kzalloc(dev, sizeof(struct sh_timer_config), GFP_KERNEL);
+       if (!cfg) {
+               dev_err(dev, "failed to allocate DT config data\n");
+               return NULL;
+       }
+
+       if (of_property_read_u32(np, "renesas,device-id", &timer_id)) {
+               dev_err(dev, "device id missing\n");
+               return NULL;
+       }
+       if (timer_id >= ARRAY_SIZE(sh_cmt_offset_multiplier)) {
+               dev_err(dev, "invalid device id\n");
+               return NULL;
+       }
+
+       if (of_property_read_u32(np, "renesas,channel-id", &channel_id)) {
+               dev_err(dev, "channel id missing\n");
+               return NULL;
+       }
+       if (channel_id >= CMT_MAX_CHANNELS) {
+               dev_err(dev, "invalid channel id\n");
+               return NULL;
+       }
+
+       cfg->channel_offset = sh_cmt_offset_multiplier[timer_id] *
+                                                       (channel_id + 1);
+       cfg->timer_bit = channel_id;
+
+       /*
+        * We convert the {source,event}-quality DT properties to linux specific
+        * clock{source,event}_ratings.
+        */
+       if (!of_property_read_u32(np, "renesas,source-quality", &rating)) {
+               if (rating > 10) {
+                       dev_err(dev, "invalid source-quality\n");
+                       return NULL;
+               }
+               if (rating)
+                       cfg->clocksource_rating = rating * 50 - 1;
+       }
+
+       if (!of_property_read_u32(np, "renesas,event-quality", &rating)) {
+               if (rating > 10) {
+                       dev_err(dev, "invalid event-quality\n");
+                       return NULL;
+               }
+               if (rating)
+                       cfg->clockevent_rating = rating * 50 - 1;
+       }
+
+       if (!cfg->clocksource_rating && !cfg->clockevent_rating) {
+               dev_err(dev, "source- and event-quality 0, timer is unused\n");
+               return NULL;
+       }
+
+       return cfg;
+}
+
+static int sh_cmt_setup(struct sh_cmt_priv *p, struct platform_device *pdev,
+                                               struct sh_timer_config *cfg)
 {
-       struct sh_timer_config *cfg = pdev->dev.platform_data;
        struct resource *res;
        int irq, ret;
        ret = -ENXIO;
 
        memset(p, 0, sizeof(*p));
        p->pdev = pdev;
+       p->channel_offset = cfg->channel_offset;
+       p->timer_bit = cfg->timer_bit;
 
        if (!cfg) {
                dev_err(&p->pdev->dev, "missing platform data\n");
@@ -777,7 +853,7 @@ err0:
 static int sh_cmt_probe(struct platform_device *pdev)
 {
        struct sh_cmt_priv *p = platform_get_drvdata(pdev);
-       struct sh_timer_config *cfg = pdev->dev.platform_data;
+       struct sh_timer_config *cfg;
        int ret;
 
        if (!is_early_platform_device(pdev)) {
@@ -785,6 +861,11 @@ static int sh_cmt_probe(struct platform_device *pdev)
                pm_runtime_enable(&pdev->dev);
        }
 
+       if (pdev->dev.of_node)
+               cfg = sh_cmt_parse_dt(&pdev->dev);
+       else
+               cfg = pdev->dev.platform_data;
+
        if (p) {
                dev_info(&pdev->dev, "kept as earlytimer\n");
                goto out;
@@ -796,7 +877,7 @@ static int sh_cmt_probe(struct platform_device *pdev)
                return -ENOMEM;
        }
 
-       ret = sh_cmt_setup(p, pdev);
+       ret = sh_cmt_setup(p, pdev, cfg);
        if (ret) {
                kfree(p);
                pm_runtime_idle(&pdev->dev);
@@ -824,6 +905,7 @@ static struct platform_driver sh_cmt_device_driver = {
        .remove         = sh_cmt_remove,
        .driver         = {
                .name   = "sh_cmt",
+               .of_match_table = of_match_ptr(of_sh_cmt_match),
        }
 };