clocksource: sh_cmt: Add DT support

Document DT bindings and parse them in the CMT driver.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Simon Horman <horms+renesas@verge.net.au>

1 files changed, 48 insertions, 18 deletions

diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index 190c655d8352..2bd13b53b727 100644
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -24,6 +24,7 @@
 #include <linux/ioport.h>
 #include <linux/irq.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
@@ -122,6 +123,7 @@ struct sh_cmt_device {
 
         struct sh_cmt_channel *channels;
         unsigned int num_channels;
+        unsigned int hw_channels;
 
         bool has_clockevent;
         bool has_clocksource;
@@ -924,10 +926,35 @@ static int sh_cmt_map_memory(struct sh_cmt_device *cmt)
         return 0;
 }
 
+static const struct platform_device_id sh_cmt_id_table[] = {
+        { "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] },
+        { "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] },
+        { "sh-cmt-32-fast", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT_FAST] },
+        { "sh-cmt-48", (kernel_ulong_t)&sh_cmt_info[SH_CMT_48BIT] },
+        { "sh-cmt-48-gen2", (kernel_ulong_t)&sh_cmt_info[SH_CMT_48BIT_GEN2] },
+        { }
+};
+MODULE_DEVICE_TABLE(platform, sh_cmt_id_table);
+
+static const struct of_device_id sh_cmt_of_table[] __maybe_unused = {
+        { .compatible = "renesas,cmt-32", .data = &sh_cmt_info[SH_CMT_32BIT] },
+        { .compatible = "renesas,cmt-32-fast", .data = &sh_cmt_info[SH_CMT_32BIT_FAST] },
+        { .compatible = "renesas,cmt-48", .data = &sh_cmt_info[SH_CMT_48BIT] },
+        { .compatible = "renesas,cmt-48-gen2", .data = &sh_cmt_info[SH_CMT_48BIT_GEN2] },
+        { }
+};
+MODULE_DEVICE_TABLE(of, sh_cmt_of_table);
+
+static int sh_cmt_parse_dt(struct sh_cmt_device *cmt)
+{
+        struct device_node *np = cmt->pdev->dev.of_node;
+
+        return of_property_read_u32(np, "renesas,channels-mask",
+                                    &cmt->hw_channels);
+}
+
 static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
 {
-        struct sh_timer_config *cfg = pdev->dev.platform_data;
-        const struct platform_device_id *id = pdev->id_entry;
         unsigned int mask;
         unsigned int i;
         int ret;
@@ -936,13 +963,26 @@ static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
         cmt->pdev = pdev;
         raw_spin_lock_init(&cmt->lock);
 
-        if (!cfg) {
+        if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) {
+                const struct of_device_id *id;
+
+                id = of_match_node(sh_cmt_of_table, pdev->dev.of_node);
+                cmt->info = id->data;
+
+                ret = sh_cmt_parse_dt(cmt);
+                if (ret < 0)
+                        return ret;
+        } else if (pdev->dev.platform_data) {
+                struct sh_timer_config *cfg = pdev->dev.platform_data;
+                const struct platform_device_id *id = pdev->id_entry;
+
+                cmt->info = (const struct sh_cmt_info *)id->driver_data;
+                cmt->hw_channels = cfg->channels_mask;
+        } else {
                 dev_err(&cmt->pdev->dev, "missing platform data\n");
                 return -ENXIO;
         }
 
-        cmt->info = (const struct sh_cmt_info *)id->driver_data;
-
         /* Get hold of clock. */
         cmt->clk = clk_get(&cmt->pdev->dev, "fck");
         if (IS_ERR(cmt->clk)) {
@@ -960,8 +1000,7 @@ static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
                 goto err_clk_unprepare;
 
         /* Allocate and setup the channels. */
-        cmt->num_channels = hweight8(cfg->channels_mask);
-
+        cmt->num_channels = hweight8(cmt->hw_channels);
         cmt->channels = kzalloc(cmt->num_channels * sizeof(*cmt->channels),
                                 GFP_KERNEL);
         if (cmt->channels == NULL) {
@@ -973,7 +1012,7 @@ static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)
          * Use the first channel as a clock event device and the second channel
          * as a clock source. If only one channel is available use it for both.
          */
-        for (i = 0, mask = cfg->channels_mask; i < cmt->num_channels; ++i) {
+        for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) {
                 unsigned int hwidx = ffs(mask) - 1;
                 bool clocksource = i == 1 || cmt->num_channels == 1;
                 bool clockevent = i == 0;
@@ -1042,21 +1081,12 @@ static int sh_cmt_remove(struct platform_device *pdev)
         return -EBUSY; /* cannot unregister clockevent and clocksource */
 }
 
-static const struct platform_device_id sh_cmt_id_table[] = {
-        { "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] },
-        { "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] },
-        { "sh-cmt-32-fast", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT_FAST] },
-        { "sh-cmt-48", (kernel_ulong_t)&sh_cmt_info[SH_CMT_48BIT] },
-        { "sh-cmt-48-gen2", (kernel_ulong_t)&sh_cmt_info[SH_CMT_48BIT_GEN2] },
-        { }
-};
-MODULE_DEVICE_TABLE(platform, sh_cmt_id_table);
-
 static struct platform_driver sh_cmt_device_driver = {
         .probe          = sh_cmt_probe,
         .remove         = sh_cmt_remove,
         .driver         = {
                 .name   = "sh_cmt",
+                .of_match_table = of_match_ptr(sh_cmt_of_table),
         },
         .id_table       = sh_cmt_id_table,
 };