Document DT bindings and parse them in the CMT driver.
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Tested-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
---
.../devicetree/bindings/timer/renesas,cmt.txt | 47 +++++++++++++++
drivers/clocksource/sh_cmt.c | 66 ++++++++++++++++------
2 files changed, 95 insertions(+), 18 deletions(-)
create mode 100644 Documentation/devicetree/bindings/timer/renesas,cmt.txt
diff --git a/Documentation/devicetree/bindings/timer/renesas,cmt.txt b/Documentation/devicetree/bindings/timer/renesas,cmt.txt
new file mode 100644
index 0000000..643cfff
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/renesas,cmt.txt
@@ -0,0 +1,47 @@
+* Renesas R-Car Compare Match Timer (CMT)
+
+The CMT is a multi-channel 16/32/48-bit timer/counter with configurable clock
+inputs and programmable compare match.
+
+Channels share hardware resources but their counter and compare match value
+are independent. A particular CMT instance can implement only a subset of the
+channels supported by the CMT model. Channel indices represent the hardware
+position of the channel in the CMT and don't match the channel numbers in the
+datasheets.
+
+Required Properties:
+
+ - compatible: must contain one of the following.
+ - "renesas,cmt-32" for the 32-bit CMT
+ (CMT0 on sh7372, sh73a0 and r8a7740)
+ - "renesas,cmt-32-fast" for the 32-bit CMT with fast clock support
+ (CMT[234] on sh7372, sh73a0 and r8a7740)
+ - "renasas,cmt-48" for the 48-bit CMT
+ (CMT1 on sh7372, sh73a0 and r8a7740)
+ - "renesas,cmt-48-gen2" for the second generation 48-bit CMT
+ (CMT[01] on r8a73a4, r8a7790 and r8a7791)
+
+ - reg: base address and length of the registers block for the timer module.
+ - interrupts: interrupt-specifier for the timer, one per channel.
+ - clocks: a list of phandle + clock-specifier pairs, one for each entry
+ in clock-names.
+ - clock-names: must contain "fck" for the functional clock.
+
+ - renesas,channels-mask: bitmask of the available channels.
+
+
+Example: R8A7790 (R-Car H2) CMT0 node
+
+ CMT0 on R8A7790 implements hardware channels 5 and 6 only and names
+ them channels 0 and 1 in the documentation.
+
+ cmt0: timer@ffca0000 {
+ compatible = "renesas,cmt-48-gen2";
+ reg = <0 0xffca0000 0 0x1004>;
+ interrupts = <0 142 IRQ_TYPE_LEVEL_HIGH>,
+ <0 142 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&mstp1_clks R8A7790_CLK_CMT0>;
+ clock-names = "fck";
+
+ renesas,channels-mask = <0x60>;
+ };
diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index 4d00e4b..09a93c4 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 = "renasas,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;
@@ -1044,21 +1083,12 @@ 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,
};
--
1.8.5.5
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