[PATCH v4 09/19] clocksource: sh_cmt: Add DT support
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Fri Jul 4 06:15:37 PDT 2014
On Monday 16 June 2014 17:07:21 Laurent Pinchart wrote:
> Document DT bindings and parse them in the CMT driver.
>
> Cc: devicetree at vger.kernel.org
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
> Tested-by: Simon Horman <horms+renesas at verge.net.au>
> ---
> .../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
Simon has spotted a nasty typo here and below in the OF match table. I'll fix
that and resubmit the pull request.
> + (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 at 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,
> };
--
Regards,
Laurent Pinchart
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