[PATCH 2/2] clk: bcm2835: Add PWM clock support

Remi Pommarel
2015-11-04T23:08:22Z

Register the pwm clock for bcm2835.
This patch also adds the ability to set a clock default rate.

Signed-off-by: Remi Pommarel <repk@triplefau.lt>
---
arch/arm/boot/dts/bcm2835.dtsi | 8 ++++++++
drivers/clk/bcm/clk-bcm2835.c | 28 +++++++++++++++++++++++++++-
include/dt-bindings/clock/bcm2835.h | 3 ++-
3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/bcm2835.dtsi b/arch/arm/boot/dts/bcm2835.dtsi
index aef64de..0736de3 100644
--- a/arch/arm/boot/dts/bcm2835.dtsi
+++ b/arch/arm/boot/dts/bcm2835.dtsi
@@ -177,6 +177,14 @@
status = "disabled";
};

+ pwm: pwm@7e20c000 {
+ compatible = "brcm,bcm2835-pwm";
+ reg = <0x7e20c000 0x28>;
+ clocks = <&clocks BCM2835_CLOCK_PWM>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
usb@7e980000 {
compatible = "brcm,bcm2835-usb";
reg = <0x7e980000 0x10000>;
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 9469729..0647118 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -39,6 +39,7 @@

#include <linux/clk-provider.h>
#include <linux/clkdev.h>
+#include <linux/clk.h>
#include <linux/clk/bcm2835.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -625,6 +626,8 @@ struct bcm2835_clock_data {
const char *const *parents;
int num_mux_parents;

+ unsigned long dft_rate;
+
u32 ctl_reg;
u32 div_reg;

@@ -807,6 +810,17 @@ static const struct bcm2835_clock_data bcm2835_clock_emmc_data = {
.frac_bits = 8,
};

+static const struct bcm2835_clock_data bcm2835_clock_pwm_data = {
+ .name = "pwm",
+ .num_mux_parents = ARRAY_SIZE(bcm2835_clock_per_parents),
+ .parents = bcm2835_clock_per_parents,
+ .dft_rate = 9600000,
+ .ctl_reg = CM_PWMCTL,
+ .div_reg = CM_PWMDIV,
+ .int_bits = 12,
+ .frac_bits = 12,
+};
+
struct bcm2835_pll {
struct clk_hw hw;
struct bcm2835_cprman *cprman;
@@ -1440,6 +1454,7 @@ bcm2835_register_pll_divider(struct bcm2835_cprman *cprman,
static struct clk *bcm2835_register_clock(struct bcm2835_cprman *cprman,
const struct bcm2835_clock_data *data)
{
+ struct clk *ret;
struct bcm2835_clock *clock;
struct clk_init_data init;
const char *parents[1 << CM_SRC_BITS];
@@ -1477,7 +1492,15 @@ static struct clk *bcm2835_register_clock(struct bcm2835_cprman *cprman,
clock->data = data;
clock->hw.init = &init;

- return devm_clk_register(cprman->dev, &clock->hw);
+ ret = devm_clk_register(cprman->dev, &clock->hw);
+ if (IS_ERR(ret))
+ goto out;
+
+ if (data->dft_rate)
+ clk_set_rate(ret, data->dft_rate);
+
+out:
+ return ret;
}

static int bcm2835_clk_probe(struct platform_device *pdev)
@@ -1576,6 +1599,9 @@ static int bcm2835_clk_probe(struct platform_device *pdev)
cprman->regs + CM_PERIICTL, CM_GATE_BIT,
0, &cprman->regs_lock);

+ clks[BCM2835_CLOCK_PWM] =
+ bcm2835_register_clock(cprman, &bcm2835_clock_pwm_data);
+
return of_clk_add_provider(dev->of_node, of_clk_src_onecell_get,
&cprman->onecell);
}
diff --git a/include/dt-bindings/clock/bcm2835.h b/include/dt-bindings/clock/bcm2835.h
index d323efa..61f1d20 100644
--- a/include/dt-bindings/clock/bcm2835.h
+++ b/include/dt-bindings/clock/bcm2835.h
@@ -43,5 +43,6 @@
#define BCM2835_CLOCK_TSENS 27
#define BCM2835_CLOCK_EMMC 28
#define BCM2835_CLOCK_PERI_IMAGE 29
+#define BCM2835_CLOCK_PWM 30

-#define BCM2835_CLOCK_COUNT 30
+#define BCM2835_CLOCK_COUNT 31
--
2.0.1