Re: [PATCH] rtc: sun6i: Add support for the external oscillator gate

From: Alexandre Belloni
Date: Thu Aug 24 2017 - 10:36:52 EST


Hi,

On 24/08/2017 at 14:18:54 +0200, Maxime Ripard wrote:
> The RTC can output its 32kHz clock outside of the SoC, for example to clock
> a WiFi chip.
>
> Create a new clock that other devices will be able to retrieve, while
> maintaining the DT stability by providing a default name for that clock if
> clock-output-names doesn't list one.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/rtc/sun6i-rtc.txt | 4 ++--
> drivers/rtc/rtc-sun6i.c | 24 +++++++++++++++++++---
> 2 files changed, 23 insertions(+), 5 deletions(-)
>

It doesn't apply cleanly, can you rebase on top of -next?

> diff --git a/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt b/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt
> index 945934918b71..d5e26d313f62 100644
> --- a/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt
> +++ b/Documentation/devicetree/bindings/rtc/sun6i-rtc.txt
> @@ -10,7 +10,7 @@ Required properties:
>
> Required properties for new device trees
> - clocks : phandle to the 32kHz external oscillator
> -- clock-output-names : name of the LOSC clock created
> +- clock-output-names : names of the LOSC and its external output clocks created
> - #clock-cells : must be equals to 1. The RTC provides two clocks: the
> LOSC and its external output, with index 0 and 1
> respectively.
> @@ -21,7 +21,7 @@ rtc: rtc@01f00000 {
> compatible = "allwinner,sun6i-a31-rtc";
> reg = <0x01f00000 0x54>;
> interrupts = <0 40 4>, <0 41 4>;
> - clock-output-names = "osc32k";
> + clock-output-names = "osc32k", "osc32k-out";
> clocks = <&ext_osc32k>;
> #clock-cells = <1>;
> };
> diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
> index 39cbc1238b92..d4a6ddbfd872 100644
> --- a/drivers/rtc/rtc-sun6i.c
> +++ b/drivers/rtc/rtc-sun6i.c
> @@ -73,6 +73,9 @@
> #define SUN6I_ALARM_CONFIG 0x0050
> #define SUN6I_ALARM_CONFIG_WAKEUP BIT(0)
>
> +#define SUN6I_LOSC_OUT_GATING 0x0060
> +#define SUN6I_LOSC_OUT_GATING_EN BIT(0)
> +
> /*
> * Get date values
> */
> @@ -125,6 +128,7 @@ struct sun6i_rtc_dev {
> struct clk_hw hw;
> struct clk_hw *int_osc;
> struct clk *losc;
> + struct clk *ext_losc;
>
> spinlock_t lock;
> };
> @@ -188,6 +192,7 @@ static void __init sun6i_rtc_clk_init(struct device_node *node)
> struct clk_init_data init = {
> .ops = &sun6i_rtc_osc_ops,
> };
> + const char *clkout_name = "osc32k-out";
> const char *parents[2];
>
> rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
> @@ -195,7 +200,7 @@ static void __init sun6i_rtc_clk_init(struct device_node *node)
> return;
> spin_lock_init(&rtc->lock);
>
> - clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws),
> + clk_data = kzalloc(sizeof(*clk_data) + (sizeof(*clk_data->hws) * 2),
> GFP_KERNEL);
> if (!clk_data)
> return;
> @@ -235,7 +240,8 @@ static void __init sun6i_rtc_clk_init(struct device_node *node)
>
> init.parent_names = parents;
> init.num_parents = of_clk_get_parent_count(node) + 1;
> - of_property_read_string(node, "clock-output-names", &init.name);
> + of_property_read_string_index(node, "clock-output-names", 0,
> + &init.name);
>
> rtc->losc = clk_register(NULL, &rtc->hw);
> if (IS_ERR(rtc->losc)) {
> @@ -243,8 +249,20 @@ static void __init sun6i_rtc_clk_init(struct device_node *node)
> return;
> }
>
> - clk_data->num = 1;
> + of_property_read_string_index(node, "clock-output-names", 1,
> + &clkout_name);
> + rtc->ext_losc = clk_register_gate(NULL, clkout_name, rtc->hw.init->name,
> + 0, rtc->base + SUN6I_LOSC_OUT_GATING,
> + SUN6I_LOSC_OUT_GATING_EN, 0,
> + &rtc->lock);
> + if (IS_ERR(rtc->ext_losc)) {
> + pr_crit("Couldn't register the LOSC external gate\n");
> + return;
> + }
> +
> + clk_data->num = 2;
> clk_data->hws[0] = &rtc->hw;
> + clk_data->hws[1] = __clk_get_hw(rtc->ext_losc);
> of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
> }
> CLK_OF_DECLARE_DRIVER(sun6i_rtc_clk, "allwinner,sun6i-a31-rtc",
> --
> 2.13.5
>

--
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com