Re: [PATCH 15/15] clk: pistachio: Fix wrong SDHost card speed

From: Rob Herring
Date: Tue Jul 31 2018 - 17:22:00 EST


On Sun, Jul 22, 2018 at 11:20:10PM +0200, Andreas Färber wrote:
> From: Govindraj Raja <Govindraj.Raja@xxxxxxxxxx>
>
> The SDHost currently clocks the card 4x slower than it
> should do, because there is a fixed divide by 4 in the
> sdhost wrapper that is not present in the clock tree.
> To model this, add a fixed divide by 4 clock node in
> the SDHost clock path.
>
> This will ensure the right clock frequency is selected when
> the mmc driver tries to configure frequency on card insert.
>
> Signed-off-by: Govindraj Raja <Govindraj.Raja@xxxxxxxxxx>
> Signed-off-by: Andreas Färber <afaerber@xxxxxxx>
> ---
> drivers/clk/pistachio/clk-pistachio.c | 3 ++-
> include/dt-bindings/clock/pistachio-clk.h | 1 +
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/pistachio/clk-pistachio.c b/drivers/clk/pistachio/clk-pistachio.c
> index c4ceb5eaf46c..1c968d9a6e17 100644
> --- a/drivers/clk/pistachio/clk-pistachio.c
> +++ b/drivers/clk/pistachio/clk-pistachio.c
> @@ -44,7 +44,7 @@ static struct pistachio_gate pistachio_gates[] __initdata = {
> GATE(CLK_AUX_ADC_INTERNAL, "aux_adc_internal", "sys_internal_div",
> 0x104, 22),
> GATE(CLK_AUX_ADC, "aux_adc", "aux_adc_div", 0x104, 23),
> - GATE(CLK_SD_HOST, "sd_host", "sd_host_div", 0x104, 24),
> + GATE(CLK_SD_HOST, "sd_host", "sd_host_div4", 0x104, 24),
> GATE(CLK_BT, "bt", "bt_div", 0x104, 25),
> GATE(CLK_BT_DIV4, "bt_div4", "bt_div4_div", 0x104, 26),
> GATE(CLK_BT_DIV8, "bt_div8", "bt_div8_div", 0x104, 27),
> @@ -54,6 +54,7 @@ static struct pistachio_gate pistachio_gates[] __initdata = {
> static struct pistachio_fixed_factor pistachio_ffs[] __initdata = {
> FIXED_FACTOR(CLK_WIFI_DIV4, "wifi_div4", "wifi_pll", 4),
> FIXED_FACTOR(CLK_WIFI_DIV8, "wifi_div8", "wifi_pll", 8),
> + FIXED_FACTOR(CLK_SDHOST_DIV4, "sd_host_div4", "sd_host_div", 4),
> };
>
> static struct pistachio_div pistachio_divs[] __initdata = {
> diff --git a/include/dt-bindings/clock/pistachio-clk.h b/include/dt-bindings/clock/pistachio-clk.h
> index 039f83facb68..77b92aed241d 100644
> --- a/include/dt-bindings/clock/pistachio-clk.h
> +++ b/include/dt-bindings/clock/pistachio-clk.h
> @@ -21,6 +21,7 @@
> /* Fixed-factor clocks */
> #define CLK_WIFI_DIV4 16
> #define CLK_WIFI_DIV8 17
> +#define CLK_SDHOST_DIV4 18

Does this clock really need to be exposed in DT?

>
> /* Gate clocks */
> #define CLK_MIPS 32
> --
> 2.16.4
>