[PATCH v2 1/2] clk: exynos5433: do not use CLK_IGNORE_UNUSED for SPI clocks

[PATCH v2 1/2] clk: exynos5433: do not use CLK_IGNORE_UNUSED for SPI clocks

[Andi Shyti]

The CLK_IGNORE_UNUSED flag has to be avoided whenever possible.
Use the CLK_IS_CRITICAL flag instead, which enables the clock line
during boot time.

While none of the SCLK_SPI need to be alive all the time as that
clock is handled by the SPI driver as a busclk whenever needed.

Suggested-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
---

Hi,

this patch comes after Tomasz's review where he discouraged from
using the CLK_IGNORE_UNUSED flag. Therefore I added one more
patch to the original where I remove that flag for the SPI1
whenever not necessary while I replace it with the
CLK_IS_CRITICAL for the ioclk.

This patch makes this driver the first using the "critical"
functionality :)

Andi

 drivers/clk/samsung/clk-exynos5433.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/samsung/clk-exynos5433.c b/drivers/clk/samsung/clk-exynos5433.c
index 128527b..dcb4391 100644
--- a/drivers/clk/samsung/clk-exynos5433.c
+++ b/drivers/clk/samsung/clk-exynos5433.c
@@ -1655,7 +1655,7 @@ static struct samsung_gate_clock peric_gate_clks[] __initdata = {
 			ENABLE_SCLK_PERIC, 13, CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_IOCLK_SPI1, "sclk_ioclk_spi1", "ioclk_spi1_clk_in",
 			ENABLE_SCLK_PERIC, 12,
-			CLK_IGNORE_UNUSED | CLK_SET_RATE_PARENT, 0),
+			CLK_IS_CRITICAL | CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_IOCLK_SPI0, "sclk_ioclk_spi0", "ioclk_spi0_clk_in",
 			ENABLE_SCLK_PERIC, 11, CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_IOCLK_I2S1_BCLK, "sclk_ioclk_i2s1_bclk",
@@ -1670,7 +1670,7 @@ static struct samsung_gate_clock peric_gate_clks[] __initdata = {
 	GATE(CLK_SCLK_SPI2, "sclk_spi2", "sclk_spi2_peric", ENABLE_SCLK_PERIC,
 			5, CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_SPI1, "sclk_spi1", "sclk_spi1_peric", ENABLE_SCLK_PERIC,
-			4, CLK_IGNORE_UNUSED | CLK_SET_RATE_PARENT, 0),
+			4, CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_SPI0, "sclk_spi0", "sclk_spi0_peric", ENABLE_SCLK_PERIC,
 			3, CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_UART2, "sclk_uart2", "sclk_uart2_peric",
-- 
2.8.1

[PATCH v2 2/2] clk: exynos5433: enable sclk_ioclk for SPI3

[Andi Shyti]

enable SPI3 iosclk by using the CLK_IS_CRITICAL flag.
There is no device which is supposed to enable this clock when
needed, therefore, the only way to use the SPI bus is to enable
it in boot time.

Suggested-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---

Hi,

V1 -> V2

- the "sclk_spi3" doesn't need to be enabled in boot time as it
  is handled by the spi driver itself.

- use the CLK_IS_CRITICAL flag for the ioclk

Andi

 drivers/clk/samsung/clk-exynos5433.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/samsung/clk-exynos5433.c b/drivers/clk/samsung/clk-exynos5433.c
index dcb4391..c33150e 100644
--- a/drivers/clk/samsung/clk-exynos5433.c
+++ b/drivers/clk/samsung/clk-exynos5433.c
@@ -1641,7 +1641,8 @@ static struct samsung_gate_clock peric_gate_clks[] __initdata = {
 	GATE(CLK_SCLK_IOCLK_SPI4, "sclk_ioclk_spi4", "ioclk_spi4_clk_in",
 			ENABLE_SCLK_PERIC, 21, CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_IOCLK_SPI3, "sclk_ioclk_spi3", "ioclk_spi3_clk_in",
-			ENABLE_SCLK_PERIC, 20, CLK_SET_RATE_PARENT, 0),
+			ENABLE_SCLK_PERIC, 20,
+			CLK_IS_CRITICAL | CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_SPI4, "sclk_spi4", "sclk_spi4_peric", ENABLE_SCLK_PERIC,
 			19, CLK_SET_RATE_PARENT, 0),
 	GATE(CLK_SCLK_SPI3, "sclk_spi3", "sclk_spi3_peric", ENABLE_SCLK_PERIC,
-- 
2.8.1

Re: [PATCH v2 2/2] clk: exynos5433: enable sclk_ioclk for SPI3

[Chanwoo Choi]

Hi Andi,

2016-06-27 22:03 GMT+09:00 Andi Shyti <andi.shyti@samsung.com>:
> enable SPI3 iosclk by using the CLK_IS_CRITICAL flag.

s/iosclk/ioclk

> There is no device which is supposed to enable this clock when
> needed, therefore, the only way to use the SPI bus is to enable
> it in boot time.
>
> Suggested-by: Tomasz Figa <tomasz.figa@gmail.com>
> Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
>
> Hi,
>
> V1 -> V2
>
> - the "sclk_spi3" doesn't need to be enabled in boot time as it
>   is handled by the spi driver itself.
>
> - use the CLK_IS_CRITICAL flag for the ioclk
>
> Andi
>
>  drivers/clk/samsung/clk-exynos5433.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/samsung/clk-exynos5433.c b/drivers/clk/samsung/clk-exynos5433.c
> index dcb4391..c33150e 100644
> --- a/drivers/clk/samsung/clk-exynos5433.c
> +++ b/drivers/clk/samsung/clk-exynos5433.c
> @@ -1641,7 +1641,8 @@ static struct samsung_gate_clock peric_gate_clks[] __initdata = {
>         GATE(CLK_SCLK_IOCLK_SPI4, "sclk_ioclk_spi4", "ioclk_spi4_clk_in",
>                         ENABLE_SCLK_PERIC, 21, CLK_SET_RATE_PARENT, 0),
>         GATE(CLK_SCLK_IOCLK_SPI3, "sclk_ioclk_spi3", "ioclk_spi3_clk_in",
> -                       ENABLE_SCLK_PERIC, 20, CLK_SET_RATE_PARENT, 0),
> +                       ENABLE_SCLK_PERIC, 20,
> +                       CLK_IS_CRITICAL | CLK_SET_RATE_PARENT, 0),
>         GATE(CLK_SCLK_SPI4, "sclk_spi4", "sclk_spi4_peric", ENABLE_SCLK_PERIC,
>                         19, CLK_SET_RATE_PARENT, 0),
>         GATE(CLK_SCLK_SPI3, "sclk_spi3", "sclk_spi3_peric", ENABLE_SCLK_PERIC,

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>

Thanks,
Chanwoo Choi

Re: [PATCH v2 1/2] clk: exynos5433: do not use CLK_IGNORE_UNUSED for SPI clocks

[Andi Shyti]

Hi,

On Mon, Jun 27, 2016 at 10:03:13PM +0900, Andi Shyti wrote:
> The CLK_IGNORE_UNUSED flag has to be avoided whenever possible.
> Use the CLK_IS_CRITICAL flag instead, which enables the clock line
> during boot time.
> 
> While none of the SCLK_SPI need to be alive all the time as that
> clock is handled by the SPI driver as a busclk whenever needed.
> 
> Suggested-by: Tomasz Figa <tomasz.figa@gmail.com>
> Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
> ---

sorry for spamming, please ignore this patch, some more testing
has shown that if the SCLK_SPI1 is not kept alive, the device not
always works.

Thanks and sorry again,
Andi