[RESEND] clk: rockchip: disable init state before mmc card initialization
diff mbox

Message ID 1440404863-14350-1-git-send-email-shawn.lin@rock-chips.com
State New
Headers show

Commit Message

Shawn Lin Aug. 24, 2015, 8:27 a.m. UTC
mmc host controller's IO input/output timing is unpredictable if
bootloader execute tuning for HS200 mode. It might make kernel failed
to initialize mmc card in identification mode. The root cause is
tuning phase and degree setting for HS200 mode in bootloader aren't
applicable to that of identification mode in kernel stage. Anyway, we
can't force all bootloaders to disable tuning phase and degree setting
before into kernel. Simply disable it in rockchip_clk_register_mmc.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>

---

 drivers/clk/rockchip/clk-mmc-phase.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

Comments

Heiko Stuebner Aug. 24, 2015, 10:01 a.m. UTC | #1
Hi Shawn,

Am Montag, 24. August 2015, 16:27:43 schrieb Shawn Lin:
> mmc host controller's IO input/output timing is unpredictable if
> bootloader execute tuning for HS200 mode. It might make kernel failed
> to initialize mmc card in identification mode. The root cause is
> tuning phase and degree setting for HS200 mode in bootloader aren't
> applicable to that of identification mode in kernel stage. Anyway, we
> can't force all bootloaders to disable tuning phase and degree setting
> before into kernel. Simply disable it in rockchip_clk_register_mmc.
> 
> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> 
> ---
> 
>  drivers/clk/rockchip/clk-mmc-phase.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/clk/rockchip/clk-mmc-phase.c
> b/drivers/clk/rockchip/clk-mmc-phase.c index e9f8df32..ae21592 100644
> --- a/drivers/clk/rockchip/clk-mmc-phase.c
> +++ b/drivers/clk/rockchip/clk-mmc-phase.c
> @@ -38,6 +38,9 @@ static unsigned long rockchip_mmc_recalc(struct clk_hw
> *hw, #define ROCKCHIP_MMC_DEGREE_MASK 0x3
>  #define ROCKCHIP_MMC_DELAYNUM_OFFSET 2
>  #define ROCKCHIP_MMC_DELAYNUM_MASK (0xff << ROCKCHIP_MMC_DELAYNUM_OFFSET)
> +#define ROCKCHIP_MMC_INIT_STATE_DISABLE (0x1)
> +#define ROCKCHIP_MMC_INIT_STATE_SHIFT (1)
> +#define ROCKCHIP_MMC_INIT_STATE_MASK  (0x1)

you don't need the "()" around primitive values. Also I don't think you need 
the second MASK attribute, doing
	writel(HIWORD_UPDATE(ROCKCHIP_MMC_INIT_STATE_DISABLE,
				     ROCKCHIP_MMC_INIT_STATE_DISABLE,
				     mmc_clock->shift),

should be enough. And thirdly I'm undecided about the naming of the constant. 
The manual describes the init_state as "Assert init_state to soft reset the 
CLKGEN.", so I guess I'd prefer

	ROCKCHIP_MMC_INIT_STATE_RESET

or so

> 
>  #define PSECS_PER_SEC 1000000000000LL
> 
> @@ -119,6 +122,21 @@ static const struct clk_ops rockchip_mmc_clk_ops = {
>  	.set_phase	= rockchip_mmc_set_phase,
>  };
> 
> +static void rockchip_clk_mmc_disable_init(struct rockchip_mmc_clock

I guess similar to the thoughts above, simply name this
	rockchip_clk_mmc_reset()

or alternatively just do the reset in rockchip_clk_register_mmc directly:

if (mmc_clock->shift == ROCKCHIP_MMC_INIT_STATE_SHIFT))
	writel(HIWORD_UPDATE(ROCKCHIP_MMC_INIT_STATE_DISABLE,
				     ROCKCHIP_MMC_INIT_STATE_MASK,
			     mmc_clock->shift),
	       mmc_clock->reg);

as the pr_debug does not really serve a purpose.


Heiko

> *mmc_clock) +{
> +	if (mmc_clock->shift != ROCKCHIP_MMC_INIT_STATE_SHIFT)
> +		return;
> +
> +	writel(HIWORD_UPDATE(ROCKCHIP_MMC_INIT_STATE_DISABLE,
> +			     ROCKCHIP_MMC_INIT_STATE_MASK,
> +			     mmc_clock->shift),
> +	       mmc_clock->reg);
> +
> +	pr_debug("%s: clear mmc init state to %d", __func__,
> +		 (readl(mmc_clock->reg) >> (mmc_clock->shift)) &
> +		 ROCKCHIP_MMC_INIT_STATE_MASK);
> +}
> +
>  struct clk *rockchip_clk_register_mmc(const char *name,
>  				const char *const *parent_names, u8 num_parents,
>  				void __iomem *reg, int shift)
> @@ -139,6 +157,8 @@ struct clk *rockchip_clk_register_mmc(const char *name,
>  	mmc_clock->reg = reg;
>  	mmc_clock->shift = shift;
> 
> +	rockchip_clk_mmc_disable_init(mmc_clock);
> +
>  	if (name)
>  		init.name = name;
Shawn Lin Aug. 24, 2015, 2:02 p.m. UTC | #2
On 2015/8/24 18:01, Heiko Stuebner wrote:
> Hi Shawn,
>
> Am Montag, 24. August 2015, 16:27:43 schrieb Shawn Lin:
>> mmc host controller's IO input/output timing is unpredictable if
>> bootloader execute tuning for HS200 mode. It might make kernel failed
>> to initialize mmc card in identification mode. The root cause is
>> tuning phase and degree setting for HS200 mode in bootloader aren't
>> applicable to that of identification mode in kernel stage. Anyway, we
>> can't force all bootloaders to disable tuning phase and degree setting
>> before into kernel. Simply disable it in rockchip_clk_register_mmc.
>>
>> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>>
>> ---
>>
>>   drivers/clk/rockchip/clk-mmc-phase.c | 20 ++++++++++++++++++++
>>   1 file changed, 20 insertions(+)
>>
>> diff --git a/drivers/clk/rockchip/clk-mmc-phase.c
>> b/drivers/clk/rockchip/clk-mmc-phase.c index e9f8df32..ae21592 100644
>> --- a/drivers/clk/rockchip/clk-mmc-phase.c
>> +++ b/drivers/clk/rockchip/clk-mmc-phase.c
>> @@ -38,6 +38,9 @@ static unsigned long rockchip_mmc_recalc(struct clk_hw
>> *hw, #define ROCKCHIP_MMC_DEGREE_MASK 0x3
>>   #define ROCKCHIP_MMC_DELAYNUM_OFFSET 2
>>   #define ROCKCHIP_MMC_DELAYNUM_MASK (0xff << ROCKCHIP_MMC_DELAYNUM_OFFSET)
>> +#define ROCKCHIP_MMC_INIT_STATE_DISABLE (0x1)
>> +#define ROCKCHIP_MMC_INIT_STATE_SHIFT (1)
>> +#define ROCKCHIP_MMC_INIT_STATE_MASK  (0x1)
>
> you don't need the "()" around primitive values. Also I don't think you need
> the second MASK attribute, doing
> 	writel(HIWORD_UPDATE(ROCKCHIP_MMC_INIT_STATE_DISABLE,
> 				     ROCKCHIP_MMC_INIT_STATE_DISABLE,
> 				     mmc_clock->shift),
>
> should be enough. And thirdly I'm undecided about the naming of the constant.
> The manual describes the init_state as "Assert init_state to soft reset the
> CLKGEN.", so I guess I'd prefer
>
> 	ROCKCHIP_MMC_INIT_STATE_RESET

Thanks, Heiko.

Actually, I'm either not so sure how to naming this bit since if we are 
used to calling a bit, reset bit, which I thought it should at least do 
some reset either to state machine or to register value. But obvious it 
doesn't. Moreover, Assert/Dis-assert seems like disable/enable from my 
point. Anyway, ROCKCHIP_MMC_INIT_STATE_RESET is okay for me, but I think 
I should add some comments for these code.

>
> or so
>
>>
>>   #define PSECS_PER_SEC 1000000000000LL
>>
>> @@ -119,6 +122,21 @@ static const struct clk_ops rockchip_mmc_clk_ops = {
>>   	.set_phase	= rockchip_mmc_set_phase,
>>   };
>>
>> +static void rockchip_clk_mmc_disable_init(struct rockchip_mmc_clock
>
> I guess similar to the thoughts above, simply name this
> 	rockchip_clk_mmc_reset()
>
> or alternatively just do the reset in rockchip_clk_register_mmc directly:
>
> if (mmc_clock->shift == ROCKCHIP_MMC_INIT_STATE_SHIFT))
> 	writel(HIWORD_UPDATE(ROCKCHIP_MMC_INIT_STATE_DISABLE,
> 				     ROCKCHIP_MMC_INIT_STATE_MASK,
> 			     mmc_clock->shift),
> 	       mmc_clock->reg);
>
> as the pr_debug does not really serve a purpose.
>

Okay, rockchip_clk_mmc_reset is coming in v2 :)

>
> Heiko
>
>> *mmc_clock) +{
>> +	if (mmc_clock->shift != ROCKCHIP_MMC_INIT_STATE_SHIFT)
>> +		return;
>> +
>> +	writel(HIWORD_UPDATE(ROCKCHIP_MMC_INIT_STATE_DISABLE,
>> +			     ROCKCHIP_MMC_INIT_STATE_MASK,
>> +			     mmc_clock->shift),
>> +	       mmc_clock->reg);
>> +
>> +	pr_debug("%s: clear mmc init state to %d", __func__,
>> +		 (readl(mmc_clock->reg) >> (mmc_clock->shift)) &
>> +		 ROCKCHIP_MMC_INIT_STATE_MASK);
>> +}
>> +
>>   struct clk *rockchip_clk_register_mmc(const char *name,
>>   				const char *const *parent_names, u8 num_parents,
>>   				void __iomem *reg, int shift)
>> @@ -139,6 +157,8 @@ struct clk *rockchip_clk_register_mmc(const char *name,
>>   	mmc_clock->reg = reg;
>>   	mmc_clock->shift = shift;
>>
>> +	rockchip_clk_mmc_disable_init(mmc_clock);
>> +
>>   	if (name)
>>   		init.name = name;
>
>
>
>

Patch
diff mbox

diff --git a/drivers/clk/rockchip/clk-mmc-phase.c b/drivers/clk/rockchip/clk-mmc-phase.c
index e9f8df32..ae21592 100644
--- a/drivers/clk/rockchip/clk-mmc-phase.c
+++ b/drivers/clk/rockchip/clk-mmc-phase.c
@@ -38,6 +38,9 @@  static unsigned long rockchip_mmc_recalc(struct clk_hw *hw,
 #define ROCKCHIP_MMC_DEGREE_MASK 0x3
 #define ROCKCHIP_MMC_DELAYNUM_OFFSET 2
 #define ROCKCHIP_MMC_DELAYNUM_MASK (0xff << ROCKCHIP_MMC_DELAYNUM_OFFSET)
+#define ROCKCHIP_MMC_INIT_STATE_DISABLE (0x1)
+#define ROCKCHIP_MMC_INIT_STATE_SHIFT (1)
+#define ROCKCHIP_MMC_INIT_STATE_MASK  (0x1)
 
 #define PSECS_PER_SEC 1000000000000LL
 
@@ -119,6 +122,21 @@  static const struct clk_ops rockchip_mmc_clk_ops = {
 	.set_phase	= rockchip_mmc_set_phase,
 };
 
+static void rockchip_clk_mmc_disable_init(struct rockchip_mmc_clock *mmc_clock)
+{
+	if (mmc_clock->shift != ROCKCHIP_MMC_INIT_STATE_SHIFT)
+		return;
+
+	writel(HIWORD_UPDATE(ROCKCHIP_MMC_INIT_STATE_DISABLE,
+			     ROCKCHIP_MMC_INIT_STATE_MASK,
+			     mmc_clock->shift),
+	       mmc_clock->reg);
+
+	pr_debug("%s: clear mmc init state to %d", __func__,
+		 (readl(mmc_clock->reg) >> (mmc_clock->shift)) &
+		 ROCKCHIP_MMC_INIT_STATE_MASK);
+}
+
 struct clk *rockchip_clk_register_mmc(const char *name,
 				const char *const *parent_names, u8 num_parents,
 				void __iomem *reg, int shift)
@@ -139,6 +157,8 @@  struct clk *rockchip_clk_register_mmc(const char *name,
 	mmc_clock->reg = reg;
 	mmc_clock->shift = shift;
 
+	rockchip_clk_mmc_disable_init(mmc_clock);
+
 	if (name)
 		init.name = name;