[U-Boot] [PATCH] mmc: fsl_esdhc: Fix i.MX53 eSDHCv3 clock
Commit 4f425280fa71 ("mmc: fsl_esdhc: Allow all supported prescaler values") made it possible to set SYSCTL.SDCLKFS to 0 in SDR mode on i.MX, thus bypassing the SD clock frequency prescaler, in order to be able to get higher SD clock frequencies in some contexts. However, that commit missed the fact that this value is illegal on the eSDHCv3 instance of the i.MX53. This seems to be the only exception on i.MX, this value being legal even for the eSDHCv2 instances of the i.MX53.
Fix this issue by changing the minimum prescaler value for the single instance of the i.MX53 eSDHCv3 controller.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau.dev@gmail.com --- drivers/mmc/fsl_esdhc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 499d622c6d..90425e8a30 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -528,14 +528,19 @@ out:
static void set_sysctl(struct fsl_esdhc_priv *priv, struct mmc *mmc, uint clock) { + struct fsl_esdhc *regs = priv->esdhc_regs; int div = 1; #ifdef ARCH_MXC +#ifdef CONFIG_MX53 + /* For i.MX53 eSDHCv3, SYSCTL.SDCLKFS may not be set to 0. */ + int pre_div = regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR ? 2 : 1; +#else int pre_div = 1; +#endif #else int pre_div = 2; #endif int ddr_pre_div = mmc->ddr_mode ? 2 : 1; - struct fsl_esdhc *regs = priv->esdhc_regs; int sdhc_clk = priv->sdhc_clk; uint clk;
+ Adding Jaehoon, who is the U-Boot MMC maintainer.
On Sun, Jan 14, 2018 at 9:46 PM, Benoît Thébaudeau benoit.thebaudeau.dev@gmail.com wrote:
Commit 4f425280fa71 ("mmc: fsl_esdhc: Allow all supported prescaler values") made it possible to set SYSCTL.SDCLKFS to 0 in SDR mode on i.MX, thus bypassing the SD clock frequency prescaler, in order to be able to get higher SD clock frequencies in some contexts. However, that commit missed the fact that this value is illegal on the eSDHCv3 instance of the i.MX53. This seems to be the only exception on i.MX, this value being legal even for the eSDHCv2 instances of the i.MX53.
Fix this issue by changing the minimum prescaler value for the single instance of the i.MX53 eSDHCv3 controller.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau.dev@gmail.com
Thanks for your fix in U-Boot and in the kernel:
Reviewed-by: Fabio Estevam fabio.estevam@nxp.com
drivers/mmc/fsl_esdhc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 499d622c6d..90425e8a30 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -528,14 +528,19 @@ out:
static void set_sysctl(struct fsl_esdhc_priv *priv, struct mmc *mmc, uint clock) {
struct fsl_esdhc *regs = priv->esdhc_regs; int div = 1;#ifdef ARCH_MXC +#ifdef CONFIG_MX53
/* For i.MX53 eSDHCv3, SYSCTL.SDCLKFS may not be set to 0. */int pre_div = regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR ? 2 : 1;+#else int pre_div = 1; +#endif #else int pre_div = 2; #endif int ddr_pre_div = mmc->ddr_mode ? 2 : 1;
struct fsl_esdhc *regs = priv->esdhc_regs; int sdhc_clk = priv->sdhc_clk; uint clk;-- 2.14.1
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Hi Benoît,
On 15/01/2018 00:46, Benoît Thébaudeau wrote:
Commit 4f425280fa71 ("mmc: fsl_esdhc: Allow all supported prescaler values") made it possible to set SYSCTL.SDCLKFS to 0 in SDR mode on i.MX, thus bypassing the SD clock frequency prescaler, in order to be able to get higher SD clock frequencies in some contexts. However, that commit missed the fact that this value is illegal on the eSDHCv3 instance of the i.MX53. This seems to be the only exception on i.MX, this value being legal even for the eSDHCv2 instances of the i.MX53.
Fix this issue by changing the minimum prescaler value for the single instance of the i.MX53 eSDHCv3 controller.
Signed-off-by: Benoît Thébaudeau benoit.thebaudeau.dev@gmail.com
drivers/mmc/fsl_esdhc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/fsl_esdhc.c b/drivers/mmc/fsl_esdhc.c index 499d622c6d..90425e8a30 100644 --- a/drivers/mmc/fsl_esdhc.c +++ b/drivers/mmc/fsl_esdhc.c @@ -528,14 +528,19 @@ out:
static void set_sysctl(struct fsl_esdhc_priv *priv, struct mmc *mmc, uint clock) {
- struct fsl_esdhc *regs = priv->esdhc_regs; int div = 1;
#ifdef ARCH_MXC +#ifdef CONFIG_MX53
- /* For i.MX53 eSDHCv3, SYSCTL.SDCLKFS may not be set to 0. */
- int pre_div = regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR ? 2 : 1;
It is surely a question of taste - but is it not cleared to surround the expression with parenthesis ? (regs == .... )
+#else int pre_div = 1; +#endif #else int pre_div = 2; #endif int ddr_pre_div = mmc->ddr_mode ? 2 : 1;
- struct fsl_esdhc *regs = priv->esdhc_regs; int sdhc_clk = priv->sdhc_clk; uint clk;
Best regards, Stefano
Hi Stefano,
On Mon, Jan 15, 2018 at 11:59 AM, Stefano Babic sbabic@denx.de wrote:
On 15/01/2018 00:46, Benoît Thébaudeau wrote:
int pre_div = regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR ? 2 : 1;It is surely a question of taste - but is it not cleared to surround the expression with parenthesis ? (regs == .... )
I can send a v2 for that if you want. Which of the following do you prefer (personally, I'd say the last one)?
int pre_div = (regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR ? 2 : 1); int pre_div = (regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR) ? 2 : 1;
Note that this patch can be tested with the 2nd MMC on i.MX53 Loco if anyone has this board. Wladimir?
Best regards, Benoît
Hi Benoît,
On 15/01/2018 22:11, Benoît Thébaudeau wrote:
Hi Stefano,
On Mon, Jan 15, 2018 at 11:59 AM, Stefano Babic sbabic@denx.de wrote:
On 15/01/2018 00:46, Benoît Thébaudeau wrote:
int pre_div = regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR ? 2 : 1;It is surely a question of taste - but is it not cleared to surround the expression with parenthesis ? (regs == .... )
I can send a v2 for that if you want. Which of the following do you prefer (personally, I'd say the last one)?
int pre_div = (regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR ? 2 : 1); int pre_div = (regs == (struct fsl_esdhc *)MMC_SDHC3_BASE_ADDR) ? 2 : 1;
I agree for last one - but as I said, it is just a question of taste.
Note that this patch can be tested with the 2nd MMC on i.MX53 Loco if anyone has this board. Wladimir?
Best regards, Stefano
participants (3)
-
Benoît Thébaudeau -
Fabio Estevam -
Stefano Babic