| Message ID | 20240412192641.2912914-1-curtis.machida@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Jaehoon Chung |
| Headers | show |
| Series | mmc: sdhci: programmable clock calculation needs multiplier +1 | expand |
> -----Original Message----- > From: curtis.machida@intel.com <curtis.machida@intel.com> > Sent: Saturday, April 13, 2024 4:27 AM > To: u-boot@lists.denx.de; Peng Fan <peng.fan@nxp.com>; Jaehoon Chung <jh80.chung@samsung.com> > Cc: cmachida <curtis.machida@intel.com>; Jonas Karlman <jonas@kwiboo.se>; Kever Yang <kever.yang@rock- > chips.com>; Peter Geis <pgwipeout@gmail.com>; Sean Anderson <sean.anderson@seco.com>; Simon Glass > <sjg@chromium.org>; Tom Rini <trini@konsulko.com> > Subject: [PATCH] mmc: sdhci: programmable clock calculation needs multiplier +1 > > From: cmachida <curtis.machida@intel.com> > > According to the SD Host Controller Simplified Specification v4.20, > the multiplier value M is one more than the Clock Multiplier field. > > Copied code from Linux project. drivers/mmc/host/sdhci.c line 4405 > > Signed-off-by: cmachida <curtis.machida@intel.com> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com> Best Regards, Jaehoon Chung > --- > > drivers/mmc/sdhci.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c > index 0178ed8a11..a8476ec4e9 100644 > --- a/drivers/mmc/sdhci.c > +++ b/drivers/mmc/sdhci.c > @@ -929,6 +929,15 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host, > debug("%s, caps_1: 0x%x\n", __func__, caps_1); > host->clk_mul = (caps_1 & SDHCI_CLOCK_MUL_MASK) >> > SDHCI_CLOCK_MUL_SHIFT; > + > + /* > + * In case the value in Clock Multiplier is 0, then programmable > + * clock mode is not supported, otherwise the actual clock > + * multiplier is one more than the value of Clock Multiplier > + * in the Capabilities Register. > + */ > + if (host->clk_mul) > + host->clk_mul += 1; > } > > if (host->max_clk == 0) { > -- > 2.43.2
On 4/12/24 15:26, curtis.machida@intel.com wrote: > [You don't often get email from curtis.machida@intel.com. Learn why this is important at https://cas5-0-urlprotect.trendmicro.com:443/wis/clicktime/v1/query?url=https%3a%2f%2faka.ms%2fLearnAboutSenderIdentification&umid=4f25273f-b33b-4eb3-8643-c1f6eff8842b&auth=d807158c60b7d2502abde8a2fc01f40662980862-c95c2e418b830130ad99c91e42b2732e3f7e44ee ] > > From: cmachida <curtis.machida@intel.com> > > According to the SD Host Controller Simplified Specification v4.20, > the multiplier value M is one more than the Clock Multiplier field. > > Copied code from Linux project. drivers/mmc/host/sdhci.c line 4405 > > Signed-off-by: cmachida <curtis.machida@intel.com> > --- > > drivers/mmc/sdhci.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c > index 0178ed8a11..a8476ec4e9 100644 > --- a/drivers/mmc/sdhci.c > +++ b/drivers/mmc/sdhci.c > @@ -929,6 +929,15 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host, > debug("%s, caps_1: 0x%x\n", __func__, caps_1); > host->clk_mul = (caps_1 & SDHCI_CLOCK_MUL_MASK) >> > SDHCI_CLOCK_MUL_SHIFT; > + > + /* > + * In case the value in Clock Multiplier is 0, then programmable > + * clock mode is not supported, otherwise the actual clock > + * multiplier is one more than the value of Clock Multiplier > + * in the Capabilities Register. > + */ > + if (host->clk_mul) > + host->clk_mul += 1; > } > > if (host->max_clk == 0) { > -- > 2.43.2 > Reviewed-by: Sean Anderson <sean.anderson@seco.com>
diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c index 0178ed8a11..a8476ec4e9 100644 --- a/drivers/mmc/sdhci.c +++ b/drivers/mmc/sdhci.c @@ -929,6 +929,15 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host, debug("%s, caps_1: 0x%x\n", __func__, caps_1); host->clk_mul = (caps_1 & SDHCI_CLOCK_MUL_MASK) >> SDHCI_CLOCK_MUL_SHIFT; + + /* + * In case the value in Clock Multiplier is 0, then programmable + * clock mode is not supported, otherwise the actual clock + * multiplier is one more than the value of Clock Multiplier + * in the Capabilities Register. + */ + if (host->clk_mul) + host->clk_mul += 1; } if (host->max_clk == 0) {