From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ritesh Harjani Subject: Re: [PATCH v3 8/9] mmc: sdhci-msm: Add clock changes for DDR mode. Date: Fri, 19 Aug 2016 18:56:31 +0530 Message-ID: <23f3d9df-671b-ae81-d340-3cc858a94782@codeaurora.org> References: <1471581384-18961-1-git-send-email-riteshh@codeaurora.org> <1471581384-18961-9-git-send-email-riteshh@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org To: Adrian Hunter Cc: ulf.hansson@linaro.org, bjorn.andersson@linaro.org, shawn.lin@rock-chips.com, jh80.chung@samsung.com, linux-mmc@vger.kernel.org, linux-arm-msm@vger.kernel.org, georgi.djakov@linaro.org, alex.lemberg@sandisk.com, mateusz.nowak@intel.com, Yuliy.Izrailov@sandisk.com, asutoshd@codeaurora.org, kdorfman@codeaurora.org, david.griego@linaro.org, stummala@codeaurora.org, venkatg@codeaurora.org List-Id: linux-arm-msm@vger.kernel.org Hi Adrian, Thanks for the review. On 8/19/2016 6:34 PM, Adrian Hunter wrote: > On 19/08/16 07:36, Ritesh Harjani wrote: >> SDHC MSM controller need 2x clock for MCLK at GCC. >> Hence make required changes to have 2x clock for >> DDR timing modes. >> >> Signed-off-by: Ritesh Harjani >> --- >> drivers/mmc/host/sdhci-msm.c | 22 ++++++++++++++++++---- >> 1 file changed, 18 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c >> index c0ad9c2..f0e6293 100644 >> --- a/drivers/mmc/host/sdhci-msm.c >> +++ b/drivers/mmc/host/sdhci-msm.c >> @@ -661,21 +661,35 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock) >> { >> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); >> struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); >> - u32 msm_clock = 0; >> + struct mmc_ios curr_ios = host->mmc->ios; >> + u32 msm_clock = clock, ddr_clock = 0; > > Don't need to initialize msm_clock or ddr_clock Sure. Will do that. > >> int rc = 0; >> >> if (!clock) >> goto out; >> >> - if (clock != msm_host->clk_rate) { >> - msm_clock = sdhci_msm_get_msm_clk_rate(host, clock); >> + msm_clock = sdhci_msm_get_msm_clk_rate(host, clock); >> + if ((curr_ios.timing == MMC_TIMING_UHS_DDR50) || >> + (curr_ios.timing == MMC_TIMING_MMC_DDR52) || >> + (curr_ios.timing == MMC_TIMING_MMC_HS400)) { >> + /* >> + * The SDHC requires internal clock frequency to be double the >> + * actual clock that will be set for DDR mode. The controller >> + * uses the faster clock(100/400MHz) for some of its parts and >> + * send the actual required clock (50/200MHz) to the card. >> + */ >> + ddr_clock = clock * 2; >> + msm_clock = sdhci_msm_get_msm_clk_rate(host, ddr_clock); >> + } >> + >> + if (msm_clock != msm_host->clk_rate) { >> rc = clk_set_rate(msm_host->clk, msm_clock); >> if (rc) { >> pr_err("%s: failed to set clock at rate %u, requested clock rate %u\n", >> mmc_hostname(host->mmc), msm_clock, clock); >> goto out; >> } >> - msm_host->clk_rate = clock; >> + msm_host->clk_rate = msm_clock; >> pr_debug("%s: setting clock at rate %lu\n", >> mmc_hostname(host->mmc), clk_get_rate(msm_host->clk)); >> } >> >