From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gururaja Hebbar Subject: Re: [RESEND PATCH V2] mmc: omap_hsmmc: Enable HSPE bit for high speed cards Date: Wed, 31 Oct 2012 16:18:02 +0530 Message-ID: <509101E2.5050606@ti.com> References: <1351672116-17309-1-git-send-email-gururaja.hebbar@ti.com> <20121031100422.GA10094@arwen.pp.htv.fi> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121031100422.GA10094@arwen.pp.htv.fi> Sender: linux-omap-owner@vger.kernel.org To: balbi@ti.com Cc: svenkatr@ti.com, cjb@laptop.org, balajitk@ti.com, grant.likely@secretlab.ca, nsekhar@ti.com, sudhakar.raj@ti.com, linux-omap@vger.kernel.org, linux-mmc@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, rob.herring@calxeda.com List-Id: linux-mmc@vger.kernel.org On 10/31/2012 3:34 PM, Felipe Balbi wrote: > Hi, > > On Wed, Oct 31, 2012 at 01:58:35PM +0530, Hebbar, Gururaja wrote: >> HSMMC IP on AM33xx need a special setting to handle High-speed cards. >> Other platforms like TI81xx, OMAP4 may need this as-well. This depends >> on the HSMMC IP timing closure done for the high speed cards. >> >> From AM335x TRM (SPRUH73F - 18.3.12 Output Signals Generation) >> >> The MMC/SD/SDIO output signals can be driven on either falling edge or >> rising edge depending on the SD_HCTL[2] HSPE bit. This feature allows >> to reach better timing performance, and thus to increase data transfer >> frequency. >> >> There are few pre-requisites for enabling the HSPE bit >> - Controller should support High-Speed-Enable Bit and >> - Controller should not be using DDR Mode and >> - Controller should advertise that it supports High Speed in >> capabilities register and >> - MMC/SD clock coming out of controller > 25MHz >> >> Note: >> The implementation reuses the output of calc_divisor() so as to reduce >> code addition. >> >> Signed-off-by: Hebbar, Gururaja >> --- >> Rebased on mmc-next (v3.7.0-rc1) >> Only Build tested since EDMA support for AM335x is not yet added >> >> Changes in V2 >> - Added note in commit message about code re-use >> - replaced ((a & BIT(n) == BIT(n))) with (a & BIT(n)) since >> effectively both are same. >> >> :100644 100644 be76a23... ed271fc... M Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >> :100644 100644 8b4e4f2... 346af5b... M arch/arm/plat-omap/include/plat/mmc.h >> :100644 100644 54bfd0c... 5ea4c9d... M drivers/mmc/host/omap_hsmmc.c >> .../devicetree/bindings/mmc/ti-omap-hsmmc.txt | 1 + >> arch/arm/plat-omap/include/plat/mmc.h | 1 + >> drivers/mmc/host/omap_hsmmc.c | 30 +++++++++++++++++++- >> 3 files changed, 31 insertions(+), 1 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >> index be76a23..ed271fc 100644 >> --- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >> +++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt >> @@ -19,6 +19,7 @@ ti,dual-volt: boolean, supports dual voltage cards >> "supply-name" examples are "vmmc", "vmmc_aux" etc >> ti,non-removable: non-removable slot (like eMMC) >> ti,needs-special-reset: Requires a special softreset sequence >> +ti,needs-special-hs-handling: HSMMC IP needs special setting for handling High Speed >> >> Example: >> mmc1: mmc@0x4809c000 { >> diff --git a/arch/arm/plat-omap/include/plat/mmc.h b/arch/arm/plat-omap/include/plat/mmc.h >> index 8b4e4f2..346af5b 100644 >> --- a/arch/arm/plat-omap/include/plat/mmc.h >> +++ b/arch/arm/plat-omap/include/plat/mmc.h >> @@ -126,6 +126,7 @@ struct omap_mmc_platform_data { >> /* we can put the features above into this variable */ >> #define HSMMC_HAS_PBIAS (1 << 0) >> #define HSMMC_HAS_UPDATED_RESET (1 << 1) >> +#define HSMMC_HAS_HSPE_SUPPORT (1 << 2) >> unsigned features; >> >> int switch_pin; /* gpio (card detect) */ >> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c >> index 54bfd0c..5ea4c9d 100644 >> --- a/drivers/mmc/host/omap_hsmmc.c >> +++ b/drivers/mmc/host/omap_hsmmc.c >> @@ -62,6 +62,7 @@ >> >> #define VS18 (1 << 26) >> #define VS30 (1 << 25) >> +#define HSS (1 << 21) >> #define SDVS18 (0x5 << 9) >> #define SDVS30 (0x6 << 9) >> #define SDVS33 (0x7 << 9) >> @@ -89,6 +90,7 @@ >> #define MSBS (1 << 5) >> #define BCE (1 << 1) >> #define FOUR_BIT (1 << 1) >> +#define HSPE (1 << 2) >> #define DDR (1 << 19) >> #define DW8 (1 << 5) >> #define CC 0x1 >> @@ -489,6 +491,7 @@ static void omap_hsmmc_set_clock(struct omap_hsmmc_host *host) >> struct mmc_ios *ios = &host->mmc->ios; >> unsigned long regval; >> unsigned long timeout; >> + unsigned long clkdiv; >> >> dev_vdbg(mmc_dev(host->mmc), "Set clock to %uHz\n", ios->clock); >> >> @@ -496,7 +499,8 @@ static void omap_hsmmc_set_clock(struct omap_hsmmc_host *host) >> >> regval = OMAP_HSMMC_READ(host->base, SYSCTL); >> regval = regval & ~(CLKD_MASK | DTO_MASK); >> - regval = regval | (calc_divisor(host, ios) << 6) | (DTO << 16); >> + clkdiv = calc_divisor(host, ios); >> + regval = regval | (clkdiv << 6) | (DTO << 16); >> OMAP_HSMMC_WRITE(host->base, SYSCTL, regval); >> OMAP_HSMMC_WRITE(host->base, SYSCTL, >> OMAP_HSMMC_READ(host->base, SYSCTL) | ICE); >> @@ -507,6 +511,27 @@ static void omap_hsmmc_set_clock(struct omap_hsmmc_host *host) >> && time_before(jiffies, timeout)) >> cpu_relax(); >> >> + /* >> + * Enable High-Speed Support >> + * Pre-Requisites >> + * - Controller should support High-Speed-Enable Bit >> + * - Controller should not be using DDR Mode >> + * - Controller should advertise that it supports High Speed >> + * in capabilities register >> + * - MMC/SD clock coming out of controller > 25MHz >> + */ >> + if ((mmc_slot(host).features & HSMMC_HAS_HSPE_SUPPORT) && >> + (ios->timing != MMC_TIMING_UHS_DDR50) && >> + (OMAP_HSMMC_READ(host->base, CAPA) & HSS)) { >> + regval = OMAP_HSMMC_READ(host->base, HCTL); >> + if (clkdiv && (clk_get_rate(host->fclk)/clkdiv) > 25000000) > that clk rate could be a symbolic define. Ok will update as below and re-use #define OMAP_HSMMC_CLKOUT 25000000 > >> + regval |= HSPE; >> + else >> + regval &= ~HSPE; >> + >> + OMAP_HSMMC_WRITE(host->base, HCTL, regval); >> + } >> + >> omap_hsmmc_start_clock(host); >> } >> >> @@ -1700,6 +1725,9 @@ static struct omap_mmc_platform_data *of_get_hsmmc_pdata(struct device *dev) >> if (of_find_property(np, "ti,needs-special-reset", NULL)) >> pdata->slots[0].features |= HSMMC_HAS_UPDATED_RESET; >> >> + if (of_find_property(np, "ti,needs-special-hs-handling", NULL)) >> + pdata->slots[0].features |= HSMMC_HAS_HSPE_SUPPORT; > this could be of_property_read_bool(). Ok will change. >