| Message ID | 1528809280-31116-19-git-send-email-ludovic.Barre@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12 June 2018 at 15:14, Ludovic Barre <ludovic.Barre@st.com> wrote: > From: Ludovic Barre <ludovic.barre@st.com> > > This patch adds specific clock and power ios for stm32 sdmmc variant. > power ios: stm32 dedicated procedure must be done to perform power > off/on procedures. To power off, the sdmmc must be reset and set > to power cycle state before to disabling vqmmc. This drives low > SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK to prevent the Card from > being supplied through the signal lines. > To power on, set the SDMMC in power-off SDMMC_D[7:0], SDMMC_CMD > and SDMMC_CK are driven high. Then we can set the SDMMC to > Power-on state. > > clock ios: specific bits behavior: > -clock divider card_clk = mclk / (2 * clkdiv) > -ddr activation > -wide bus 1/4/8bits > -bus speed > -receive clock selection (in_ck/ck_in/fb_ck) > > Signed-off-by: Ludovic Barre <ludovic.barre@st.com> > --- > drivers/mmc/host/mmci.c | 112 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 112 insertions(+) > > diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c > index 86aef4f..af27a0a 100644 > --- a/drivers/mmc/host/mmci.c > +++ b/drivers/mmc/host/mmci.c > @@ -50,6 +50,10 @@ > > static unsigned int fmax = 515633; > > +static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, > + unsigned char power_mode, unsigned int pwr); > +static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired); > + > static struct variant_data variant_arm = { > .fifosize = 16 * 4, > .fifohalfsize = 8 * 4, > @@ -490,6 +494,114 @@ static void mmci_set_pwrreg(struct mmci_host *host, unsigned char power_mode, > mmci_write_pwrreg(host, pwr); > } > > +static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired) > +{ > + unsigned int clk = 0, ddr = 0; > + > + if (host->mmc->ios.timing == MMC_TIMING_MMC_DDR52 || > + host->mmc->ios.timing == MMC_TIMING_UHS_DDR50) > + ddr = MCI_STM32_CLK_DDR; > + > + /* > + * cclk = mclk / (2 * clkdiv) > + * clkdiv 0 => bypass > + * in ddr mode bypass is not possible > + */ > + if (desired) { > + if (desired >= host->mclk && !ddr) { > + host->cclk = host->mclk; > + } else { > + clk = DIV_ROUND_UP(host->mclk, 2 * desired); > + if (clk > MCI_STM32_CLK_CLKDIV_MSK) > + clk = MCI_STM32_CLK_CLKDIV_MSK; > + host->cclk = host->mclk / (2 * clk); > + } > + } > + > + if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) > + clk |= MCI_STM32_CLK_WIDEBUS_4; > + if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8) > + clk |= MCI_STM32_CLK_WIDEBUS_8; > + > + clk |= MCI_STM32_CLK_HWFCEN; > + clk |= host->clk_reg_add; > + clk |= ddr; > + > + /* > + * SDMMC_FBCK is selected when an external Delay Block is needed > + * with SDR104. > + */ > + if (host->mmc->ios.timing >= MMC_TIMING_UHS_SDR50) { > + clk |= MCI_STM32_CLK_BUSSPEED; > + if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104) { > + clk &= ~MCI_STM32_CLK_SEL_MSK; > + clk |= MCI_STM32_CLK_SELFBCK; > + } > + } > + > + mmci_write_clkreg(host, clk); > +} > + > +static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, > + unsigned char power_mode, unsigned int pwr) > +{ > + struct mmc_host *mmc = host->mmc; > + > + pwr |= host->pwr_reg_add; > + > + switch (power_mode) { > + case MMC_POWER_OFF: > + if (!IS_ERR(mmc->supply.vmmc)) > + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0); > + > + /* Only a reset could disable sdmmc */ > + reset_control_assert(host->rst); > + udelay(2); > + reset_control_deassert(host->rst); Could you please elaborate on what goes on here. Do you need to reset-the controller when powering off the card? > + > + /* default mask (probe) must be activated */ > + writel(MCI_IRQENABLE | host->variant->start_err, > + host->base + MMCIMASK0); The above seems like it could be made generic. There is no reason to keep IRQs enabled when the card is powered off. > + > + /* > + * Set the SDMMC in Power-cycle state before to disabling vqmmc. > + * This will make that the SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK > + * are driven low, to prevent the Card from being supplied > + * through the signal lines. > + */ > + mmci_write_pwrreg(host, MCI_STM32_PWR_CYC | pwr); > + > + if (!IS_ERR(host->mmc->supply.vqmmc) && host->vqmmc_enabled) { > + regulator_disable(host->mmc->supply.vqmmc); > + host->vqmmc_enabled = false; > + } > + break; > + case MMC_POWER_UP: > + if (!IS_ERR(mmc->supply.vmmc)) > + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, > + mmc->ios.vdd); > + break; > + case MMC_POWER_ON: > + if (!IS_ERR(host->mmc->supply.vqmmc) && !host->vqmmc_enabled) { > + if (regulator_enable(host->mmc->supply.vqmmc) < 0) > + dev_err(mmc_dev(host->mmc), > + "failed to enable vqmmc regulator\n"); > + else > + host->vqmmc_enabled = true; > + } > + > + /* > + * After a power-cycle state, we must set the SDMMC in > + * Power-off. The SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK are > + * driven high. Then we can set the SDMMC to Power-on state > + */ > + mmci_write_pwrreg(host, MCI_PWR_OFF | pwr); > + mdelay(1); > + mmci_write_pwrreg(host, MCI_PWR_ON | pwr); This looks odd. MMC_POWER_ON is the last power phase. For every single additional ios change (timing, clock, etc), you will hit this piece of code. In other words, there will be a mdelay(1) each time, which is probably not needed. > + break; > + } > +} > + > static void > mmci_request_end(struct mmci_host *host, struct mmc_request *mrq) > { > -- > 2.7.4 > Overall I am wondering if mmci_sdmmc_set_pwrreg() can be made generic inside the common mmci ->set_ios() functions instead. For example, the reset can be optional and checked with if(!IS_ERR(host->rst)) - and the others can probably be conditional based on a variant data. What do you think? Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index 86aef4f..af27a0a 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -50,6 +50,10 @@ static unsigned int fmax = 515633; +static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, + unsigned char power_mode, unsigned int pwr); +static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired); + static struct variant_data variant_arm = { .fifosize = 16 * 4, .fifohalfsize = 8 * 4, @@ -490,6 +494,114 @@ static void mmci_set_pwrreg(struct mmci_host *host, unsigned char power_mode, mmci_write_pwrreg(host, pwr); } +static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired) +{ + unsigned int clk = 0, ddr = 0; + + if (host->mmc->ios.timing == MMC_TIMING_MMC_DDR52 || + host->mmc->ios.timing == MMC_TIMING_UHS_DDR50) + ddr = MCI_STM32_CLK_DDR; + + /* + * cclk = mclk / (2 * clkdiv) + * clkdiv 0 => bypass + * in ddr mode bypass is not possible + */ + if (desired) { + if (desired >= host->mclk && !ddr) { + host->cclk = host->mclk; + } else { + clk = DIV_ROUND_UP(host->mclk, 2 * desired); + if (clk > MCI_STM32_CLK_CLKDIV_MSK) + clk = MCI_STM32_CLK_CLKDIV_MSK; + host->cclk = host->mclk / (2 * clk); + } + } + + if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) + clk |= MCI_STM32_CLK_WIDEBUS_4; + if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8) + clk |= MCI_STM32_CLK_WIDEBUS_8; + + clk |= MCI_STM32_CLK_HWFCEN; + clk |= host->clk_reg_add; + clk |= ddr; + + /* + * SDMMC_FBCK is selected when an external Delay Block is needed + * with SDR104. + */ + if (host->mmc->ios.timing >= MMC_TIMING_UHS_SDR50) { + clk |= MCI_STM32_CLK_BUSSPEED; + if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104) { + clk &= ~MCI_STM32_CLK_SEL_MSK; + clk |= MCI_STM32_CLK_SELFBCK; + } + } + + mmci_write_clkreg(host, clk); +} + +static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, + unsigned char power_mode, unsigned int pwr) +{ + struct mmc_host *mmc = host->mmc; + + pwr |= host->pwr_reg_add; + + switch (power_mode) { + case MMC_POWER_OFF: + if (!IS_ERR(mmc->supply.vmmc)) + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0); + + /* Only a reset could disable sdmmc */ + reset_control_assert(host->rst); + udelay(2); + reset_control_deassert(host->rst); + + /* default mask (probe) must be activated */ + writel(MCI_IRQENABLE | host->variant->start_err, + host->base + MMCIMASK0); + + /* + * Set the SDMMC in Power-cycle state before to disabling vqmmc. + * This will make that the SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK + * are driven low, to prevent the Card from being supplied + * through the signal lines. + */ + mmci_write_pwrreg(host, MCI_STM32_PWR_CYC | pwr); + + if (!IS_ERR(host->mmc->supply.vqmmc) && host->vqmmc_enabled) { + regulator_disable(host->mmc->supply.vqmmc); + host->vqmmc_enabled = false; + } + break; + case MMC_POWER_UP: + if (!IS_ERR(mmc->supply.vmmc)) + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, + mmc->ios.vdd); + break; + case MMC_POWER_ON: + if (!IS_ERR(host->mmc->supply.vqmmc) && !host->vqmmc_enabled) { + if (regulator_enable(host->mmc->supply.vqmmc) < 0) + dev_err(mmc_dev(host->mmc), + "failed to enable vqmmc regulator\n"); + else + host->vqmmc_enabled = true; + } + + /* + * After a power-cycle state, we must set the SDMMC in + * Power-off. The SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK are + * driven high. Then we can set the SDMMC to Power-on state + */ + mmci_write_pwrreg(host, MCI_PWR_OFF | pwr); + mdelay(1); + mmci_write_pwrreg(host, MCI_PWR_ON | pwr); + break; + } +} + static void mmci_request_end(struct mmci_host *host, struct mmc_request *mrq) {