diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/mmc/host/meson-gx-mmc.c | 73 |
1 files changed, 70 insertions, 3 deletions
diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c index acdc5520d02c..c5a8af4ca76b 100644 --- a/drivers/mmc/host/meson-gx-mmc.c +++ b/drivers/mmc/host/meson-gx-mmc.c @@ -488,6 +488,61 @@ static int meson_mmc_clk_init(struct meson_host *host) return clk_prepare_enable(host->mmc_clk); } +static void meson_mmc_disable_resampling(struct meson_host *host) +{ + unsigned int val = readl(host->regs + host->data->adjust); + + val &= ~ADJUST_ADJ_EN; + writel(val, host->regs + host->data->adjust); +} + +static void meson_mmc_reset_resampling(struct meson_host *host) +{ + unsigned int val; + + meson_mmc_disable_resampling(host); + + val = readl(host->regs + host->data->adjust); + val &= ~ADJUST_ADJ_DELAY_MASK; + writel(val, host->regs + host->data->adjust); +} + +static int meson_mmc_resampling_tuning(struct mmc_host *mmc, u32 opcode) +{ + struct meson_host *host = mmc_priv(mmc); + unsigned int val, dly, max_dly, i; + int ret; + + /* Resampling is done using the source clock */ + max_dly = DIV_ROUND_UP(clk_get_rate(host->mux_clk), + clk_get_rate(host->mmc_clk)); + + val = readl(host->regs + host->data->adjust); + val |= ADJUST_ADJ_EN; + writel(val, host->regs + host->data->adjust); + + if (mmc->doing_retune) + dly = FIELD_GET(ADJUST_ADJ_DELAY_MASK, val) + 1; + else + dly = 0; + + for (i = 0; i < max_dly; i++) { + val &= ~ADJUST_ADJ_DELAY_MASK; + val |= FIELD_PREP(ADJUST_ADJ_DELAY_MASK, (dly + i) % max_dly); + writel(val, host->regs + host->data->adjust); + + ret = mmc_send_tuning(mmc, opcode, NULL); + if (!ret) { + dev_dbg(mmc_dev(mmc), "resampling delay: %u\n", + (dly + i) % max_dly); + return 0; + } + } + + meson_mmc_reset_resampling(host); + return -EIO; +} + static int meson_mmc_prepare_ios_clock(struct meson_host *host, struct mmc_ios *ios) { @@ -507,6 +562,19 @@ static int meson_mmc_prepare_ios_clock(struct meson_host *host, return meson_mmc_clk_set(host, ios->clock, ddr); } +static void meson_mmc_check_resampling(struct meson_host *host, + struct mmc_ios *ios) +{ + switch (ios->timing) { + case MMC_TIMING_LEGACY: + case MMC_TIMING_MMC_HS: + case MMC_TIMING_SD_HS: + case MMC_TIMING_MMC_DDR52: + meson_mmc_disable_resampling(host); + break; + } +} + static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) { struct meson_host *host = mmc_priv(mmc); @@ -533,9 +601,6 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) if (!IS_ERR(mmc->supply.vmmc)) mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd); - /* disable signal resampling */ - writel(0, host->regs + host->data->adjust); - break; case MMC_POWER_ON: @@ -574,6 +639,7 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) val |= FIELD_PREP(CFG_BUS_WIDTH_MASK, bus_width); writel(val, host->regs + SD_EMMC_CFG); + meson_mmc_check_resampling(host, ios); err = meson_mmc_prepare_ios_clock(host, ios); if (err) dev_err(host->dev, "Failed to set clock: %d\n,", err); @@ -963,6 +1029,7 @@ static const struct mmc_host_ops meson_mmc_ops = { .get_cd = meson_mmc_get_cd, .pre_req = meson_mmc_pre_req, .post_req = meson_mmc_post_req, + .execute_tuning = meson_mmc_resampling_tuning, .card_busy = meson_mmc_card_busy, .start_signal_voltage_switch = meson_mmc_voltage_switch, }; |