Add hardware tuning function instead of software tuning because O2/Bayhub SD host controller support hardware tuning.
Signed-off-by: ernest.zhang <[email protected]> --- Changes in V6: 1. From module 'sdhci' export the symbols 'sdhci_start_tuning', 'sdhci_end_tuning','sdhci_send_tuning' and 'sdhci_reset_tuning'. 2. Remove local tuning related functions in sdhci-pci-o2-micro.c instead of above function exported in sdhci module. 3. Remove unneeded braces in function sdhci_set_transfer_mode. 4. Move change log to correct place. Changes in V5: In function sdhci_o2_send_tuning, mrq.data should set to NULL for cmd.data has been set to NULL. Changes in V4: Patch V3 delete register SDHCI_TRANSFER_MODE write operation before send hardware tuning command in function sdhci_o2_send_tuning. This is a mistake. The write operation is essential for tuning command. Add it back. Changes in V3: Rebase the patch on the mmc tree 'next' branch. Changes in V2: Modify code format, and delete unused code path. Changes in V1: Add many functions to execute hardware tuning for eMMC 1.8V HS200 mode, the hardware tuning procedure is based on O2/Bayhub hardware tuning spec. --- drivers/mmc/host/sdhci-pci-o2micro.c | 81 ++++++++++++++++++++++++++++++++++++ drivers/mmc/host/sdhci.c | 16 ++++--- drivers/mmc/host/sdhci.h | 5 +++ 3 files changed, 97 insertions(+), 5 deletions(-) diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c index 94cf3cd..7747e8b 100644 --- a/drivers/mmc/host/sdhci-pci-o2micro.c +++ b/drivers/mmc/host/sdhci-pci-o2micro.c @@ -17,6 +17,9 @@ */ #include <linux/pci.h> +#include <linux/mmc/host.h> +#include <linux/mmc/mmc.h> +#include <linux/delay.h> #include "sdhci.h" #include "sdhci-pci.h" @@ -55,6 +58,82 @@ #define O2_SD_VENDOR_SETTING 0x110 #define O2_SD_VENDOR_SETTING2 0x1C8 +#define O2_SD_HW_TUNING_DISABLE BIT(4) + +static void sdhci_o2_set_tuning_mode(struct sdhci_host *host) +{ + u16 reg; + + /* enable hardware tuning */ + reg = sdhci_readw(host, O2_SD_VENDOR_SETTING); + reg &= ~O2_SD_HW_TUNING_DISABLE; + sdhci_writew(host, reg, O2_SD_VENDOR_SETTING); +} + +static void __sdhci_o2_execute_tuning(struct sdhci_host *host, u32 opcode) +{ + int i; + + sdhci_send_tuning(host, MMC_SEND_TUNING_BLOCK_HS200); + + for (i = 0; i < 150; i++) { + u16 ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); + + if (!(ctrl & SDHCI_CTRL_EXEC_TUNING)) { + if (ctrl & SDHCI_CTRL_TUNED_CLK) { + host->tuning_done = true; + return; + } + pr_warn("%s: HW tuning failed !\n", + mmc_hostname(host->mmc)); + break; + } + + mdelay(1); + } + + pr_info("%s: Tuning failed, falling back to fixed sampling clock\n", + mmc_hostname(host->mmc)); + sdhci_reset_tuning(host); +} + +static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode) +{ + struct sdhci_host *host = mmc_priv(mmc); + int current_bus_width = 0; + + /* + * This handler only implements the eMMC tuning that is specific to + * this controller. Fall back to the standard method for other TIMING. + */ + if (host->timing != MMC_TIMING_MMC_HS200) + return sdhci_execute_tuning(mmc, opcode); + + if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200)) + return -EINVAL; + + /* + * o2 sdhci host didn't support 8bit emmc tuning + */ + if (mmc->ios.bus_width == MMC_BUS_WIDTH_8) { + current_bus_width = mmc->ios.bus_width; + sdhci_set_bus_width(host, MMC_BUS_WIDTH_4); + } + + sdhci_o2_set_tuning_mode(host); + + sdhci_start_tuning(host); + + __sdhci_o2_execute_tuning(host, opcode); + + sdhci_end_tuning(host); + + if (current_bus_width == MMC_BUS_WIDTH_8) + sdhci_set_bus_width(host, current_bus_width); + + host->flags &= ~SDHCI_HS400_TUNING; + return 0; +} static void o2_pci_set_baseclk(struct sdhci_pci_chip *chip, u32 value) { @@ -215,6 +294,8 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot) } } + host->mmc_host_ops.execute_tuning = sdhci_o2_execute_tuning; + if (chip->pdev->device != PCI_DEVICE_ID_O2_FUJIN2) break; /* set dll watch dog timer */ diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 1c828e0..4f3e3c2 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1029,7 +1029,9 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host, if (data == NULL) { if (host->quirks2 & SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD) { - sdhci_writew(host, 0x0, SDHCI_TRANSFER_MODE); + /* must not clear SDHCI_TRANSFER_MODE when tuning */ + if (cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) + sdhci_writew(host, 0x0, SDHCI_TRANSFER_MODE); } else { /* clear Auto CMD settings for no data CMDs */ mode = sdhci_readw(host, SDHCI_TRANSFER_MODE); @@ -2103,7 +2105,7 @@ static int sdhci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios) return 0; } -static void sdhci_start_tuning(struct sdhci_host *host) +void sdhci_start_tuning(struct sdhci_host *host) { u16 ctrl; @@ -2126,14 +2128,16 @@ static void sdhci_start_tuning(struct sdhci_host *host) sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_INT_ENABLE); sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_SIGNAL_ENABLE); } +EXPORT_SYMBOL_GPL(sdhci_start_tuning); -static void sdhci_end_tuning(struct sdhci_host *host) +void sdhci_end_tuning(struct sdhci_host *host) { sdhci_writel(host, host->ier, SDHCI_INT_ENABLE); sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE); } +EXPORT_SYMBOL_GPL(sdhci_end_tuning); -static void sdhci_reset_tuning(struct sdhci_host *host) +void sdhci_reset_tuning(struct sdhci_host *host) { u16 ctrl; @@ -2142,6 +2146,7 @@ static void sdhci_reset_tuning(struct sdhci_host *host) ctrl &= ~SDHCI_CTRL_EXEC_TUNING; sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2); } +EXPORT_SYMBOL_GPL(sdhci_reset_tuning); static void sdhci_abort_tuning(struct sdhci_host *host, u32 opcode) { @@ -2162,7 +2167,7 @@ static void sdhci_abort_tuning(struct sdhci_host *host, u32 opcode) * interrupt setup is different to other commands and there is no timeout * interrupt so special handling is needed. */ -static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode) +void sdhci_send_tuning(struct sdhci_host *host, u32 opcode) { struct mmc_host *mmc = host->mmc; struct mmc_command cmd = {}; @@ -2212,6 +2217,7 @@ static void sdhci_send_tuning(struct sdhci_host *host, u32 opcode) msecs_to_jiffies(50)); } +EXPORT_SYMBOL_GPL(sdhci_send_tuning); static void __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode) { diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 23966f8..2a09c0a 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -748,4 +748,9 @@ bool sdhci_cqe_irq(struct sdhci_host *host, u32 intmask, int *cmd_error, void sdhci_dumpregs(struct sdhci_host *host); +void sdhci_start_tuning(struct sdhci_host *host); +void sdhci_end_tuning(struct sdhci_host *host); +void sdhci_send_tuning(struct sdhci_host *host, u32 opcode); +void sdhci_reset_tuning(struct sdhci_host *host); + #endif /* __SDHCI_HW_H */ -- 2.7.4
