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mmc: sdhci: Add support for O2 hardware tuning 

Add hardware tuning function instead of software tuning because O2/Bayhub
SD host controller support hardware tuning.

Signed-off-by: ernest.zhang <ernest.zhang@bayhubtech.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
hifive-unleashed-5.1
ernest.zhang 2018-07-16 14:26:54 +08:00 committed by Ulf Hansson
parent 6663c419a0
commit 0086fc217d
2 changed files with 84 additions and 1 deletions
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81
drivers/mmc/host/sdhci-pci-o2micro.c
View File

@ -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 */

4
drivers/mmc/host/sdhci.c
View File

@ -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);