Add hardware tuning function instead of software tuning because O2/Bayhub
SD host controller support hardware tuning.
Signed-off-by: ernest.zhang <ernest.zh...@bayhubtech.com>
---
Changes in V7:
Move V6 change item 1 to a seperate patch.
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 | 4 +-
2 files changed, 84 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c
b/drivers/mmc/host/sdhci-pci-o2micro.c
index 94cf3cd75dd3..7747e8ba2e3d 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 bcea179a8d70..1b3fbd9bd5c5 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);
--
2.17.1
