Re: [PATCH 1/2] Support SD UHS for hikey-mainline-rebase

From: Shawn Lin
Date: Tue Jul 19 2016 - 21:10:19 EST

å 2016/7/19 20:28, Jinguojun åé:

On 2016/7/19 16:13, Jaehoon Chung wrote:

Removed the unnecessary CC'd.

On 07/19/2016 04:51 PM, Jin Guojun wrote:
From: j00226943 <j00226943@xxxxxxxxxxxxxxxxxxxx>

What is j00226943?

When you send the patch for dw_mmc controller, plz use the prefix "mmc: dw_mmc: ".

Two more changes:

Before we send cmd,we need to set CMD bit29 to
1 so that CMD and DATA sent to card through the HOLD Register,
This is the explication in synosys host:To meet the relatively
high Input Hold Time requirement for SDR12, SDR25, and other MMC
speed modes, you should program bit[29]use_hold_Reg of the CMD
register to 1'b1; the output data is then registered again in the
cclk_in_drv domain by using the Hold Register as shown in Path B
of Figure 10-8. However, for the higher speed modes of SDR104, SDR50
and DDR50, you can meet the much smaller Input Hold Time requirement
of 0.8ns by bypassing the Hold Register (Path A in Figure 10-8,
programming CMD.use_hold_reg = 1'b0) and then adding delay elements
on the output path as indicated

We have no tuning function in our drivers,so we must do the
Function piling when we init UHS card.

1.For hikey we cant support UHS for SD card in
2.I have no SDMMC_CMD_USE_HOLD_REG in Dw_mmc-k3.c

Sorry..this patch is NACK.
SDMMC_CMD_USE_HOLD_REG is already used by default in dw_mmc.c
Which kernel version did you use?

Signed-off-by: Jin Guojun <kid.jin@xxxxxxxxxxxxx>
drivers/mmc/host/dw_mmc-k3.c | 6 ++++++
drivers/mmc/host/dw_mmc.c | 2 ++
2 files changed, 8 insertions(+)

diff --git a/drivers/mmc/host/dw_mmc-k3.c b/drivers/mmc/host/dw_mmc-k3.c
index 63c2e2e..2cbfcc7 100644
--- a/drivers/mmc/host/dw_mmc-k3.c
+++ b/drivers/mmc/host/dw_mmc-k3.c
@@ -125,10 +125,16 @@ static void dw_mci_hi6220_set_ios(struct dw_mci *host, struct mmc_ios *ios)
host->bus_hz = clk_get_rate(host->biu_clk);

+static void dw_mci_hi6220_prepare_command(struct dw_mci *host, u32 *cmdr)
static const struct dw_mci_drv_data hi6220_data = {
.switch_voltage = dw_mci_hi6220_switch_voltage,
.set_ios = dw_mci_hi6220_set_ios,
.parse_dt = dw_mci_hi6220_parse_dt,
+ .prepare_command = dw_mci_hi6220_prepare_command,
Hi,thank you for your review

1.We do the prepare_command in dw_mci_prepare_command before we send CMD in dw_mmc.c

please clone Ulf's tree[0] and rebase your any patches on its next
branch, thanks.

[0] git://

2.I can find the same drivers in dw_mmc-exynos.c
3.For hikey we do the initialization from Dw_mmc-k3.c,so I need to do the prepare_command in hi6220 drivers

There is no "prepare_command" hooks.

Best Regards,
Jaehoon Chung

static const struct of_device_id dw_mci_k3_match[] = {
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 9dd1bd3..047e116 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1564,6 +1564,8 @@ static int dw_mci_execute_tuning(struct mmc_host *mmc, u32 opcode)

if (drv_data && drv_data->execute_tuning)
err = drv_data->execute_tuning(slot, opcode);
+ else
+ err = 0;
return err;


Best Regards
Shawn Lin