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mmc: litex_mmc: Set width from linux request

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Previously, the litex_mmc driver force the 4 bits bus width.
This means that the gateware with 1 bit bus width is not fit.
However, litesdcard does support setting bus width, which
make the 1 bit bus width gateware possible to be used.

Add logic for setting bus width in the set_ios() function.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>
This commit is contained in:
Inochi Amaoto 2026-06-29 15:25:07 +08:00 committed by Ulf Hansson
parent f13ca4f2b0
commit 33b55cd1d3
1 changed files with 29 additions and 7 deletions
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36
drivers/mmc/host/litex_mmc.c
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@ -28,6 +28,7 @@
#define LITEX_PHY_CLOCKERDIV 0x04
#define LITEX_PHY_INITIALIZE 0x08
#define LITEX_PHY_WRITESTATUS 0x0C
#define LITEX_PHY_SETTINGS 0x18
#define LITEX_CORE_CMDARG 0x00
#define LITEX_CORE_CMDCMD 0x04
#define LITEX_CORE_CMDSND 0x08
@ -71,6 +72,10 @@
#define SD_INIT_DELAY_US 1000
#define SD_INIT_CLK_HZ 400000
#define SD_PHY_SPEED_1X 0
#define SD_PHY_SPEED_4X 1
#define SD_PHY_SPEED_8X 2
#define SDIRQ_CARD_DETECT 1
#define SDIRQ_SD_TO_MEM_DONE 2
#define SDIRQ_MEM_TO_SD_DONE 4
@ -95,6 +100,8 @@ struct litex_mmc_host {
unsigned int ref_clk;
unsigned int sd_clk;
u8 width;
u32 resp[4];
u16 rca;
@ -450,6 +457,24 @@ static void litex_mmc_setclk(struct litex_mmc_host *host, unsigned int freq)
static void litex_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct litex_mmc_host *host = mmc_priv(mmc);
unsigned int bus_width = SD_PHY_SPEED_1X;
switch (ios->bus_width) {
case MMC_BUS_WIDTH_1:
bus_width = SD_PHY_SPEED_1X;
break;
case MMC_BUS_WIDTH_4:
bus_width = SD_PHY_SPEED_4X;
break;
case MMC_BUS_WIDTH_8:
bus_width = SD_PHY_SPEED_8X;
break;
}
if (host->width != ios->bus_width) {
litex_write8(host->sdphy + LITEX_PHY_SETTINGS, bus_width);
host->width = ios->bus_width;
}
/*
* The SD specification requires at least 74 idle clocks before CMD0.
@ -462,13 +487,6 @@ static void litex_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
return;
}
/*
* NOTE: Ignore any ios->bus_width updates; they occur right after
* the mmc core sends its own acmd6 bus-width change notification,
* which is redundant since we snoop on the command flow and inject
* an early acmd6 before the first data transfer command is sent!
*/
/* Update sd_clk */
if (ios->clock != host->sd_clk)
litex_mmc_setclk(host, ios->clock);
@ -554,6 +572,7 @@ static int litex_mmc_probe(struct platform_device *pdev)
*/
host->is_bus_width_set = false;
host->app_cmd = false;
host->width = MMC_BUS_WIDTH_1;
/* LiteSDCard can support 64-bit DMA addressing */
ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
@ -586,6 +605,9 @@ static int litex_mmc_probe(struct platform_device *pdev)
litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0);
litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0);
/* Ensure the litex is at bus width x1 */
litex_write8(host->sdphy + LITEX_PHY_SETTINGS, SD_PHY_SPEED_1X);
init_completion(&host->cmd_done);
ret = litex_mmc_irq_init(pdev, host);
if (ret)