[PATCH 5.15 27/83] mmc: moxart: fix 4-bit bus width and remove 8-bit bus width

Greg Kroah-Hartman
2022-10-03T08:52:19Z

From: Sergei Antonov <saproj@gmail.com>

commit 35ca91d1338ae158f6dcc0de5d1e86197924ffda upstream.

According to the datasheet [1] at page 377, 4-bit bus width is turned on by
bit 2 of the Bus Width Register. Thus the current bitmask is wrong: define
BUS_WIDTH_4 BIT(1)

BIT(1) does not work but BIT(2) works. This has been verified on real MOXA
hardware with FTSDC010 controller revision 1_6_0.

The corrected value of BUS_WIDTH_4 mask collides with: define BUS_WIDTH_8
BIT(2). Additionally, 8-bit bus width mode isn't supported according to the
datasheet, so let's remove the corresponding code.

[1]
https://bitbucket.org/Kasreyn/mkrom-uc7112lx/src/master/documents/FIC8120_DS_v1.2.pdf

Fixes: 1b66e94e6b99 ("mmc: moxart: Add MOXA ART SD/MMC driver")
Signed-off-by: Sergei Antonov <saproj@gmail.com>
Cc: Jonas Jensen <jonas.jensen@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220907205753.1577434-1-saproj@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/mmc/host/moxart-mmc.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)

--- a/drivers/mmc/host/moxart-mmc.c
+++ b/drivers/mmc/host/moxart-mmc.c
@@ -111,8 +111,8 @@
#define CLK_DIV_MASK 0x7f

/* REG_BUS_WIDTH */
-#define BUS_WIDTH_8 BIT(2)
-#define BUS_WIDTH_4 BIT(1)
+#define BUS_WIDTH_4_SUPPORT BIT(3)
+#define BUS_WIDTH_4 BIT(2)
#define BUS_WIDTH_1 BIT(0)

#define MMC_VDD_360 23
@@ -524,9 +524,6 @@ static void moxart_set_ios(struct mmc_ho
case MMC_BUS_WIDTH_4:
writel(BUS_WIDTH_4, host->base + REG_BUS_WIDTH);
break;
- case MMC_BUS_WIDTH_8:
- writel(BUS_WIDTH_8, host->base + REG_BUS_WIDTH);
- break;
default:
writel(BUS_WIDTH_1, host->base + REG_BUS_WIDTH);
break;
@@ -651,16 +648,8 @@ static int moxart_probe(struct platform_
dmaengine_slave_config(host->dma_chan_rx, &cfg);
}

- switch ((readl(host->base + REG_BUS_WIDTH) >> 3) & 3) {
- case 1:
+ if (readl(host->base + REG_BUS_WIDTH) & BUS_WIDTH_4_SUPPORT)
mmc->caps |= MMC_CAP_4_BIT_DATA;
- break;
- case 2:
- mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA;
- break;
- default:
- break;
- }

writel(0, host->base + REG_INTERRUPT_MASK);