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mmc: sdhci-pxav2: add SDIO card IRQ workaround for PXA168 V1 controller

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The PXA168 has a documented silicon bug that causes SDIO card IRQs to be
missed. Implement the first half of the suggested workaround, which
involves resetting the data port logic and issuing a dummy CMD0 to
restart the clock.

Signed-off-by: Doug Brown <doug@schmorgal.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20230116194401.20372-7-doug@schmorgal.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Doug Brown 2023-01-16 11:43:59 -08:00 committed by Ulf Hansson
parent e41c48b4bc
commit 24552ccb4f
1 changed files with 55 additions and 1 deletions
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56
drivers/mmc/host/sdhci-pxav2.c
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@ -20,6 +20,8 @@
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/mmc/sdio.h>
#include <linux/mmc/mmc.h>
#include "sdhci.h"
#include "sdhci-pltfm.h"
@ -41,6 +43,10 @@
#define MMC_CARD 0x1000
#define MMC_WIDTH 0x0100
struct sdhci_pxav2_host {
struct mmc_request *sdio_mrq;
};
static void pxav2_reset(struct sdhci_host *host, u8 mask)
{
struct platform_device *pdev = to_platform_device(mmc_dev(host->mmc));
@ -89,6 +95,52 @@ static u16 pxav1_readw(struct sdhci_host *host, int reg)
return readw(host->ioaddr + reg);
}
static u32 pxav1_irq(struct sdhci_host *host, u32 intmask)
{
struct sdhci_pxav2_host *pxav2_host = sdhci_pltfm_priv(sdhci_priv(host));
struct mmc_request *sdio_mrq;
if (pxav2_host->sdio_mrq && (intmask & SDHCI_INT_CMD_MASK)) {
/* The dummy CMD0 for the SDIO workaround just completed */
sdhci_writel(host, intmask & SDHCI_INT_CMD_MASK, SDHCI_INT_STATUS);
intmask &= ~SDHCI_INT_CMD_MASK;
sdio_mrq = pxav2_host->sdio_mrq;
pxav2_host->sdio_mrq = NULL;
mmc_request_done(host->mmc, sdio_mrq);
}
return intmask;
}
static void pxav1_request_done(struct sdhci_host *host, struct mmc_request *mrq)
{
u16 tmp;
struct sdhci_pxav2_host *pxav2_host;
/* If this is an SDIO command, perform errata workaround for silicon bug */
if (mrq->cmd && !mrq->cmd->error &&
(mrq->cmd->opcode == SD_IO_RW_DIRECT ||
mrq->cmd->opcode == SD_IO_RW_EXTENDED)) {
/* Reset data port */
tmp = readw(host->ioaddr + SDHCI_TIMEOUT_CONTROL);
tmp |= 0x400;
writew(tmp, host->ioaddr + SDHCI_TIMEOUT_CONTROL);
/* Clock is now stopped, so restart it by sending a dummy CMD0 */
pxav2_host = sdhci_pltfm_priv(sdhci_priv(host));
pxav2_host->sdio_mrq = mrq;
sdhci_writel(host, 0, SDHCI_ARGUMENT);
sdhci_writew(host, 0, SDHCI_TRANSFER_MODE);
sdhci_writew(host, SDHCI_MAKE_CMD(MMC_GO_IDLE_STATE, SDHCI_CMD_RESP_NONE),
SDHCI_COMMAND);
/* Don't finish this request until the dummy CMD0 finishes */
return;
}
mmc_request_done(host->mmc, mrq);
}
static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width)
{
u8 ctrl;
@ -118,10 +170,12 @@ struct sdhci_pxa_variant {
static const struct sdhci_ops pxav1_sdhci_ops = {
.read_w = pxav1_readw,
.set_clock = sdhci_set_clock,
.irq = pxav1_irq,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.set_bus_width = pxav2_mmc_set_bus_width,
.reset = pxav2_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,
.request_done = pxav1_request_done,
};
static const struct sdhci_pxa_variant __maybe_unused pxav1_variant = {
@ -193,7 +247,7 @@ static int sdhci_pxav2_probe(struct platform_device *pdev)
int ret;
struct clk *clk, *clk_core;
host = sdhci_pltfm_init(pdev, NULL, 0);
host = sdhci_pltfm_init(pdev, NULL, sizeof(struct sdhci_pxav2_host));
if (IS_ERR(host))
return PTR_ERR(host);