| Message ID | 20221202031330.94130-7-doug@schmorgal.com |
|---|---|
| State | New |
| Headers | show |
| Series | mmc: sdhci-pxav2: Add support for PXA168 | expand |
On 2/12/22 05:13, Doug Brown wrote: > 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> > --- > drivers/mmc/host/sdhci-pxav2.c | 49 ++++++++++++++++++++++++++++++++++ > 1 file changed, 49 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c > index 1f0c3028987a..912b2aad9f2e 100644 > --- a/drivers/mmc/host/sdhci-pxav2.c > +++ b/drivers/mmc/host/sdhci-pxav2.c > @@ -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" > @@ -43,6 +45,7 @@ > > struct sdhci_pxav2_host { > struct clk *clk_core; > + struct mmc_request *sdio_mrq; > }; > > static void pxav2_reset(struct sdhci_host *host, u8 mask) > @@ -93,6 +96,50 @@ 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)); > + > + 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; > + mmc_request_done(host->mmc, pxav2_host->sdio_mrq); > + pxav2_host->sdio_mrq = NULL; Pedantically, things should be finished before calling mmc_request_done() i.e. last 2 line the other way around pxav2_host->sdio_mrq = NULL; mmc_request_done(host->mmc, pxav2_host->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; > @@ -117,10 +164,12 @@ static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width) > 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_ops pxav2_sdhci_ops = {
diff --git a/drivers/mmc/host/sdhci-pxav2.c b/drivers/mmc/host/sdhci-pxav2.c index 1f0c3028987a..912b2aad9f2e 100644 --- a/drivers/mmc/host/sdhci-pxav2.c +++ b/drivers/mmc/host/sdhci-pxav2.c @@ -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" @@ -43,6 +45,7 @@ struct sdhci_pxav2_host { struct clk *clk_core; + struct mmc_request *sdio_mrq; }; static void pxav2_reset(struct sdhci_host *host, u8 mask) @@ -93,6 +96,50 @@ 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)); + + 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; + mmc_request_done(host->mmc, pxav2_host->sdio_mrq); + pxav2_host->sdio_mrq = NULL; + } + + 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; @@ -117,10 +164,12 @@ static void pxav2_mmc_set_bus_width(struct sdhci_host *host, int width) 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_ops pxav2_sdhci_ops = {
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> --- drivers/mmc/host/sdhci-pxav2.c | 49 ++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+)