| Message ID | 1398116898-31478-1-git-send-email-srinivas.kandagatla@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Mon, Apr 21, 2014 at 10:48:18PM +0100, srinivas.kandagatla@linaro.org wrote: > From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> > > This patch adds write delay parameter required after each write to controller > registers on some of the SOCs like Qualcomm ones. The delay parameter will > provide information on how many clock cycle delay required after each write. > > Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> > --- > drivers/mmc/host/mmci.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c > index 4f8d0ba..86bf330 100644 > --- a/drivers/mmc/host/mmci.c > +++ b/drivers/mmc/host/mmci.c > @@ -55,6 +55,8 @@ static unsigned int fmax = 515633; > * is asserted (likewise for RX) > * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY > * is asserted (likewise for RX) > + * @reg_write_delay: delay in number of clock cycles required after each write > + * to controller registers. > * @sdio: variant supports SDIO > * @st_clkdiv: true if using a ST-specific clock divider algorithm > * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register > @@ -72,6 +74,7 @@ struct variant_data { > unsigned int datalength_bits; > unsigned int fifosize; > unsigned int fifohalfsize; > + unsigned int reg_write_delay; > bool sdio; > bool st_clkdiv; > bool blksz_datactrl16; > @@ -178,7 +181,12 @@ static inline u32 mmci_readl(struct mmci_host *host, u32 off) > > static inline void mmci_writel(struct mmci_host *host, u32 data, u32 off) > { > + struct variant_data *var = host->variant; > + > writel(data, host->base + off); > + > + if (var->reg_write_delay && host->mclk) > + udelay(1 + ((var->reg_write_delay * USEC_PER_SEC)/host->mclk)); looks like this should be quirk flag instead of a write delay... No strong feelings though, but it looks like the following would be better, perhaps: if (host_is_qualcom(host)) udelay(1 + ((3 * USEC_PER_SEC)/host->mclk));
Thanks Felipe, On 21/04/14 23:08, Felipe Balbi wrote: >> + if (var->reg_write_delay && host->mclk) >> >+ udelay(1 + ((var->reg_write_delay * USEC_PER_SEC)/host->mclk)); > looks like this should be quirk flag instead of a write delay... No > strong feelings though, but it looks like the following would be better, > perhaps: > > if (host_is_qualcom(host)) > udelay(1 + ((3 * USEC_PER_SEC)/host->mclk)); Am ok with your proposal. I was wondering if someone else might need it in future. If not I could change it as you suggested. Thanks, srini > > -- -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index 4f8d0ba..86bf330 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -55,6 +55,8 @@ static unsigned int fmax = 515633; * is asserted (likewise for RX) * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY * is asserted (likewise for RX) + * @reg_write_delay: delay in number of clock cycles required after each write + * to controller registers. * @sdio: variant supports SDIO * @st_clkdiv: true if using a ST-specific clock divider algorithm * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register @@ -72,6 +74,7 @@ struct variant_data { unsigned int datalength_bits; unsigned int fifosize; unsigned int fifohalfsize; + unsigned int reg_write_delay; bool sdio; bool st_clkdiv; bool blksz_datactrl16; @@ -178,7 +181,12 @@ static inline u32 mmci_readl(struct mmci_host *host, u32 off) static inline void mmci_writel(struct mmci_host *host, u32 data, u32 off) { + struct variant_data *var = host->variant; + writel(data, host->base + off); + + if (var->reg_write_delay && host->mclk) + udelay(1 + ((var->reg_write_delay * USEC_PER_SEC)/host->mclk)); } static int mmci_card_busy(struct mmc_host *mmc)