Re: [RFC PATCH 08/11] mci: Add sunxi-mmc driver

[Sascha Hauer <sha@pengutronix.de>]

On Thu, May 18, 2023 at 09:26:56PM +0200, Ahmad Fatoum wrote:
> On 11.05.23 01:37, Jules Maselbas wrote:
> > This driver is adapted from different sources: Linux, u-boot and p-boot.
> > The latter, p-boot (forked from u-boot), is a bootloader for pinephones.
> > 
> > It currently only support PIO xfer but could be further improved to also
> > support DMA xfer. This driver is split in three source file so it can be
> > used by PBL and barebox proper.
> > ---
> >  drivers/mci/Kconfig            |   6 +
> >  drivers/mci/Makefile           |   2 +
> >  drivers/mci/sunxi-mmc-common.c | 259 +++++++++++++++++++++++++++++++++
> >  drivers/mci/sunxi-mmc-pbl.c    |  81 +++++++++++
> >  drivers/mci/sunxi-mmc.c        | 173 ++++++++++++++++++++++
> >  drivers/mci/sunxi-mmc.h        | 225 ++++++++++++++++++++++++++++
> >  include/mach/sunxi/xload.h     |  12 ++
> >  7 files changed, 758 insertions(+)
> >  create mode 100644 drivers/mci/sunxi-mmc-common.c
> >  create mode 100644 drivers/mci/sunxi-mmc-pbl.c
> >  create mode 100644 drivers/mci/sunxi-mmc.c
> >  create mode 100644 drivers/mci/sunxi-mmc.h
> >  create mode 100644 include/mach/sunxi/xload.h
> > 
> > diff --git a/drivers/mci/Kconfig b/drivers/mci/Kconfig
> > index bbdca67e9d..c1903b6c90 100644
> > --- a/drivers/mci/Kconfig
> > +++ b/drivers/mci/Kconfig
> > @@ -72,6 +72,12 @@ config MCI_DW_PIO
> >  	help
> >  	  Use PIO mode (instead of IDMAC) in DW MMC driver.
> >  
> > +config MCI_SUNXI_SMHC
> > +	bool "Allwinner SD-MMC Memory Card Host Controller"
> > +	help
> > +	  Enable support for the Allwinner SD-MMC Memory Card Host Controller,
> > +	  his provides host support for SD and MMC interfaces, in PIO mode.
> 
> This
> 
> > +
> >  config MCI_MXS
> >  	bool "i.MX23/i.MX28"
> >  	depends on ARCH_MXS
> > diff --git a/drivers/mci/Makefile b/drivers/mci/Makefile
> > index e3dc5ad8ae..c17cd41db1 100644
> > --- a/drivers/mci/Makefile
> > +++ b/drivers/mci/Makefile
> > @@ -20,4 +20,6 @@ obj-$(CONFIG_MCI_SPI)		+= mci_spi.o
> >  obj-$(CONFIG_MCI_DW)		+= dw_mmc.o
> >  obj-$(CONFIG_MCI_MMCI)		+= mmci.o
> >  obj-$(CONFIG_MCI_STM32_SDMMC2)	+= stm32_sdmmc2.o
> > +obj-$(CONFIG_MCI_SUNXI_SMHC)	+= sunxi-mmc.o
> > +pbl-$(CONFIG_MCI_SUNXI_SMHC)	+= sunxi-mmc-pbl.o
> >  obj-pbl-$(CONFIG_MCI_SDHCI)	+= sdhci.o
> > diff --git a/drivers/mci/sunxi-mmc-common.c b/drivers/mci/sunxi-mmc-common.c
> > new file mode 100644
> > index 0000000000..845078805b
> > --- /dev/null
> > +++ b/drivers/mci/sunxi-mmc-common.c
> > @@ -0,0 +1,259 @@
> > +#include "sunxi-mmc.h"
> > +
> > +static int sdxc_read_data_pio(struct sunxi_mmc_host *host, struct mci_data *data);
> > +static int sdxc_write_data_pio(struct sunxi_mmc_host *host, struct mci_data *data);
> > +static int sunxi_mmc_send_cmd(struct sunxi_mmc_host *host, struct mci_cmd *cmd, struct mci_data *data, const char **why);
> > +static int sunxi_mmc_set_ios(struct sunxi_mmc_host *host, struct mci_ios *ios);
> > +static void sunxi_mmc_init(struct sunxi_mmc_host *host);
> > +
> > +static int sdxc_read_data_pio(struct sunxi_mmc_host *host, struct mci_data *data)
> > +{
> > +	size_t i, len = data->blocks * data->blocksize;
> > +	u8 *dst = data->dest;
> > +	u32 reg;
> > +
> > +	sdxc_writel(host, SDXC_REG_GCTRL, SDXC_GCTRL_ACCESS_BY_AHB);
> > +
> > +	for (i = 0; i < len; i += 4) {
> > +		if (wait_on_timeout(2000 * MSECOND, !sdxc_is_fifo_empty(host)))
> 
> This can add up to 8 seconds. Just use is_timeout directly?
> 
> > +			return -ETIMEDOUT;

It will return -ETIMEDOUT after two seconds at maximum.

Sascha

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