| Message ID | 20170906070507.26223-9-dirk.behme@de.bosch.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 09/06/2017 10:05 AM, Dirk Behme wrote: > From: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com> > > Reset register before starting transfer. > > Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com> > Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> > --- > drivers/spi/spi-sh-msiof.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c > index fdad8d852602..e8aebd406477 100644 > --- a/drivers/spi/spi-sh-msiof.c > +++ b/drivers/spi/spi-sh-msiof.c [...] > @@ -254,6 +256,25 @@ static irqreturn_t sh_msiof_spi_irq(int irq, void *data) > return IRQ_HANDLED; > } > > +static void sh_msiof_spi_reset_regs(struct sh_msiof_spi_priv *p) > +{ > + u32 mask = CTR_TXRST | CTR_RXRST; *const*? > + u32 data; > + int k; > + > + data = sh_msiof_read(p, CTR); > + data |= mask; > + Don't think empty line is needed here. > + sh_msiof_write(p, CTR, data); > + > + for (k = 100; k > 0; k--) { > + if (!(sh_msiof_read(p, CTR) & mask)) > + break; > + > + udelay(10); > + } > +} > + > static struct { > unsigned short div; > unsigned short brdv; [...] MBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Dirk, On Wed, Sep 6, 2017 at 9:05 AM, Dirk Behme <dirk.behme@de.bosch.com> wrote: > From: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com> > > Reset register before starting transfer. > > Signed-off-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com> > Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Why is this needed? What does it fix? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe from this list: send the line "unsubscribe linux-spi" 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/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c index fdad8d852602..e8aebd406477 100644 --- a/drivers/spi/spi-sh-msiof.c +++ b/drivers/spi/spi-sh-msiof.c @@ -130,6 +130,8 @@ struct sh_msiof_spi_priv { #define CTR_TFSE 0x00004000 /* Transmit Frame Sync Signal Output Enable */ #define CTR_TXE 0x00000200 /* Transmit Enable */ #define CTR_RXE 0x00000100 /* Receive Enable */ +#define CTR_TXRST 0x00000002 /* Transmit Reset */ +#define CTR_RXRST 0x00000001 /* Receive Reset */ /* FCTR */ #define FCTR_TFWM_MASK 0xe0000000 /* Transmit FIFO Watermark */ @@ -254,6 +256,25 @@ static irqreturn_t sh_msiof_spi_irq(int irq, void *data) return IRQ_HANDLED; } +static void sh_msiof_spi_reset_regs(struct sh_msiof_spi_priv *p) +{ + u32 mask = CTR_TXRST | CTR_RXRST; + u32 data; + int k; + + data = sh_msiof_read(p, CTR); + data |= mask; + + sh_msiof_write(p, CTR, data); + + for (k = 100; k > 0; k--) { + if (!(sh_msiof_read(p, CTR) & mask)) + break; + + udelay(10); + } +} + static struct { unsigned short div; unsigned short brdv; @@ -924,6 +945,9 @@ static int sh_msiof_transfer_one(struct spi_master *master, bool swab; int ret; + /* reset registers */ + sh_msiof_spi_reset_regs(p); + /* setup clocks (clock already enabled in chipselect()) */ if (!spi_controller_is_slave(p->master)) sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz);