| Message ID | 20210224055135.1509200-3-davidm@egauge.net (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | [1/4] wilc1000: Make SPI transfers work at 48MHz | expand |
David Mosberger-Tang <davidm@egauge.net> writes: > After a DMA write to the WILC chip, check for and report any errors. > > This is based on code from the wilc driver in the linux-at91 > repository. > > Signed-off-by: David Mosberger-Tang <davidm@egauge.net> > --- > drivers/net/wireless/microchip/wilc1000/spi.c | 50 ++++++++++++++++++- > 1 file changed, 49 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c > index fca34d1999ec..b0e096a03a28 100644 > --- a/drivers/net/wireless/microchip/wilc1000/spi.c > +++ b/drivers/net/wireless/microchip/wilc1000/spi.c > @@ -750,6 +750,51 @@ static int wilc_spi_write_reg(struct wilc *wilc, u32 addr, u32 data) > return 0; > } > > +static int spi_data_rsp(struct wilc *wilc, u8 cmd) > +{ > + struct spi_device *spi = to_spi_device(wilc->dev); > + int result, i; > + u8 rsp[4]; > + > + /* > + * The response to data packets is two bytes long. For > + * efficiency's sake, wilc_spi_write() wisely ignores the > + * responses for all packets but the final one. The downside > + * of that optimization is that when the final data packet is > + * short, we may receive (part of) the response to the > + * second-to-last packet before the one for the final packet. > + * To handle this, we always read 4 bytes and then search for > + * the last byte that contains the "Response Start" code (0xc > + * in the top 4 bits). We then know that this byte is the > + * first response byte of the final data packet. > + */ > + result = wilc_spi_rx(wilc, rsp, sizeof(rsp)); > + if (result) { > + dev_err(&spi->dev, "Failed bus error...\n"); > + return result; > + } > + > + for (i = sizeof(rsp) - 2; i >= 0; --i) > + if ((rsp[i] & 0xf0) == 0xc0) > + break; No magic numbers. Please create proper defines for these. > + if (i < 0) { > + dev_err(&spi->dev, > + "Data packet response missing (%02x %02x %02x %02x)\n", > + rsp[0], rsp[1], rsp[2], rsp[3]); > + return -1; > + } > + > + /* rsp[i] is the last response start byte */ > + > + if (rsp[i] != 0xc3 || rsp[i + 1] != 0x00) { Same here.
On Thu, 2021-02-25 at 10:27 +0200, Kalle Valo wrote: > David Mosberger-Tang <davidm@egauge.net> writes: > > + for (i = sizeof(rsp) - 2; i >= 0; --i) > > + if ((rsp[i] & 0xf0) == 0xc0) > > + break; > > No magic numbers. Please create proper defines for these.] > > + if (rsp[i] != 0xc3 || rsp[i + 1] != 0x00) { > > Same here. Good points. I'll change those, thanks. --david
diff --git a/drivers/net/wireless/microchip/wilc1000/spi.c b/drivers/net/wireless/microchip/wilc1000/spi.c index fca34d1999ec..b0e096a03a28 100644 --- a/drivers/net/wireless/microchip/wilc1000/spi.c +++ b/drivers/net/wireless/microchip/wilc1000/spi.c @@ -750,6 +750,51 @@ static int wilc_spi_write_reg(struct wilc *wilc, u32 addr, u32 data) return 0; } +static int spi_data_rsp(struct wilc *wilc, u8 cmd) +{ + struct spi_device *spi = to_spi_device(wilc->dev); + int result, i; + u8 rsp[4]; + + /* + * The response to data packets is two bytes long. For + * efficiency's sake, wilc_spi_write() wisely ignores the + * responses for all packets but the final one. The downside + * of that optimization is that when the final data packet is + * short, we may receive (part of) the response to the + * second-to-last packet before the one for the final packet. + * To handle this, we always read 4 bytes and then search for + * the last byte that contains the "Response Start" code (0xc + * in the top 4 bits). We then know that this byte is the + * first response byte of the final data packet. + */ + result = wilc_spi_rx(wilc, rsp, sizeof(rsp)); + if (result) { + dev_err(&spi->dev, "Failed bus error...\n"); + return result; + } + + for (i = sizeof(rsp) - 2; i >= 0; --i) + if ((rsp[i] & 0xf0) == 0xc0) + break; + + if (i < 0) { + dev_err(&spi->dev, + "Data packet response missing (%02x %02x %02x %02x)\n", + rsp[0], rsp[1], rsp[2], rsp[3]); + return -1; + } + + /* rsp[i] is the last response start byte */ + + if (rsp[i] != 0xc3 || rsp[i + 1] != 0x00) { + dev_err(&spi->dev, "Data response error (%02x %02x)\n", + rsp[i], rsp[i + 1]); + return -1; + } + return 0; +} + static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size) { struct spi_device *spi = to_spi_device(wilc->dev); @@ -777,7 +822,10 @@ static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size) return result; } - return 0; + /* + * Data response + */ + return spi_data_rsp(wilc, CMD_DMA_EXT_WRITE); } /********************************************
After a DMA write to the WILC chip, check for and report any errors. This is based on code from the wilc driver in the linux-at91 repository. Signed-off-by: David Mosberger-Tang <davidm@egauge.net> --- drivers/net/wireless/microchip/wilc1000/spi.c | 50 ++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-)