diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/soc/rockchip/rk3288/spi.c | 182 |
1 files changed, 122 insertions, 60 deletions
diff --git a/src/soc/rockchip/rk3288/spi.c b/src/soc/rockchip/rk3288/spi.c index a74d423a62..796107e071 100644 --- a/src/soc/rockchip/rk3288/spi.c +++ b/src/soc/rockchip/rk3288/spi.c @@ -171,77 +171,121 @@ static int rockchip_spi_wait_till_not_busy(struct rockchip_spi *regs) return -1; } -int spi_xfer(struct spi_slave *slave, const void *dout, unsigned int sout, - void *din, unsigned int sin) +static void set_tmod(struct rockchip_spi *regs, unsigned int tmod) +{ + clrsetbits_le32(®s->ctrlr0, SPI_TMOD_MASK << SPI_TMOD_OFFSET, + tmod << SPI_TMOD_OFFSET); +} + +static void set_transfer_mode(struct rockchip_spi *regs, + unsigned int sout, unsigned int sin) +{ + if (!sin && !sout) + return; + else if (sin && sout) + set_tmod(regs, SPI_TMOD_TR); /* tx and rx */ + else if (!sin) + set_tmod(regs, SPI_TMOD_TO); /* tx only */ + else if (!sout) + set_tmod(regs, SPI_TMOD_RO); /* rx only */ +} + +/* returns 0 to indicate success, <0 otherwise */ +static int do_xfer(struct spi_slave *slave, const void *dout, + unsigned int *bytes_out, void *din, unsigned int *bytes_in) { - unsigned int len; - unsigned int bytes_remaining; - uint8_t *p; struct rockchip_spi *regs = to_rockchip_spi(slave)->regs; + uint8_t *in_buf = din; + uint8_t *out_buf = (uint8_t *)dout; + unsigned int min_xfer; + + if (*bytes_out == 0) + min_xfer = *bytes_in; + else if (*bytes_in == 0) + min_xfer = *bytes_out; + else + min_xfer = MIN(*bytes_in, *bytes_out); - if (dout) { - len = sout; - p = (uint8_t *) dout; - bytes_remaining = len; - writel(0, ®s->spienr); /*disable spi */ - writel(len - 1, ®s->ctrlr1); /*wrtie len */ - - /*tx only */ - clrsetbits_le32(®s->ctrlr0, SPI_TMOD_MASK << SPI_TMOD_OFFSET, - SPI_TMOD_TO << SPI_TMOD_OFFSET); - writel(1, ®s->spienr);/*enable spi */ - while (bytes_remaining) { - if ((readl(®s->txflr) & 0x3f) < SPI_FIFO_DEPTH) { - writel(*p++, ®s->txdr); - bytes_remaining--; - } + while (min_xfer) { + uint32_t sr = readl(®s->sr); + int xferred = 0; /* in either (or both) directions */ + + if (*bytes_out && !(sr & SR_TF_FULL)) { + writel(*out_buf, ®s->txdr); + out_buf++; + *bytes_out -= 1; + xferred = 1; } - if (rockchip_spi_wait_till_not_busy(regs)) - return -1; - } - if (din) { - len = sin; - p = (uint8_t *) din; - writel(0, ®s->spienr); /*disable spi */ - writel(len - 1, ®s->ctrlr1); /*write len */ - - /*rx only */ - clrsetbits_le32(®s->ctrlr0, SPI_TMOD_MASK << SPI_TMOD_OFFSET, - SPI_TMOD_RO << SPI_TMOD_OFFSET); - while (len) { - writel(0, ®s->spienr);/*disable spi */ - bytes_remaining = MIN(len, 0xffff); - writel(bytes_remaining - 1, ®s->ctrlr1); - len -= bytes_remaining; - writel(1, ®s->spienr);/*enable spi */ - while (bytes_remaining) { - if (readl(®s->rxflr) & 0x3f) { - *p = readl(®s->rxdr) & 0xff; - p += 1; - bytes_remaining--; - } - } + + if (*bytes_in && !(sr & SR_RF_EMPT)) { + *in_buf = readl(®s->rxdr) & 0xff; + in_buf++; + *bytes_in -= 1; + xferred = 1; } - if (rockchip_spi_wait_till_not_busy(regs)) - return -1; + + min_xfer -= xferred; + } + + if (rockchip_spi_wait_till_not_busy(regs)) { + printk(BIOS_ERR, "Timed out waiting on SPI transfer\n"); + return -1; } + return 0; } -static int rockchip_spi_read(struct spi_slave *slave, void *dest, uint32_t len, - uint32_t off) +int spi_xfer(struct spi_slave *slave, const void *dout, + unsigned int bytes_out, void *din, unsigned int bytes_in) { - unsigned int cmd; + struct rockchip_spi *regs = to_rockchip_spi(slave)->regs; + int ret = 0; + + /* + * RK3288 SPI controller can transfer up to 65536 data frames (bytes + * in our case) continuously. Break apart large requests as necessary. + * + * FIXME: And by 65536, we really mean 65535. If 0xffff is written to + * ctrlr1, all bytes that we see in rxdr end up being 0x00. 0xffff - 1 + * seems to work fine. + */ + while (bytes_out || bytes_in) { + unsigned int in_now = MIN(bytes_in, 0xffff); + unsigned int out_now = MIN(bytes_out, 0xffff); + unsigned int in_rem, out_rem; + + rockchip_spi_enable_chip(regs, 0); + + /* Enable/disable transmitter and receiver as needed to + * avoid sending or reading spurious bits. */ + set_transfer_mode(regs, bytes_out, bytes_in); + + /* MAX() in case either counter is 0 */ + writel(MAX(in_now, out_now) - 1, ®s->ctrlr1); + + rockchip_spi_enable_chip(regs, 1); + + in_rem = in_now; + out_rem = out_now; + ret = do_xfer(slave, dout, &out_rem, din, &in_rem); + if (ret < 0) + break; + + if (bytes_out) { + unsigned int sent = out_now - out_rem; + bytes_out -= sent; + dout += sent; + } - spi_claim_bus(slave); - cmd = swab32(off) | SF_READ_DATA_CMD; - if (spi_xfer(slave, &cmd, sizeof(cmd), dest, len)) { - printk(BIOS_DEBUG, "rockchip_spi_read err\n"); - spi_release_bus(slave); - return -1; + if (bytes_in) { + unsigned int received = in_now - in_rem; + bytes_in -= received; + din += received; + } } - spi_release_bus(slave); - return len; + + rockchip_spi_enable_chip(regs, 0); + return ret < 0 ? ret : 0; } struct rockchip_spi_media { @@ -262,10 +306,28 @@ static int rockchip_spi_cbfs_close(struct cbfs_media *media) static size_t rockchip_spi_cbfs_read(struct cbfs_media *media, void *dest, size_t offset, size_t count) { + unsigned int cmd; struct rockchip_spi_media *spi = (struct rockchip_spi_media *)media->context; + int ret; + + spi_claim_bus(spi->slave); + cmd = swab32(offset) | SF_READ_DATA_CMD; + if (spi_xfer(spi->slave, &cmd, sizeof(cmd), NULL, 0)) { + printk(BIOS_DEBUG, "%s: could not send command\n", __func__); + ret = 0; + goto rockchip_spi_cbfs_read_done; + } + + if (spi_xfer(spi->slave, NULL, 0, dest, count)) { + printk(BIOS_DEBUG, "%s: could not receive data\n", __func__); + ret = 0; + goto rockchip_spi_cbfs_read_done; + } - return rockchip_spi_read(spi->slave, dest, count, offset); +rockchip_spi_cbfs_read_done: + spi_release_bus(spi->slave); + return ret < 0 ? 0 : count; } static void *rockchip_spi_cbfs_map(struct cbfs_media *media, size_t offset, |