int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, void *din, unsigned long flags) { struct sh_spi *ss = to_sh_spi(slave); const unsigned char *tx_data = dout; unsigned char *rx_data = din; unsigned int len = bitlen / 8; int ret = 0; if (flags & SPI_XFER_BEGIN) sh_spi_write(sh_spi_read(&ss->regs->cr1) & ~SH_SPI_SSA, &ss->regs->cr1); if (tx_data) ret = sh_spi_send(ss, tx_data, len, flags); if (ret == 0 && rx_data) ret = sh_spi_receive(ss, rx_data, len, flags); if (flags & SPI_XFER_END) { sh_spi_set_bit(SH_SPI_SSD, &ss->regs->cr1); udelay(100); sh_spi_clear_bit(SH_SPI_SSA | SH_SPI_SSDB | SH_SPI_SSD, &ss->regs->cr1); clear_fifo(ss); } return ret; }
static void sh_spi_set_cs(struct sh_spi *ss, unsigned int cs) { unsigned long val = 0; if (cs & 0x01) val |= SH_SPI_SSS0; if (cs & 0x02) val |= SH_SPI_SSS1; sh_spi_clear_bit(SH_SPI_SSS0 | SH_SPI_SSS1, &ss->regs->cr4); sh_spi_set_bit(val, &ss->regs->cr4); }
static int sh_spi_send(struct sh_spi *ss, const unsigned char *tx_data, unsigned int len, unsigned long flags) { int i, cur_len, ret = 0; int remain = (int)len; if (len >= SH_SPI_FIFO_SIZE) sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1); while (remain > 0) { cur_len = (remain < SH_SPI_FIFO_SIZE) ? remain : SH_SPI_FIFO_SIZE; for (i = 0; i < cur_len && !(sh_spi_read(&ss->regs->cr4) & SH_SPI_WPABRT) && !(sh_spi_read(&ss->regs->cr1) & SH_SPI_TBF); i++) sh_spi_write(tx_data[i], &ss->regs->tbr_rbr); cur_len = i; if (sh_spi_read(&ss->regs->cr4) & SH_SPI_WPABRT) { /* Abort the transaction */ flags |= SPI_XFER_END; sh_spi_set_bit(SH_SPI_WPABRT, &ss->regs->cr4); ret = 1; break; } remain -= cur_len; tx_data += cur_len; if (remain > 0) write_fifo_empty_wait(ss); } if (flags & SPI_XFER_END) { sh_spi_clear_bit(SH_SPI_SSD | SH_SPI_SSDB, &ss->regs->cr1); sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1); udelay(100); write_fifo_empty_wait(ss); } return ret; }
static int sh_spi_receive(struct sh_spi *ss, unsigned char *rx_data, unsigned int len, unsigned long flags) { int i; if (len > SH_SPI_MAX_BYTE) sh_spi_write(SH_SPI_MAX_BYTE, &ss->regs->cr3); else sh_spi_write(len, &ss->regs->cr3); sh_spi_clear_bit(SH_SPI_SSD | SH_SPI_SSDB, &ss->regs->cr1); sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1); for (i = 0; i < len; i++) { if (recvbuf_wait(ss)) return 0; rx_data[i] = (unsigned char)sh_spi_read(&ss->regs->tbr_rbr); } sh_spi_write(0, &ss->regs->cr3); return 0; }
static void clear_fifo(struct sh_spi *ss) { sh_spi_set_bit(SH_SPI_RSTF, &ss->regs->cr2); sh_spi_clear_bit(SH_SPI_RSTF, &ss->regs->cr2); }