From afb907061a0a2175c840e8bfc3ad04fd2d6721ed Mon Sep 17 00:00:00 2001 From: Hou Zhiqiang Date: Wed, 21 May 2014 10:25:10 +0800 Subject: [PATCH] powerpc/espi: remove 80us delay to improve transfer performance Replace 80 mircoseconds delay with polling flag ESPI_EV_TXE. Signed-off-by: Hou Zhiqiang Reviewed-by: York Sun --- drivers/spi/fsl_espi.c | 138 +++++++++++++++++++++++++++++++---------- 1 file changed, 106 insertions(+), 32 deletions(-) diff --git a/drivers/spi/fsl_espi.c b/drivers/spi/fsl_espi.c index 7c84582762..ae0fe58f2c 100644 --- a/drivers/spi/fsl_espi.c +++ b/drivers/spi/fsl_espi.c @@ -15,8 +15,10 @@ struct fsl_spi_slave { struct spi_slave slave; + ccsr_espi_t *espi; unsigned int div16; unsigned int pm; + int tx_timeout; unsigned int mode; size_t cmd_len; u8 cmd_buf[16]; @@ -25,11 +27,17 @@ struct fsl_spi_slave { }; #define to_fsl_spi_slave(s) container_of(s, struct fsl_spi_slave, slave) +#define US_PER_SECOND 1000000UL #define ESPI_MAX_CS_NUM 4 +#define ESPI_FIFO_WIDTH_BIT 32 #define ESPI_EV_RNE (1 << 9) #define ESPI_EV_TNF (1 << 8) +#define ESPI_EV_DON (1 << 14) +#define ESPI_EV_TXE (1 << 15) +#define ESPI_EV_RFCNT_SHIFT 24 +#define ESPI_EV_RFCNT_MASK (0x3f << ESPI_EV_RFCNT_SHIFT) #define ESPI_MODE_EN (1 << 31) /* Enable interface */ #define ESPI_MODE_TXTHR(x) ((x) << 8) /* Tx FIFO threshold */ @@ -61,6 +69,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, struct fsl_spi_slave *fsl; sys_info_t sysinfo; unsigned long spibrg = 0; + unsigned long spi_freq = 0; unsigned char pm = 0; if (!spi_cs_is_valid(bus, cs)) @@ -70,6 +79,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, if (!fsl) return NULL; + fsl->espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR); fsl->mode = mode; fsl->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN; @@ -91,6 +101,15 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, pm--; fsl->pm = pm; + if (fsl->div16) + spi_freq = spibrg / ((pm + 1) * 2 * 16); + else + spi_freq = spibrg / ((pm + 1) * 2); + + /* set tx_timeout to 10 times of one espi FIFO entry go out */ + fsl->tx_timeout = DIV_ROUND_UP((US_PER_SECOND * ESPI_FIFO_WIDTH_BIT + * 10), spi_freq); + return &fsl->slave; } @@ -108,7 +127,7 @@ void spi_init(void) int spi_claim_bus(struct spi_slave *slave) { struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave); - ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR); + ccsr_espi_t *espi = fsl->espi; unsigned char pm = fsl->pm; unsigned int cs = slave->cs; unsigned int mode = fsl->mode; @@ -161,24 +180,86 @@ void spi_release_bus(struct spi_slave *slave) } +static void fsl_espi_tx(struct fsl_spi_slave *fsl, const void *dout) +{ + ccsr_espi_t *espi = fsl->espi; + unsigned int tmpdout, event; + int tmp_tx_timeout; + + if (dout) + tmpdout = *(u32 *)dout; + else + tmpdout = 0; + + out_be32(&espi->tx, tmpdout); + out_be32(&espi->event, ESPI_EV_TNF); + debug("***spi_xfer:...%08x written\n", tmpdout); + + tmp_tx_timeout = fsl->tx_timeout; + /* Wait for eSPI transmit to go out */ + while (tmp_tx_timeout--) { + event = in_be32(&espi->event); + if (event & ESPI_EV_DON || event & ESPI_EV_TXE) { + out_be32(&espi->event, ESPI_EV_TXE); + break; + } + udelay(1); + } + + if (tmp_tx_timeout < 0) + debug("***spi_xfer:...Tx timeout! event = %08x\n", event); +} + +static int fsl_espi_rx(struct fsl_spi_slave *fsl, void *din, unsigned int bytes) +{ + ccsr_espi_t *espi = fsl->espi; + unsigned int tmpdin, rx_times; + unsigned char *buf, *p_cursor; + + if (bytes <= 0) + return 0; + + rx_times = DIV_ROUND_UP(bytes, 4); + buf = (unsigned char *)malloc(4 * rx_times); + if (!buf) { + debug("SF: Failed to malloc memory.\n"); + return -1; + } + p_cursor = buf; + while (rx_times--) { + tmpdin = in_be32(&espi->rx); + debug("***spi_xfer:...%08x readed\n", tmpdin); + *(u32 *)p_cursor = tmpdin; + p_cursor += 4; + } + + if (din) + memcpy(din, buf, bytes); + + free(buf); + out_be32(&espi->event, ESPI_EV_RNE); + + return bytes; +} + int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out, void *data_in, unsigned long flags) { struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave); - ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR); - unsigned int tmpdout, tmpdin, event; + ccsr_espi_t *espi = fsl->espi; + unsigned int event, rx_bytes; const void *dout = NULL; void *din = NULL; int len = 0; int num_blks, num_chunks, max_tran_len, tran_len; int num_bytes; - unsigned char *ch; unsigned char *buffer = NULL; size_t buf_len; u8 *cmd_buf = fsl->cmd_buf; size_t cmd_len = fsl->cmd_len; size_t data_len = bitlen / 8; size_t rx_offset = 0; + int rf_cnt; max_tran_len = fsl->max_transfer_length; switch (flags) { @@ -217,9 +298,8 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out, break; } - debug("spi_xfer: slave %u:%u dout %08X(%p) din %08X(%p) len %u\n", - slave->bus, slave->cs, *(uint *) dout, - dout, *(uint *) din, din, len); + debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) len %u\n", + *(uint *)data_out, data_out, *(uint *)data_in, data_in, len); num_chunks = DIV_ROUND_UP(data_len, max_tran_len); while (num_chunks--) { @@ -235,41 +315,34 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out, /* Clear all eSPI events */ out_be32(&espi->event , 0xffffffff); /* handle data in 32-bit chunks */ - while (num_blks--) { - + while (num_blks) { event = in_be32(&espi->event); if (event & ESPI_EV_TNF) { - tmpdout = *(u32 *)dout; - + fsl_espi_tx(fsl, dout); /* Set up the next iteration */ if (len > 4) { len -= 4; dout += 4; } - - out_be32(&espi->tx, tmpdout); - out_be32(&espi->event, ESPI_EV_TNF); - debug("***spi_xfer:...%08x written\n", tmpdout); } - /* Wait for eSPI transmit to get out */ - udelay(80); - event = in_be32(&espi->event); if (event & ESPI_EV_RNE) { - tmpdin = in_be32(&espi->rx); - if (num_blks == 0 && num_bytes != 0) { - ch = (unsigned char *)&tmpdin; - while (num_bytes--) - *(unsigned char *)din++ = *ch++; - } else { - *(u32 *) din = tmpdin; - din += 4; + rf_cnt = ((event & ESPI_EV_RFCNT_MASK) + >> ESPI_EV_RFCNT_SHIFT); + if (rf_cnt >= 4) + rx_bytes = 4; + else if (num_blks == 1 && rf_cnt == num_bytes) + rx_bytes = num_bytes; + else + continue; + if (fsl_espi_rx(fsl, din, rx_bytes) + == rx_bytes) { + num_blks--; + if (din) + din = (unsigned char *)din + + rx_bytes; } - - out_be32(&espi->event, in_be32(&espi->event) - | ESPI_EV_RNE); - debug("***spi_xfer:...%08x readed\n", tmpdin); } } if (data_in) { @@ -295,7 +368,7 @@ int spi_cs_is_valid(unsigned int bus, unsigned int cs) void spi_cs_activate(struct spi_slave *slave) { struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave); - ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR); + ccsr_espi_t *espi = fsl->espi; unsigned int com = 0; size_t data_len = fsl->data_len; @@ -307,7 +380,8 @@ void spi_cs_activate(struct spi_slave *slave) void spi_cs_deactivate(struct spi_slave *slave) { - ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR); + struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave); + ccsr_espi_t *espi = fsl->espi; /* clear the RXCNT and TXCNT */ out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN)); -- 2.30.2