diff options
| -rw-r--r-- | drivers/spi/spi-zynqmp-gqspi.c | 49 |
1 files changed, 35 insertions, 14 deletions
diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c index 1b56dd29057f..0fecea338027 100644 --- a/drivers/spi/spi-zynqmp-gqspi.c +++ b/drivers/spi/spi-zynqmp-gqspi.c @@ -159,6 +159,7 @@ enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA}; * @mode: Defines the mode in which QSPI is operating * @data_completion: completion structure * @op_lock: Operational lock + * @speed_hz: Current SPI bus clock speed in hz */ struct zynqmp_qspi { struct spi_controller *ctlr; @@ -179,6 +180,7 @@ struct zynqmp_qspi { enum mode_type mode; struct completion data_completion; struct mutex op_lock; + u32 speed_hz; }; /** @@ -273,7 +275,8 @@ static void zynqmp_gqspi_selectslave(struct zynqmp_qspi *instanceptr, */ static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi) { - u32 config_reg; + u32 config_reg, baud_rate_val = 0; + ulong clk_rate; /* Select the GQSPI mode */ zynqmp_gqspi_write(xqspi, GQSPI_SEL_OFST, GQSPI_SEL_MASK); @@ -318,6 +321,16 @@ static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi) else config_reg &= ~GQSPI_CFG_CLK_POL_MASK; + /* Set the clock frequency */ + clk_rate = clk_get_rate(xqspi->refclk); + while ((baud_rate_val < GQSPI_BAUD_DIV_MAX) && + (clk_rate / + (GQSPI_BAUD_DIV_SHIFT << baud_rate_val)) > xqspi->speed_hz) + baud_rate_val++; + + config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK; + config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT); + zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg); /* Clear the TX and RX FIFO */ @@ -466,22 +479,29 @@ static int zynqmp_qspi_config_op(struct zynqmp_qspi *xqspi, struct spi_device *qspi) { ulong clk_rate; - u32 config_reg, baud_rate_val = 0; + u32 config_reg, req_speed_hz, baud_rate_val = 0; - /* Set the clock frequency */ - /* If req_hz == 0, default to lowest speed */ - clk_rate = clk_get_rate(xqspi->refclk); + req_speed_hz = qspi->max_speed_hz; - while ((baud_rate_val < GQSPI_BAUD_DIV_MAX) && - (clk_rate / - (GQSPI_BAUD_DIV_SHIFT << baud_rate_val)) > qspi->max_speed_hz) - baud_rate_val++; + if (xqspi->speed_hz != req_speed_hz) { + xqspi->speed_hz = req_speed_hz; - config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST); + /* Set the clock frequency */ + /* If req_speed_hz == 0, default to lowest speed */ + clk_rate = clk_get_rate(xqspi->refclk); - config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK; - config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT); - zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg); + while ((baud_rate_val < GQSPI_BAUD_DIV_MAX) && + (clk_rate / + (GQSPI_BAUD_DIV_SHIFT << baud_rate_val)) > + req_speed_hz) + baud_rate_val++; + + config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST); + + config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK; + config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT); + zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg); + } return 0; } @@ -1173,6 +1193,8 @@ static int zynqmp_qspi_probe(struct platform_device *pdev) ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD | SPI_TX_DUAL | SPI_TX_QUAD; + ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2; + xqspi->speed_hz = ctlr->max_speed_hz; /* QSPI controller initializations */ zynqmp_qspi_init_hw(xqspi); @@ -1209,7 +1231,6 @@ static int zynqmp_qspi_probe(struct platform_device *pdev) ctlr->bits_per_word_mask = SPI_BPW_MASK(8); ctlr->mem_ops = &zynqmp_qspi_mem_ops; ctlr->setup = zynqmp_qspi_setup_op; - ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2; ctlr->bits_per_word_mask = SPI_BPW_MASK(8); ctlr->dev.of_node = np; ctlr->auto_runtime_pm = true; |