From dd9c232d47277960aba0c603c87a1cfd85d69438 Mon Sep 17 00:00:00 2001 From: Amit Kumar Mahapatra Date: Thu, 12 May 2022 20:28:20 +0530 Subject: [PATCH] spi: spi-zynqmp-gqspi: Add two chip select support ZynqMP GQSPI controller can support up to two chip selects but the current GQSPI driver only support CS0. With this update and num-cs DT property set to 2 GQSPI driver can now support two slave devices each connected to one chip select. GQSPI driver configures the Lower CS and Upper CS based on the reg DT property. Changes tested on ZynqMP board with two SPI-NOR flashes each connected to a different CS. Signed-off-by: Amit Kumar Mahapatra Link: https://lore.kernel.org/r/20220512145820.20425-1-amit.kumar-mahapatra@xilinx.com Signed-off-by: Mark Brown --- drivers/spi/spi-zynqmp-gqspi.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-zynqmp-gqspi.c b/drivers/spi/spi-zynqmp-gqspi.c index 2b5afae8ff7fc..c760aac070e54 100644 --- a/drivers/spi/spi-zynqmp-gqspi.c +++ b/drivers/spi/spi-zynqmp-gqspi.c @@ -134,6 +134,8 @@ #define GQSPI_DMA_UNALIGN 0x3 #define GQSPI_DEFAULT_NUM_CS 1 /* Default number of chip selects */ +#define GQSPI_MAX_NUM_CS 2 /* Maximum number of chip selects */ + #define SPI_AUTOSUSPEND_TIMEOUT 3000 enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA}; @@ -363,8 +365,13 @@ static void zynqmp_qspi_chipselect(struct spi_device *qspi, bool is_high) genfifoentry |= GQSPI_GENFIFO_MODE_SPI; if (!is_high) { - xqspi->genfifobus = GQSPI_GENFIFO_BUS_LOWER; - xqspi->genfifocs = GQSPI_GENFIFO_CS_LOWER; + if (!qspi->chip_select) { + xqspi->genfifobus = GQSPI_GENFIFO_BUS_LOWER; + xqspi->genfifocs = GQSPI_GENFIFO_CS_LOWER; + } else { + xqspi->genfifobus = GQSPI_GENFIFO_BUS_UPPER; + xqspi->genfifocs = GQSPI_GENFIFO_CS_UPPER; + } genfifoentry |= xqspi->genfifobus; genfifoentry |= xqspi->genfifocs; genfifoentry |= GQSPI_GENFIFO_CS_SETUP; @@ -1099,6 +1106,7 @@ static int zynqmp_qspi_probe(struct platform_device *pdev) struct zynqmp_qspi *xqspi; struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; + u32 num_cs; ctlr = spi_alloc_master(&pdev->dev, sizeof(*xqspi)); if (!ctlr) @@ -1176,8 +1184,19 @@ static int zynqmp_qspi_probe(struct platform_device *pdev) if (ret) goto clk_dis_all; + ret = of_property_read_u32(np, "num-cs", &num_cs); + if (ret < 0) { + ctlr->num_chipselect = GQSPI_DEFAULT_NUM_CS; + } else if (num_cs > GQSPI_MAX_NUM_CS) { + ret = -EINVAL; + dev_err(&pdev->dev, "only %d chip selects are available\n", + GQSPI_MAX_NUM_CS); + goto clk_dis_all; + } else { + ctlr->num_chipselect = num_cs; + } + ctlr->bits_per_word_mask = SPI_BPW_MASK(8); - ctlr->num_chipselect = GQSPI_DEFAULT_NUM_CS; ctlr->mem_ops = &zynqmp_qspi_mem_ops; ctlr->setup = zynqmp_qspi_setup_op; ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;