From 4a8573abe965115bc5b064401fd669b74e985258 Mon Sep 17 00:00:00 2001 From: Andy Gross Date: Thu, 12 Jun 2014 14:34:10 -0500 Subject: [PATCH] spi: qup: Remove chip select function This patch removes the chip select function. Chip select should instead be supported using GPIOs, defining the DT entry "cs-gpios", and letting the SPI core assert/deassert the chip select as it sees fit. The chip select control inside the controller is buggy. It is supposed to automatically assert the chip select based on the activity in the controller, but it is buggy and doesn't work at all. So instead we elect to use GPIOs. Signed-off-by: Andy Gross Signed-off-by: Mark Brown --- .../devicetree/bindings/spi/qcom,spi-qup.txt | 6 ++++ drivers/spi/spi-qup.c | 33 ++++--------------- 2 files changed, 12 insertions(+), 27 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt b/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt index b82a268f1bd4..bee6ff204baf 100644 --- a/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt +++ b/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt @@ -23,6 +23,12 @@ Optional properties: - spi-max-frequency: Specifies maximum SPI clock frequency, Units - Hz. Definition as per Documentation/devicetree/bindings/spi/spi-bus.txt +- num-cs: total number of chipselects +- cs-gpios: should specify GPIOs used for chipselects. + The gpios will be referred to as reg = in the SPI child + nodes. If unspecified, a single SPI device without a chip + select can be used. + SPI slave nodes must be children of the SPI master node and can contain properties described in Documentation/devicetree/bindings/spi/spi-bus.txt diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c index e783e4ce2cdc..c08da380cb23 100644 --- a/drivers/spi/spi-qup.c +++ b/drivers/spi/spi-qup.c @@ -424,31 +424,6 @@ static int spi_qup_io_config(struct spi_device *spi, struct spi_transfer *xfer) return 0; } -static void spi_qup_set_cs(struct spi_device *spi, bool enable) -{ - struct spi_qup *controller = spi_master_get_devdata(spi->master); - - u32 iocontol, mask; - - iocontol = readl_relaxed(controller->base + SPI_IO_CONTROL); - - /* Disable auto CS toggle and use manual */ - iocontol &= ~SPI_IO_C_MX_CS_MODE; - iocontol |= SPI_IO_C_FORCE_CS; - - iocontol &= ~SPI_IO_C_CS_SELECT_MASK; - iocontol |= SPI_IO_C_CS_SELECT(spi->chip_select); - - mask = SPI_IO_C_CS_N_POLARITY_0 << spi->chip_select; - - if (enable) - iocontol |= mask; - else - iocontol &= ~mask; - - writel_relaxed(iocontol, controller->base + SPI_IO_CONTROL); -} - static int spi_qup_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) @@ -571,12 +546,16 @@ static int spi_qup_probe(struct platform_device *pdev) return -ENOMEM; } + /* use num-cs unless not present or out of range */ + if (of_property_read_u16(dev->of_node, "num-cs", + &master->num_chipselect) || + (master->num_chipselect > SPI_NUM_CHIPSELECTS)) + master->num_chipselect = SPI_NUM_CHIPSELECTS; + master->bus_num = pdev->id; master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP; - master->num_chipselect = SPI_NUM_CHIPSELECTS; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32); master->max_speed_hz = max_freq; - master->set_cs = spi_qup_set_cs; master->transfer_one = spi_qup_transfer_one; master->dev.of_node = pdev->dev.of_node; master->auto_runtime_pm = true; -- 2.20.1