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Subject[Patch v2 1/3] spi: qup: Remove chip select function
Date
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.

Signed-off-by: Andy Gross <agross@codeaurora.org>
---
.../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 b82a268..bee6ff2 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 = <index> 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 fc1de86..3938c62 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;
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation


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