linux-kernel - [PATCH 1/2] spi: rockchip: add support for "cs-gpios" dts property

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Date:   Mon, 12 Jun 2017 14:14:15 +0800
From:   Jeffy Chen <jeffy.chen@...k-chips.com>
To:     linux-kernel@...r.kernel.org, broonie@...nel.org
Cc:     briannorris@...omium.org, dianders@...omium.org, heiko@...ech.de,
        Jeffy Chen <jeffy.chen@...k-chips.com>,
        devicetree@...r.kernel.org, linux-spi@...r.kernel.org,
        linux-rockchip@...ts.infradead.org,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        linux-arm-kernel@...ts.infradead.org
Subject: [PATCH 1/2] spi: rockchip: add support for "cs-gpios" dts property

Support using "cs-gpios" property to specify cs gpios.

Signed-off-by: Jeffy Chen <jeffy.chen@...k-chips.com>
---

 .../devicetree/bindings/spi/spi-rockchip.txt       |  2 +
 drivers/spi/spi-rockchip.c                         | 52 ++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/spi-rockchip.txt b/Documentation/devicetree/bindings/spi/spi-rockchip.txt
index 83da493..02171b2 100644
--- a/Documentation/devicetree/bindings/spi/spi-rockchip.txt
+++ b/Documentation/devicetree/bindings/spi/spi-rockchip.txt
@@ -17,6 +17,7 @@ Required Properties:
        region.
 - interrupts: The interrupt number to the cpu. The interrupt specifier format
               depends on the interrupt controller.
+- cs-gpios : Specifies the gpio pins to be used for chipselects.
 - clocks: Must contain an entry for each entry in clock-names.
 - clock-names: Shall be "spiclk" for the transfer-clock, and "apb_pclk" for
 			   the peripheral clock.
@@ -48,6 +49,7 @@ Example:
 		#address-cells = <1>;
 		#size-cells = <0>;
 		interrupts = <GIC_SPI 44 IRQ_TYPE_LEVEL_HIGH>;
+		cs-gpios = <&gpio2 23 GPIO_ACTIVE_HIGH>;
 		clocks = <&cru SCLK_SPI0>, <&cru PCLK_SPI0>;
 		clock-names = "spiclk", "apb_pclk";
 		pinctrl-0 = <&spi1_pins>;
diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index acf31f3..04694e1 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -15,6 +15,7 @@
 
 #include <linux/clk.h>
 #include <linux/dmaengine.h>
+#include <linux/gpio.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/pinctrl/consumer.h>
@@ -201,6 +202,10 @@ struct rockchip_spi {
 	struct dma_slave_caps dma_caps;
 };
 
+struct rockchip_spi_data {
+	bool cs_gpio_requested;
+};
+
 static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
 {
 	writel_relaxed((enable ? 1 : 0), rs->regs + ROCKCHIP_SPI_SSIENR);
@@ -297,6 +302,50 @@ static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
 	pm_runtime_put_sync(rs->dev);
 }
 
+static int rockchip_spi_setup(struct spi_device *spi)
+{
+	int ret = 0;
+	unsigned long flags = (spi->mode & SPI_CS_HIGH) ?
+			      GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH;
+	struct rockchip_spi_data *data = spi_get_ctldata(spi);
+
+	if (!gpio_is_valid(spi->cs_gpio))
+		return 0;
+
+	if (!data) {
+		data = kzalloc(sizeof(*data), GFP_KERNEL);
+		if (!data)
+			return -ENOMEM;
+		spi_set_ctldata(spi, data);
+	}
+
+	if (!data->cs_gpio_requested) {
+		ret = gpio_request_one(spi->cs_gpio, flags,
+				       dev_name(&spi->dev));
+		if (!ret)
+			data->cs_gpio_requested = 1;
+	} else
+		ret = gpio_direction_output(spi->cs_gpio, flags);
+
+	if (ret < 0)
+		dev_err(&spi->dev, "Failed to setup cs gpio(%d): %d\n",
+			spi->cs_gpio, ret);
+
+	return ret;
+}
+
+static void rockchip_spi_cleanup(struct spi_device *spi)
+{
+	struct rockchip_spi_data *data = spi_get_ctldata(spi);
+
+	if (data) {
+		if (data->cs_gpio_requested)
+			gpio_free(spi->cs_gpio);
+		kfree(data);
+		spi_set_ctldata(spi, NULL);
+	}
+}
+
 static int rockchip_spi_prepare_message(struct spi_master *master,
 					struct spi_message *msg)
 {
@@ -744,11 +793,14 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
 
 	master->set_cs = rockchip_spi_set_cs;
+	master->setup = rockchip_spi_setup;
+	master->cleanup = rockchip_spi_cleanup;
 	master->prepare_message = rockchip_spi_prepare_message;
 	master->unprepare_message = rockchip_spi_unprepare_message;
 	master->transfer_one = rockchip_spi_transfer_one;
 	master->max_transfer_size = rockchip_spi_max_transfer_size;
 	master->handle_err = rockchip_spi_handle_err;
+	master->flags = SPI_MASTER_GPIO_SS;
 
 	rs->dma_tx.ch = dma_request_chan(rs->dev, "tx");
 	if (IS_ERR(rs->dma_tx.ch)) {
-- 
2.1.4