Date:	Wed, 30 Mar 2016 15:58:14 +0300
From:	Eyal Reizer <eyalreizer@...il.com>
To:	kvalo@...eaurora.org, linux-wireless@...r.kernel.org,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:	Eyal Reizer <eyalr@...com>
Subject: [PATCH] wlcore: spi: add wl18xx support

From: Eyal <eyalr@...lr-VirtualBox.(none)>

Add support for using with both wl12xx and wl18xx.

- all wilink family needs special init command for entering wspi mode.
  extra clock cycles should be sent after the spi init command while the
  cs pin is high.
- switch to controling the cs pin from the spi driver for achieveing the
  above.
- the selected cs gpio is read from the spi device-tree node using the
  cs-gpios field and setup as a gpio.
- See the example below for specifying the cs gpio using the cs-gpios entry

&spi0	{
 	status = "okay";
	pinctrl-names = "default";
	pinctrl-0 = <&spi0_pins>;
	cs-gpios = <&gpio0 5 0>;
	#address-cells = <1>;
	#size-cells = <0>;
 	wlcore: wlcore@0 {
		compatible = "ti,wl1835";
		vwlan-supply = <&wlan_en_reg>;
		spi-max-frequency = <48000000>;
		reg = <0>;      /* chip select 0 on spi0, ie spi0.0 */
		interrupt-parent = <&gpio0>;
		interrupts = <27 IRQ_TYPE_EDGE_RISING>;
 	};
};

Signed-off-by: Eyal Reizer <eyalr@...com>
---
 drivers/net/wireless/ti/wlcore/spi.c |  176 ++++++++++++++++++++++++++++++----
 1 file changed, 157 insertions(+), 19 deletions(-)

diff --git a/drivers/net/wireless/ti/wlcore/spi.c b/drivers/net/wireless/ti/wlcore/spi.c
index 96d9c9d..6c5a369 100644
--- a/drivers/net/wireless/ti/wlcore/spi.c
+++ b/drivers/net/wireless/ti/wlcore/spi.c
@@ -32,6 +32,7 @@
 #include <linux/platform_device.h>
 #include <linux/of_irq.h>
 #include <linux/regulator/consumer.h>
+#include <linux/gpio.h>
 
 #include "wlcore.h"
 #include "wl12xx_80211.h"
@@ -70,16 +71,30 @@
 #define WSPI_MAX_CHUNK_SIZE    4092
 
 /*
- * only support SPI for 12xx - this code should be reworked when 18xx
- * support is introduced
+ * wl18xx driver aggregation buffer size is (13 * PAGE_SIZE) compared to
+ * (4 * PAGE_SIZE) for wl12xx, so use the larger buffer needed for wl18xx
  */
-#define SPI_AGGR_BUFFER_SIZE (4 * PAGE_SIZE)
+#define SPI_AGGR_BUFFER_SIZE (13 * PAGE_SIZE)
 
 /* Maximum number of SPI write chunks */
 #define WSPI_MAX_NUM_OF_CHUNKS \
 	((SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE) + 1)
 
 
+struct wilink_familiy_data {
+	char name[8];
+};
+
+const struct wilink_familiy_data *wilink_data;
+
+static const struct wilink_familiy_data wl18xx_data = {
+	.name = "wl18xx",
+};
+
+static const struct wilink_familiy_data wl12xx_data = {
+	.name = "wl12xx",
+};
+
 struct wl12xx_spi_glue {
 	struct device *dev;
 	struct platform_device *core;
@@ -120,6 +135,8 @@ static void wl12xx_spi_init(struct device *child)
 	struct spi_transfer t;
 	struct spi_message m;
 	u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
+	struct spi_device *spi = (struct spi_device *)glue->dev;
+	struct spi_master *master = spi->master;
 
 	if (!cmd) {
 		dev_err(child->parent,
@@ -127,6 +144,15 @@ static void wl12xx_spi_init(struct device *child)
 		return;
 	}
 
+	if (!master->cs_gpios) {
+		dev_err(child->parent,
+			"spi chip select pin missing in platform data!\n");
+		return;
+	}
+
+	/* Drive CS line low */
+	gpio_direction_output(master->cs_gpios[0], 0);
+
 	memset(&t, 0, sizeof(t));
 	spi_message_init(&m);
 
@@ -163,6 +189,26 @@ static void wl12xx_spi_init(struct device *child)
 	spi_message_add_tail(&t, &m);
 
 	spi_sync(to_spi_device(glue->dev), &m);
+
+	/* Send extra clocks with CS high. this is required by the wilink
+	 * family in order for successfully enter WSPI mode
+	 */
+	gpio_direction_output(master->cs_gpios[0], 1);
+
+	memset(&m, 0, sizeof(m));
+	spi_message_init(&m);
+
+	cmd[0] = 0xff;
+	cmd[1] = 0xff;
+	cmd[2] = 0xff;
+	cmd[3] = 0xff;
+	swab32s((u32 *)cmd);
+
+	t.tx_buf = cmd;
+	t.len = 4;
+	spi_message_add_tail(&t, &m);
+	spi_sync(to_spi_device(glue->dev), &m);
+
 	kfree(cmd);
 }
 
@@ -213,6 +259,16 @@ static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
 	u32 *busy_buf;
 	u32 *cmd;
 	u32 chunk_len;
+	struct spi_device *spi = (struct spi_device *)glue->dev;
+	struct spi_master *master = spi->master;
+
+	if (!master->cs_gpios) {
+		dev_err(child->parent,
+			"spi chip select pin missing in platform data!\n");
+		return -EINVAL;
+	}
+	/* Drive CS line low */
+	gpio_direction_output(master->cs_gpios[0], 0);
 
 	while (len > 0) {
 		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
@@ -267,25 +323,44 @@ static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
 		len -= chunk_len;
 	}
 
+	/* Drive CS line high */
+	gpio_direction_output(master->cs_gpios[0], 1);
 	return 0;
 }
 
-static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
-					     void *buf, size_t len, bool fixed)
+static int __wl12xx_spi_raw_write(struct device *child, int addr,
+				  void *buf, size_t len, bool fixed)
 {
 	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
-	/* SPI write buffers - 2 for each chunk */
-	struct spi_transfer t[2 * WSPI_MAX_NUM_OF_CHUNKS];
+	struct spi_transfer *t;
 	struct spi_message m;
 	u32 commands[WSPI_MAX_NUM_OF_CHUNKS]; /* 1 command per chunk */
 	u32 *cmd;
 	u32 chunk_len;
 	int i;
+	struct spi_device *spi = (struct spi_device *)glue->dev;
+	struct spi_master *master = spi->master;
+
+	if (!master->cs_gpios) {
+		dev_err(child->parent,
+			"spi chip select pin missing in platform data!\n");
+		return -EINVAL;
+	}
+
+	/* SPI write buffers - 2 for each chunk */
+	t = kzalloc(sizeof(*t) * 2 * WSPI_MAX_NUM_OF_CHUNKS, GFP_KERNEL);
+	if (!t) {
+		dev_err(child->parent,
+			"could not allocate spi write buffer\n");
+		return -ENOMEM;
+	}
+
+	/* Drive CS line low */
+	gpio_direction_output(master->cs_gpios[0], 0);
 
 	WARN_ON(len > SPI_AGGR_BUFFER_SIZE);
 
 	spi_message_init(&m);
-	memset(t, 0, sizeof(t));
 
 	cmd = &commands[0];
 	i = 0;
@@ -318,9 +393,29 @@ static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
 
 	spi_sync(to_spi_device(glue->dev), &m);
 
+	/* Drive CS line high */
+	gpio_direction_output(master->cs_gpios[0], 1);
+
+	kfree(t);
 	return 0;
 }
 
+static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
+					     void *buf, size_t len, bool fixed)
+{
+	int ret;
+
+	/* The ELP wakeup write may fail the first time due to internal
+	 * hardware latency. It is safer to send the wakeup command twice to
+	 * avoid unexpected failures.
+	 */
+	if (addr == HW_ACCESS_ELP_CTRL_REG)
+		ret = __wl12xx_spi_raw_write(child, addr, buf, len, fixed);
+	ret = __wl12xx_spi_raw_write(child, addr, buf, len, fixed);
+
+	return ret;
+}
+
 /**
  * wl12xx_spi_set_power - power on/off the wl12xx unit
  * @child: wl12xx device handle.
@@ -349,17 +444,38 @@ static int wl12xx_spi_set_power(struct device *child, bool enable)
 	return ret;
 }
 
+/**
+ * wl12xx_spi_set_block_size
+ *
+ * This function is not needed for spi mode, but need to be present.
+ * Without it defined the wlcore fallback to use the wrong packet
+ * allignment on tx.
+ */
+static void wl12xx_spi_set_block_size(struct device *child,
+				      unsigned int blksz)
+{
+}
+
 static struct wl1271_if_operations spi_ops = {
 	.read		= wl12xx_spi_raw_read,
 	.write		= wl12xx_spi_raw_write,
 	.reset		= wl12xx_spi_reset,
 	.init		= wl12xx_spi_init,
 	.power		= wl12xx_spi_set_power,
-	.set_block_size = NULL,
+	.set_block_size = wl12xx_spi_set_block_size,
 };
 
 static const struct of_device_id wlcore_spi_of_match_table[] = {
-	{ .compatible = "ti,wl1271" },
+	{ .compatible = "ti,wl1271", .data = &wl12xx_data},
+	{ .compatible = "ti,wl1273", .data = &wl12xx_data},
+	{ .compatible = "ti,wl1281", .data = &wl12xx_data},
+	{ .compatible = "ti,wl1283", .data = &wl12xx_data},
+	{ .compatible = "ti,wl1801", .data = &wl18xx_data},
+	{ .compatible = "ti,wl1805", .data = &wl18xx_data},
+	{ .compatible = "ti,wl1807", .data = &wl18xx_data},
+	{ .compatible = "ti,wl1831", .data = &wl18xx_data},
+	{ .compatible = "ti,wl1835", .data = &wl18xx_data},
+	{ .compatible = "ti,wl1837", .data = &wl18xx_data},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, wlcore_spi_of_match_table);
@@ -375,18 +491,24 @@ static int wlcore_probe_of(struct spi_device *spi, struct wl12xx_spi_glue *glue,
 			   struct wlcore_platdev_data *pdev_data)
 {
 	struct device_node *dt_node = spi->dev.of_node;
-	int ret;
+	const struct of_device_id *of_id;
+
+	of_id = of_match_node(wlcore_spi_of_match_table, dt_node);
+	if (!of_id)
+		return -ENODEV;
+
+	wilink_data = of_id->data;
+	dev_info(&spi->dev, "selected chip familiy is %s\n",
+		 wilink_data->name);
 
 	if (of_find_property(dt_node, "clock-xtal", NULL))
 		pdev_data->ref_clock_xtal = true;
 
-	ret = of_property_read_u32(dt_node, "ref-clock-frequency",
-				   &pdev_data->ref_clock_freq);
-	if (IS_ERR_VALUE(ret)) {
-		dev_err(glue->dev,
-			"can't get reference clock frequency (%d)\n", ret);
-		return ret;
-	}
+	/* optional clock frequency params */
+	of_property_read_u32(dt_node, "ref-clock-frequency",
+			     &pdev_data->ref_clock_freq);
+	of_property_read_u32(dt_node, "tcxo-clock-frequency",
+			     &pdev_data->tcxo_clock_freq);
 
 	return 0;
 }
@@ -397,6 +519,7 @@ static int wl1271_probe(struct spi_device *spi)
 	struct wlcore_platdev_data pdev_data;
 	struct resource res[1];
 	int ret;
+	struct spi_master *master = spi->master;
 
 	memset(&pdev_data, 0x00, sizeof(pdev_data));
 
@@ -410,6 +533,12 @@ static int wl1271_probe(struct spi_device *spi)
 
 	glue->dev = &spi->dev;
 
+	if (!master->cs_gpios) {
+		dev_err(glue->dev,
+			"spi chip select pin missing in platform data!\n");
+		return -EINVAL;
+	}
+
 	spi_set_drvdata(spi, glue);
 
 	/* This is the only SPI value that we need to set here, the rest
@@ -431,15 +560,21 @@ static int wl1271_probe(struct spi_device *spi)
 		return ret;
 	}
 
+	if (gpio_request(master->cs_gpios[0], "spi1-cs0"))
+		return -EINVAL;
+
 	ret = spi_setup(spi);
 	if (ret < 0) {
 		dev_err(glue->dev, "spi_setup failed\n");
+		gpio_free(master->cs_gpios[0]);
 		return ret;
 	}
 
-	glue->core = platform_device_alloc("wl12xx", PLATFORM_DEVID_AUTO);
+	glue->core = platform_device_alloc(wilink_data->name,
+					   PLATFORM_DEVID_AUTO);
 	if (!glue->core) {
 		dev_err(glue->dev, "can't allocate platform_device\n");
+		gpio_free(master->cs_gpios[0]);
 		return -ENOMEM;
 	}
 
@@ -474,14 +609,17 @@ static int wl1271_probe(struct spi_device *spi)
 
 out_dev_put:
 	platform_device_put(glue->core);
+	gpio_free(master->cs_gpios[0]);
 	return ret;
 }
 
 static int wl1271_remove(struct spi_device *spi)
 {
 	struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
+	struct spi_master *master = spi->master;
 
 	platform_device_unregister(glue->core);
+	gpio_free(master->cs_gpios[0]);
 
 	return 0;
 }
-- 
1.7.9.5

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