SPI : add a skeleton

Author: 54shady

debug/spi/README.md

@@ -0,0 +1,9 @@
+# SPI
+
+spi_transfer数据结构
+
+	struct spi_transfer - a read/write buffer pair
+	@tx_buf: data to be written (dma-safe memory), or NULL
+	@rx_buf: data to be read (dma-safe memory), or NULL
+	@len: size of rx and tx buffers (in bytes)
+	@cs_change: affects chipselect after this transfer completes

debug/spi/spi2uart.c

@@ -0,0 +1,177 @@
+#include <mach/gpio.h>
+#include <mach/iomux.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_device.h>
+#include "wk2xxx.h"
+
+/* global mutex lock */
+static DEFINE_MUTEX(wk2xxxs_reg_lock);
+
+#define GPIO_DRIVER_CS_SUCK
+#ifdef GPIO_DRIVER_CS_SUCK
+#define CS_HIGH 1
+#define CS_LOW 0
+void chip_select_enable(int enable)
+{
+	iomux_set(GPIO0_D7);
+	gpio_set_value(RK30_PIN0_PD7, enable);
+	iomux_set(SPI1_CS0);
+}
+#endif
+
+static int wk2xxx_write_reg(struct spi_device *chip, uint8_t port, uint8_t reg, uint8_t data)
+{
+	struct spi_message msg;
+	uint8_t buffer_w[2];
+	int status;
+	struct spi_transfer index_xfer = {
+		.len            = 2,
+		.cs_change      = 1,
+	};
+	int sub_number;
+
+	sub_number = ((port - 1) << 4);
+
+	mutex_lock(&wk2xxxs_reg_lock);
+
+	spi_message_init(&msg);
+
+	/* 构造控制字节和数据, 参考wk2xxx手册 */
+	buffer_w[0] = sub_number | reg;
+	buffer_w[1] = data;
+
+	/* 设置发送缓冲区 */
+	index_xfer.tx_buf = buffer_w;
+
+	spi_message_add_tail(&index_xfer, &msg);
+#ifdef GPIO_DRIVER_CS_SUCK
+	chip_select_enable(CS_LOW);
+#endif
+	status = spi_sync(chip, &msg);
+	if(status)
+	{
+		printk("spi sync error\n");
+		return status;
+	}
+	udelay(3);
+	mutex_unlock(&wk2xxxs_reg_lock);
+
+#ifdef GPIO_DRIVER_CS_SUCK
+	chip_select_enable(CS_HIGH);
+#endif
+
+	return status;
+}
+
+static int wk2xxx_read_reg(struct spi_device *chip, uint8_t port, uint8_t reg, uint8_t *data)
+{
+	struct spi_message msg;
+	uint8_t buffer_w[2];
+	uint8_t buffer_r[2];
+	int status = 0;
+	int sub_number;
+
+	struct spi_transfer index_xfer = {
+		.len            = 2,
+		.cs_change      = 1,
+	};
+
+	sub_number = ((port - 1) << 4);
+
+	mutex_lock(&wk2xxxs_reg_lock);
+	spi_message_init(&msg);
+	buffer_w[0] = 0x40 | sub_number | reg;
+	buffer_w[1] = 0x00;
+	buffer_r[0] = 0x00;
+	buffer_r[1] = 0x00;
+
+	index_xfer.tx_buf = buffer_w;
+	index_xfer.rx_buf = buffer_r;
+
+	spi_message_add_tail(&index_xfer, &msg);
+
+#ifdef GPIO_DRIVER_CS_SUCK
+	chip_select_enable(CS_LOW);
+#endif
+	status = spi_sync(chip, &msg);
+	if(status)
+	{
+		printk("spi sync error\n");
+		return status;
+	}
+	udelay(3);
+	mutex_unlock(&wk2xxxs_reg_lock);
+
+	/* 读出的数据 */
+	*data = buffer_r[1];
+
+#ifdef GPIO_DRIVER_CS_SUCK
+	chip_select_enable(CS_HIGH);
+#endif
+
+	return 0;
+}
+
+static int wk2xxx_remove(struct spi_device *chip)
+{
+	printk("%s, %d\n", __FUNCTION__, __LINE__);
+
+	return 0;
+}
+
+static int wk2xxx_probe(struct spi_device *chip)
+{
+	int i;
+    unsigned char val = 0;
+
+	printk("%s, %d\n", __FUNCTION__, __LINE__);
+
+	for (i = 0; i < 10; i++)
+	{
+		/* do 10 time read write */
+		wk2xxx_read_reg(chip, WK2XXX_GPORT, WK2XXX_GENA, &val);
+		printk("rval = 0x%x, time %d\n", val, i);
+		if ((val & 0xF0) == 0x30)
+			printk("Nice, :) SPI OK %d time %d\n", val, i);
+         wk2xxx_write_reg(chip, WK2XXX_GPORT, WK2XXX_GENA, i);
+	}
+
+	return 0;
+}
+
+static struct spi_driver wk2xxx_driver = {
+	.driver = {
+		.name           = "wk2xxxspi",
+		.bus            = &spi_bus_type,
+		.owner          = THIS_MODULE,
+	},
+
+	.probe          = wk2xxx_probe,
+	.remove         = wk2xxx_remove,
+};
+
+static int wk2xxx_init(void)
+{
+	int retval;
+	retval = spi_register_driver(&wk2xxx_driver);
+	printk("%s, %d\n", __FUNCTION__, __LINE__);
+	return retval;
+}
+
+static void wk2xxx_exit(void)
+{
+	printk("%s, %d\n", __FUNCTION__, __LINE__);
+	spi_unregister_driver(&wk2xxx_driver);
+}
+
+module_init(wk2xxx_init);
+module_exit(wk2xxx_exit);
+
+MODULE_AUTHOR("zeroway");
+MODULE_DESCRIPTION("wk2xxx spi2uart");
+MODULE_LICENSE("GPL");