--- /dev/null
+/*
+ * Realtek RTL8366 SMI interface driver
+ *
+ * Copyright (C) 2009-2010 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/spinlock.h>
+
+#include "rtl8366_smi.h"
+
+#define RTL8366_SMI_ACK_RETRY_COUNT 5
+#define RTL8366_SMI_CLK_DELAY 10 /* nsec */
+
+static inline void rtl8366_smi_clk_delay(struct rtl8366_smi *smi)
+{
+ ndelay(RTL8366_SMI_CLK_DELAY);
+}
+
+static void rtl8366_smi_start(struct rtl8366_smi *smi)
+{
+ unsigned int sda = smi->gpio_sda;
+ unsigned int sck = smi->gpio_sck;
+
+ /*
+ * Set GPIO pins to output mode, with initial state:
+ * SCK = 0, SDA = 1
+ */
+ gpio_direction_output(sck, 0);
+ gpio_direction_output(sda, 1);
+ rtl8366_smi_clk_delay(smi);
+
+ /* CLK 1: 0 -> 1, 1 -> 0 */
+ gpio_set_value(sck, 1);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sck, 0);
+ rtl8366_smi_clk_delay(smi);
+
+ /* CLK 2: */
+ gpio_set_value(sck, 1);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sda, 0);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sck, 0);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sda, 1);
+}
+
+static void rtl8366_smi_stop(struct rtl8366_smi *smi)
+{
+ unsigned int sda = smi->gpio_sda;
+ unsigned int sck = smi->gpio_sck;
+
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sda, 0);
+ gpio_set_value(sck, 1);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sda, 1);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sck, 1);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sck, 0);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sck, 1);
+
+ /* add a click */
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sck, 0);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sck, 1);
+
+ /* set GPIO pins to input mode */
+ gpio_direction_input(sda);
+ gpio_direction_input(sck);
+}
+
+static void rtl8366_smi_write_bits(struct rtl8366_smi *smi, u32 data, u32 len)
+{
+ unsigned int sda = smi->gpio_sda;
+ unsigned int sck = smi->gpio_sck;
+
+ for (; len > 0; len--) {
+ rtl8366_smi_clk_delay(smi);
+
+ /* prepare data */
+ if ( data & ( 1 << (len - 1)) )
+ gpio_set_value(sda, 1);
+ else
+ gpio_set_value(sda, 0);
+ rtl8366_smi_clk_delay(smi);
+
+ /* clocking */
+ gpio_set_value(sck, 1);
+ rtl8366_smi_clk_delay(smi);
+ gpio_set_value(sck, 0);
+ }
+}
+
+static void rtl8366_smi_read_bits(struct rtl8366_smi *smi, u32 len, u32 *data)
+{
+ unsigned int sda = smi->gpio_sda;
+ unsigned int sck = smi->gpio_sck;
+
+ gpio_direction_input(sda);
+
+ for (*data = 0; len > 0; len--) {
+ u32 u;
+
+ rtl8366_smi_clk_delay(smi);
+
+ /* clocking */
+ gpio_set_value(sck, 1);
+ rtl8366_smi_clk_delay(smi);
+ u = gpio_get_value(sda);
+ gpio_set_value(sck, 0);
+
+ *data |= (u << (len - 1));
+ }
+
+ gpio_direction_output(sda, 0);
+}
+
+static int rtl8366_smi_wait_for_ack(struct rtl8366_smi *smi)
+{
+ int retry_cnt;
+
+ retry_cnt = 0;
+ do {
+ u32 ack;
+
+ rtl8366_smi_read_bits(smi, 1, &ack);
+ if (ack == 0)
+ break;
+
+ if (++retry_cnt > RTL8366_SMI_ACK_RETRY_COUNT)
+ return -EIO;
+ } while (1);
+
+ return 0;
+}
+
+static int rtl8366_smi_write_byte(struct rtl8366_smi *smi, u8 data)
+{
+ rtl8366_smi_write_bits(smi, data, 8);
+ return rtl8366_smi_wait_for_ack(smi);
+}
+
+static int rtl8366_smi_read_byte0(struct rtl8366_smi *smi, u8 *data)
+{
+ u32 t;
+
+ /* read data */
+ rtl8366_smi_read_bits(smi, 8, &t);
+ *data = (t & 0xff);
+
+ /* send an ACK */
+ rtl8366_smi_write_bits(smi, 0x00, 1);
+
+ return 0;
+}
+
+static int rtl8366_smi_read_byte1(struct rtl8366_smi *smi, u8 *data)
+{
+ u32 t;
+
+ /* read data */
+ rtl8366_smi_read_bits(smi, 8, &t);
+ *data = (t & 0xff);
+
+ /* send an ACK */
+ rtl8366_smi_write_bits(smi, 0x01, 1);
+
+ return 0;
+}
+
+int rtl8366_smi_read_reg(struct rtl8366_smi *smi, u32 addr, u32 *data)
+{
+ unsigned long flags;
+ u8 lo = 0;
+ u8 hi = 0;
+ int ret;
+
+ spin_lock_irqsave(&smi->lock, flags);
+
+ rtl8366_smi_start(smi);
+
+ /* send READ command */
+ ret = rtl8366_smi_write_byte(smi, 0x0a << 4 | 0x04 << 1 | 0x01);
+ if (ret)
+ goto out;
+
+ /* set ADDR[7:0] */
+ ret = rtl8366_smi_write_byte(smi, addr & 0xff);
+ if (ret)
+ goto out;
+
+ /* set ADDR[15:8] */
+ ret = rtl8366_smi_write_byte(smi, addr >> 8);
+ if (ret)
+ goto out;
+
+ /* read DATA[7:0] */
+ rtl8366_smi_read_byte0(smi, &lo);
+ /* read DATA[15:8] */
+ rtl8366_smi_read_byte1(smi, &hi);
+
+ *data = ((u32) lo) | (((u32) hi) << 8);
+
+ ret = 0;
+
+ out:
+ rtl8366_smi_stop(smi);
+ spin_unlock_irqrestore(&smi->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rtl8366_smi_read_reg);
+
+int rtl8366_smi_write_reg(struct rtl8366_smi *smi, u32 addr, u32 data)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&smi->lock, flags);
+
+ rtl8366_smi_start(smi);
+
+ /* send WRITE command */
+ ret = rtl8366_smi_write_byte(smi, 0x0a << 4 | 0x04 << 1 | 0x00);
+ if (ret)
+ goto out;
+
+ /* set ADDR[7:0] */
+ ret = rtl8366_smi_write_byte(smi, addr & 0xff);
+ if (ret)
+ goto out;
+
+ /* set ADDR[15:8] */
+ ret = rtl8366_smi_write_byte(smi, addr >> 8);
+ if (ret)
+ goto out;
+
+ /* write DATA[7:0] */
+ ret = rtl8366_smi_write_byte(smi, data & 0xff);
+ if (ret)
+ goto out;
+
+ /* write DATA[15:8] */
+ ret = rtl8366_smi_write_byte(smi, data >> 8);
+ if (ret)
+ goto out;
+
+ ret = 0;
+
+ out:
+ rtl8366_smi_stop(smi);
+ spin_unlock_irqrestore(&smi->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(rtl8366_smi_write_reg);
+
+int rtl8366_smi_init(struct rtl8366_smi *smi)
+{
+ int err;
+
+ if (!smi->parent)
+ return -EINVAL;
+
+ err = gpio_request(smi->gpio_sda, dev_name(smi->parent));
+ if (err) {
+ dev_err(smi->parent, "gpio_request failed for %u, err=%d\n",
+ smi->gpio_sda, err);
+ goto err_out;
+ }
+
+ err = gpio_request(smi->gpio_sck, dev_name(smi->parent));
+ if (err) {
+ dev_err(smi->parent, "gpio_request failed for %u, err=%d\n",
+ smi->gpio_sck, err);
+ goto err_free_sda;
+ }
+
+ spin_lock_init(&smi->lock);
+
+ dev_info(smi->parent, "using GPIO pins %u (SDA) and %u (SCK)\n",
+ smi->gpio_sda, smi->gpio_sck);
+
+ return 0;
+
+ err_free_sda:
+ gpio_free(smi->gpio_sda);
+ err_out:
+ return err;
+}
+EXPORT_SYMBOL_GPL(rtl8366_smi_init);
+
+void rtl8366_smi_cleanup(struct rtl8366_smi *smi)
+{
+ gpio_free(smi->gpio_sck);
+ gpio_free(smi->gpio_sda);
+}
+EXPORT_SYMBOL_GPL(rtl8366_smi_cleanup);
+
+MODULE_DESCRIPTION("Realtek RTL8366 SMI interface driver");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_LICENSE("GPL v2");
projects / 10.03 / openwrt.git / blobdiff