mirror of https://github.com/hak5/openwrt.git
313 lines
6.2 KiB
C
313 lines
6.2 KiB
C
/*
|
|
* 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 */
|
|
gpio_set_value(sda, !!(data & ( 1 << (len - 1))));
|
|
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");
|