+++ /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 / openwrt.git / blobdiff