2 * Realtek RTL8366 SMI interface driver
4 * Copyright (C) 2009-2010 Gabor Juhos <juhosg@openwrt.org>
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation.
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/device.h>
14 #include <linux/delay.h>
15 #include <linux/gpio.h>
16 #include <linux/spinlock.h>
17 #include <linux/skbuff.h>
19 #include "rtl8366_smi.h"
21 #define RTL8366_SMI_ACK_RETRY_COUNT 5
22 #define RTL8366_SMI_CLK_DELAY 10 /* nsec */
24 static inline void rtl8366_smi_clk_delay(struct rtl8366_smi *smi)
26 ndelay(RTL8366_SMI_CLK_DELAY);
29 static void rtl8366_smi_start(struct rtl8366_smi *smi)
31 unsigned int sda = smi->gpio_sda;
32 unsigned int sck = smi->gpio_sck;
35 * Set GPIO pins to output mode, with initial state:
38 gpio_direction_output(sck, 0);
39 gpio_direction_output(sda, 1);
40 rtl8366_smi_clk_delay(smi);
42 /* CLK 1: 0 -> 1, 1 -> 0 */
43 gpio_set_value(sck, 1);
44 rtl8366_smi_clk_delay(smi);
45 gpio_set_value(sck, 0);
46 rtl8366_smi_clk_delay(smi);
49 gpio_set_value(sck, 1);
50 rtl8366_smi_clk_delay(smi);
51 gpio_set_value(sda, 0);
52 rtl8366_smi_clk_delay(smi);
53 gpio_set_value(sck, 0);
54 rtl8366_smi_clk_delay(smi);
55 gpio_set_value(sda, 1);
58 static void rtl8366_smi_stop(struct rtl8366_smi *smi)
60 unsigned int sda = smi->gpio_sda;
61 unsigned int sck = smi->gpio_sck;
63 rtl8366_smi_clk_delay(smi);
64 gpio_set_value(sda, 0);
65 gpio_set_value(sck, 1);
66 rtl8366_smi_clk_delay(smi);
67 gpio_set_value(sda, 1);
68 rtl8366_smi_clk_delay(smi);
69 gpio_set_value(sck, 1);
70 rtl8366_smi_clk_delay(smi);
71 gpio_set_value(sck, 0);
72 rtl8366_smi_clk_delay(smi);
73 gpio_set_value(sck, 1);
76 rtl8366_smi_clk_delay(smi);
77 gpio_set_value(sck, 0);
78 rtl8366_smi_clk_delay(smi);
79 gpio_set_value(sck, 1);
81 /* set GPIO pins to input mode */
82 gpio_direction_input(sda);
83 gpio_direction_input(sck);
86 static void rtl8366_smi_write_bits(struct rtl8366_smi *smi, u32 data, u32 len)
88 unsigned int sda = smi->gpio_sda;
89 unsigned int sck = smi->gpio_sck;
91 for (; len > 0; len--) {
92 rtl8366_smi_clk_delay(smi);
95 gpio_set_value(sda, !!(data & ( 1 << (len - 1))));
96 rtl8366_smi_clk_delay(smi);
99 gpio_set_value(sck, 1);
100 rtl8366_smi_clk_delay(smi);
101 gpio_set_value(sck, 0);
105 static void rtl8366_smi_read_bits(struct rtl8366_smi *smi, u32 len, u32 *data)
107 unsigned int sda = smi->gpio_sda;
108 unsigned int sck = smi->gpio_sck;
110 gpio_direction_input(sda);
112 for (*data = 0; len > 0; len--) {
115 rtl8366_smi_clk_delay(smi);
118 gpio_set_value(sck, 1);
119 rtl8366_smi_clk_delay(smi);
120 u = !!gpio_get_value(sda);
121 gpio_set_value(sck, 0);
123 *data |= (u << (len - 1));
126 gpio_direction_output(sda, 0);
129 static int rtl8366_smi_wait_for_ack(struct rtl8366_smi *smi)
137 rtl8366_smi_read_bits(smi, 1, &ack);
141 if (++retry_cnt > RTL8366_SMI_ACK_RETRY_COUNT)
148 static int rtl8366_smi_write_byte(struct rtl8366_smi *smi, u8 data)
150 rtl8366_smi_write_bits(smi, data, 8);
151 return rtl8366_smi_wait_for_ack(smi);
154 static int rtl8366_smi_read_byte0(struct rtl8366_smi *smi, u8 *data)
159 rtl8366_smi_read_bits(smi, 8, &t);
163 rtl8366_smi_write_bits(smi, 0x00, 1);
168 static int rtl8366_smi_read_byte1(struct rtl8366_smi *smi, u8 *data)
173 rtl8366_smi_read_bits(smi, 8, &t);
177 rtl8366_smi_write_bits(smi, 0x01, 1);
182 int rtl8366_smi_read_reg(struct rtl8366_smi *smi, u32 addr, u32 *data)
189 spin_lock_irqsave(&smi->lock, flags);
191 rtl8366_smi_start(smi);
193 /* send READ command */
194 ret = rtl8366_smi_write_byte(smi, 0x0a << 4 | 0x04 << 1 | 0x01);
199 ret = rtl8366_smi_write_byte(smi, addr & 0xff);
204 ret = rtl8366_smi_write_byte(smi, addr >> 8);
209 rtl8366_smi_read_byte0(smi, &lo);
210 /* read DATA[15:8] */
211 rtl8366_smi_read_byte1(smi, &hi);
213 *data = ((u32) lo) | (((u32) hi) << 8);
218 rtl8366_smi_stop(smi);
219 spin_unlock_irqrestore(&smi->lock, flags);
223 EXPORT_SYMBOL_GPL(rtl8366_smi_read_reg);
225 int rtl8366_smi_write_reg(struct rtl8366_smi *smi, u32 addr, u32 data)
230 spin_lock_irqsave(&smi->lock, flags);
232 rtl8366_smi_start(smi);
234 /* send WRITE command */
235 ret = rtl8366_smi_write_byte(smi, 0x0a << 4 | 0x04 << 1 | 0x00);
240 ret = rtl8366_smi_write_byte(smi, addr & 0xff);
245 ret = rtl8366_smi_write_byte(smi, addr >> 8);
249 /* write DATA[7:0] */
250 ret = rtl8366_smi_write_byte(smi, data & 0xff);
254 /* write DATA[15:8] */
255 ret = rtl8366_smi_write_byte(smi, data >> 8);
262 rtl8366_smi_stop(smi);
263 spin_unlock_irqrestore(&smi->lock, flags);
267 EXPORT_SYMBOL_GPL(rtl8366_smi_write_reg);
269 int rtl8366_smi_rmwr(struct rtl8366_smi *smi, u32 addr, u32 mask, u32 data)
274 err = rtl8366_smi_read_reg(smi, addr, &t);
278 err = rtl8366_smi_write_reg(smi, addr, (t & ~mask) | data);
282 EXPORT_SYMBOL_GPL(rtl8366_smi_rmwr);
284 static int rtl8366_smi_mii_init(struct rtl8366_smi *smi)
289 smi->mii_bus = mdiobus_alloc();
290 if (smi->mii_bus == NULL) {
295 smi->mii_bus->priv = (void *) smi;
296 smi->mii_bus->name = dev_name(smi->parent);
297 smi->mii_bus->read = smi->ops->mii_read;
298 smi->mii_bus->write = smi->ops->mii_write;
299 snprintf(smi->mii_bus->id, MII_BUS_ID_SIZE, "%s",
300 dev_name(smi->parent));
301 smi->mii_bus->parent = smi->parent;
302 smi->mii_bus->phy_mask = ~(0x1f);
303 smi->mii_bus->irq = smi->mii_irq;
304 for (i = 0; i < PHY_MAX_ADDR; i++)
305 smi->mii_irq[i] = PHY_POLL;
307 ret = mdiobus_register(smi->mii_bus);
314 mdiobus_free(smi->mii_bus);
319 static void rtl8366_smi_mii_cleanup(struct rtl8366_smi *smi)
321 mdiobus_unregister(smi->mii_bus);
322 mdiobus_free(smi->mii_bus);
325 int rtl8366_smi_init(struct rtl8366_smi *smi)
335 err = gpio_request(smi->gpio_sda, dev_name(smi->parent));
337 dev_err(smi->parent, "gpio_request failed for %u, err=%d\n",
342 err = gpio_request(smi->gpio_sck, dev_name(smi->parent));
344 dev_err(smi->parent, "gpio_request failed for %u, err=%d\n",
349 spin_lock_init(&smi->lock);
351 dev_info(smi->parent, "using GPIO pins %u (SDA) and %u (SCK)\n",
352 smi->gpio_sda, smi->gpio_sck);
354 err = smi->ops->detect(smi);
356 dev_err(smi->parent, "chip detection failed, err=%d\n", err);
360 err = rtl8366_smi_mii_init(smi);
367 gpio_free(smi->gpio_sck);
369 gpio_free(smi->gpio_sda);
373 EXPORT_SYMBOL_GPL(rtl8366_smi_init);
375 void rtl8366_smi_cleanup(struct rtl8366_smi *smi)
377 rtl8366_smi_mii_cleanup(smi);
378 gpio_free(smi->gpio_sck);
379 gpio_free(smi->gpio_sda);
381 EXPORT_SYMBOL_GPL(rtl8366_smi_cleanup);
383 MODULE_DESCRIPTION("Realtek RTL8366 SMI interface driver");
384 MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
385 MODULE_LICENSE("GPL v2");