1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright(c) 2008 - 2010 Realtek Corporation. All rights reserved.
4  *
5  * Based on the r8180 driver, which is:
6  * Copyright 2004-2005 Andrea Merello <andrea.merello@gmail.com>, et al.
7  *
8  * Contact Information: wlanfae <wlanfae@realtek.com>
9  */
10 #include "rtl_core.h"
11 #include "rtl_eeprom.h"
12 
13 static void _rtl92e_gpio_write_bit(struct net_device *dev, int no, bool val)
14 {
15 	u8 reg = rtl92e_readb(dev, EPROM_CMD);
16 
17 	if (val)
18 		reg |= 1 << no;
19 	else
20 		reg &= ~(1 << no);
21 
22 	rtl92e_writeb(dev, EPROM_CMD, reg);
23 	udelay(EPROM_DELAY);
24 }
25 
26 static bool _rtl92e_gpio_get_bit(struct net_device *dev, int no)
27 {
28 	u8 reg = rtl92e_readb(dev, EPROM_CMD);
29 
30 	return (reg >> no) & 0x1;
31 }
32 
33 static void _rtl92e_eeprom_ck_cycle(struct net_device *dev)
34 {
35 	_rtl92e_gpio_write_bit(dev, EPROM_CK_BIT, 1);
36 	_rtl92e_gpio_write_bit(dev, EPROM_CK_BIT, 0);
37 }
38 
39 static u16 _rtl92e_eeprom_xfer(struct net_device *dev, u16 data, int tx_len)
40 {
41 	u16 ret = 0;
42 	int rx_len = 16;
43 
44 	_rtl92e_gpio_write_bit(dev, EPROM_CS_BIT, 1);
45 	_rtl92e_eeprom_ck_cycle(dev);
46 
47 	while (tx_len--) {
48 		_rtl92e_gpio_write_bit(dev, EPROM_W_BIT,
49 				       (data >> tx_len) & 0x1);
50 		_rtl92e_eeprom_ck_cycle(dev);
51 	}
52 
53 	_rtl92e_gpio_write_bit(dev, EPROM_W_BIT, 0);
54 
55 	while (rx_len--) {
56 		_rtl92e_eeprom_ck_cycle(dev);
57 		ret |= _rtl92e_gpio_get_bit(dev, EPROM_R_BIT) << rx_len;
58 	}
59 
60 	_rtl92e_gpio_write_bit(dev, EPROM_CS_BIT, 0);
61 	_rtl92e_eeprom_ck_cycle(dev);
62 
63 	return ret;
64 }
65 
66 u32 rtl92e_eeprom_read(struct net_device *dev, u32 addr)
67 {
68 	struct r8192_priv *priv = rtllib_priv(dev);
69 	u32 ret = 0;
70 
71 	rtl92e_writeb(dev, EPROM_CMD,
72 		      (EPROM_CMD_PROGRAM << EPROM_CMD_OPERATING_MODE_SHIFT));
73 	udelay(EPROM_DELAY);
74 
75 	/* EEPROM is configured as x16 */
76 	if (priv->epromtype == EEPROM_93C56)
77 		ret = _rtl92e_eeprom_xfer(dev, (addr & 0xFF) | (0x6 << 8), 11);
78 	else
79 		ret = _rtl92e_eeprom_xfer(dev, (addr & 0x3F) | (0x6 << 6), 9);
80 
81 	rtl92e_writeb(dev, EPROM_CMD,
82 		      (EPROM_CMD_NORMAL<<EPROM_CMD_OPERATING_MODE_SHIFT));
83 	return ret;
84 }
85