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
13static 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
26static 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
33static 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
39static 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
66u32 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