1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Driver for the Conexant CX25821 PCIe bridge
4 *
5 * Copyright (C) 2009 Conexant Systems Inc.
6 * Authors <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
7 */
8
9#include <linux/module.h>
10#include "cx25821.h"
11
12/********************* GPIO stuffs *********************/
13void cx25821_set_gpiopin_direction(struct cx25821_dev *dev,
14 int pin_number, int pin_logic_value)
15{
16 int bit = pin_number;
17 u32 gpio_oe_reg = GPIO_LO_OE;
18 u32 gpio_register = 0;
19 u32 value = 0;
20
21 /* Check for valid pinNumber */
22 if (pin_number >= 47)
23 return;
24
25 if (pin_number > 31) {
26 bit = pin_number - 31;
27 gpio_oe_reg = GPIO_HI_OE;
28 }
29 /* Here we will make sure that the GPIOs 0 and 1 are output. keep the
30 * rest as is */
31 gpio_register = cx_read(gpio_oe_reg);
32
33 if (pin_logic_value == 1)
34 value = gpio_register | Set_GPIO_Bit(bit);
35 else
36 value = gpio_register & Clear_GPIO_Bit(bit);
37
38 cx_write(gpio_oe_reg, value);
39}
40EXPORT_SYMBOL(cx25821_set_gpiopin_direction);
41
42static void cx25821_set_gpiopin_logicvalue(struct cx25821_dev *dev,
43 int pin_number, int pin_logic_value)
44{
45 int bit = pin_number;
46 u32 gpio_reg = GPIO_LO;
47 u32 value = 0;
48
49 /* Check for valid pinNumber */
50 if (pin_number >= 47)
51 return;
52
53 /* change to output direction */
54 cx25821_set_gpiopin_direction(dev, pin_number, 0);
55
56 if (pin_number > 31) {
57 bit = pin_number - 31;
58 gpio_reg = GPIO_HI;
59 }
60
61 value = cx_read(gpio_reg);
62
63 if (pin_logic_value == 0)
64 value &= Clear_GPIO_Bit(bit);
65 else
66 value |= Set_GPIO_Bit(bit);
67
68 cx_write(gpio_reg, value);
69}
70
71void cx25821_gpio_init(struct cx25821_dev *dev)
72{
73 if (dev == NULL)
74 return;
75
76 switch (dev->board) {
77 case CX25821_BOARD_CONEXANT_ATHENA10:
78 default:
79 /* set GPIO 5 to select the path for Medusa/Athena */
80 cx25821_set_gpiopin_logicvalue(dev, pin_number: 5, pin_logic_value: 1);
81 msleep(msecs: 20);
82 break;
83 }
84
85}
86

source code of linux/drivers/media/pci/cx25821/cx25821-gpio.c