xref: /linux/drivers/media/pci/cx25821/cx25821-gpio.c (revision c0b2826aa02a0747c3016457b9c1917ba14d0655)
1 /*
2  *  Driver for the Conexant CX25821 PCIe bridge
3  *
4  *  Copyright (C) 2009 Conexant Systems Inc.
5  *  Authors  <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; either version 2 of the License, or
10  *  (at your option) any later version.
11  *
12  *  This program is distributed in the hope that it will be useful,
13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *
16  *  GNU General Public License for more details.
17  */
18 
19 #include <linux/module.h>
20 #include "cx25821.h"
21 
22 /********************* GPIO stuffs *********************/
23 void cx25821_set_gpiopin_direction(struct cx25821_dev *dev,
24 				   int pin_number, int pin_logic_value)
25 {
26 	int bit = pin_number;
27 	u32 gpio_oe_reg = GPIO_LO_OE;
28 	u32 gpio_register = 0;
29 	u32 value = 0;
30 
31 	/* Check for valid pinNumber */
32 	if (pin_number >= 47)
33 		return;
34 
35 	if (pin_number > 31) {
36 		bit = pin_number - 31;
37 		gpio_oe_reg = GPIO_HI_OE;
38 	}
39 	/* Here we will make sure that the GPIOs 0 and 1 are output. keep the
40 	 * rest as is */
41 	gpio_register = cx_read(gpio_oe_reg);
42 
43 	if (pin_logic_value == 1)
44 		value = gpio_register | Set_GPIO_Bit(bit);
45 	else
46 		value = gpio_register & Clear_GPIO_Bit(bit);
47 
48 	cx_write(gpio_oe_reg, value);
49 }
50 EXPORT_SYMBOL(cx25821_set_gpiopin_direction);
51 
52 static void cx25821_set_gpiopin_logicvalue(struct cx25821_dev *dev,
53 					   int pin_number, int pin_logic_value)
54 {
55 	int bit = pin_number;
56 	u32 gpio_reg = GPIO_LO;
57 	u32 value = 0;
58 
59 	/* Check for valid pinNumber */
60 	if (pin_number >= 47)
61 		return;
62 
63 	/* change to output direction */
64 	cx25821_set_gpiopin_direction(dev, pin_number, 0);
65 
66 	if (pin_number > 31) {
67 		bit = pin_number - 31;
68 		gpio_reg = GPIO_HI;
69 	}
70 
71 	value = cx_read(gpio_reg);
72 
73 	if (pin_logic_value == 0)
74 		value &= Clear_GPIO_Bit(bit);
75 	else
76 		value |= Set_GPIO_Bit(bit);
77 
78 	cx_write(gpio_reg, value);
79 }
80 
81 void cx25821_gpio_init(struct cx25821_dev *dev)
82 {
83 	if (dev == NULL)
84 		return;
85 
86 	switch (dev->board) {
87 	case CX25821_BOARD_CONEXANT_ATHENA10:
88 	default:
89 		/* set GPIO 5 to select the path for Medusa/Athena */
90 		cx25821_set_gpiopin_logicvalue(dev, 5, 1);
91 		msleep(20);
92 		break;
93 	}
94 
95 }
96