drivers/media/pci/cx25821/cx25821-gpio.c

   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 *********************/
  13 void 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 }
  40 EXPORT_SYMBOL(cx25821_set_gpiopin_direction);
  41
  42 static 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
  71 void 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, 5, 1);
  81                 msleep(20);
  82                 break;
  83         }
  84
  85 }