LXR linux/drivers/pcmcia/max1600.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * MAX1600 PCMCIA power switch library
   4 *
   5 * Copyright (C) 2016 Russell King
   6 */
   7#include <linux/device.h>
   8#include <linux/module.h>
   9#include <linux/gpio/consumer.h>
  10#include <linux/slab.h>
  11#include "max1600.h"
  12
  13static const char *max1600_gpio_name[2][MAX1600_GPIO_MAX] = {
  14        { "a0vcc", "a1vcc", "a0vpp", "a1vpp" },
  15        { "b0vcc", "b1vcc", "b0vpp", "b1vpp" },
  16};
  17
  18int max1600_init(struct device *dev, struct max1600 **ptr,
  19        unsigned int channel, unsigned int code)
  20{
  21        struct max1600 *m;
  22        int chan;
  23        int i;
  24
  25        switch (channel) {
  26        case MAX1600_CHAN_A:
  27                chan = 0;
  28                break;
  29        case MAX1600_CHAN_B:
  30                chan = 1;
  31                break;
  32        default:
  33                return -EINVAL;
  34        }
  35
  36        if (code != MAX1600_CODE_LOW && code != MAX1600_CODE_HIGH)
  37                return -EINVAL;
  38
  39        m = devm_kzalloc(dev, sizeof(*m), GFP_KERNEL);
  40        if (!m)
  41                return -ENOMEM;
  42
  43        m->dev = dev;
  44        m->code = code;
  45
  46        for (i = 0; i < MAX1600_GPIO_MAX; i++) {
  47                const char *name;
  48
  49                name = max1600_gpio_name[chan][i];
  50                if (i != MAX1600_GPIO_0VPP) {
  51                        m->gpio[i] = devm_gpiod_get(dev, name, GPIOD_OUT_LOW);
  52                } else {
  53                        m->gpio[i] = devm_gpiod_get_optional(dev, name,
  54                                                             GPIOD_OUT_LOW);
  55                        if (!m->gpio[i])
  56                                break;
  57                }
  58                if (IS_ERR(m->gpio[i]))
  59                        return PTR_ERR(m->gpio[i]);
  60        }
  61
  62        *ptr = m;
  63
  64        return 0;
  65}
  66EXPORT_SYMBOL_GPL(max1600_init);
  67
  68int max1600_configure(struct max1600 *m, unsigned int vcc, unsigned int vpp)
  69{
  70        DECLARE_BITMAP(values, MAX1600_GPIO_MAX) = { 0, };
  71        int n = MAX1600_GPIO_0VPP;
  72
  73        if (m->gpio[MAX1600_GPIO_0VPP]) {
  74                if (vpp == 0) {
  75                        __assign_bit(MAX1600_GPIO_0VPP, values, 0);
  76                        __assign_bit(MAX1600_GPIO_1VPP, values, 0);
  77                } else if (vpp == 120) {
  78                        __assign_bit(MAX1600_GPIO_0VPP, values, 0);
  79                        __assign_bit(MAX1600_GPIO_1VPP, values, 1);
  80                } else if (vpp == vcc) {
  81                        __assign_bit(MAX1600_GPIO_0VPP, values, 1);
  82                        __assign_bit(MAX1600_GPIO_1VPP, values, 0);
  83                } else {
  84                        dev_err(m->dev, "unrecognised Vpp %u.%uV\n",
  85                                vpp / 10, vpp % 10);
  86                        return -EINVAL;
  87                }
  88                n = MAX1600_GPIO_MAX;
  89        } else if (vpp != vcc && vpp != 0) {
  90                dev_err(m->dev, "no VPP control\n");
  91                return -EINVAL;
  92        }
  93
  94        if (vcc == 0) {
  95                __assign_bit(MAX1600_GPIO_0VCC, values, 0);
  96                __assign_bit(MAX1600_GPIO_1VCC, values, 0);
  97        } else if (vcc == 33) { /* VY */
  98                __assign_bit(MAX1600_GPIO_0VCC, values, 1);
  99                __assign_bit(MAX1600_GPIO_1VCC, values, 0);
 100        } else if (vcc == 50) { /* VX */
 101                __assign_bit(MAX1600_GPIO_0VCC, values, 0);
 102                __assign_bit(MAX1600_GPIO_1VCC, values, 1);
 103        } else {
 104                dev_err(m->dev, "unrecognised Vcc %u.%uV\n",
 105                        vcc / 10, vcc % 10);
 106                return -EINVAL;
 107        }
 108
 109        if (m->code == MAX1600_CODE_HIGH) {
 110                /*
 111                 * Cirrus mode appears to be the same as Intel mode,
 112                 * except the VCC pins are inverted.
 113                 */
 114                __change_bit(MAX1600_GPIO_0VCC, values);
 115                __change_bit(MAX1600_GPIO_1VCC, values);
 116        }
 117
 118        return gpiod_set_array_value_cansleep(n, m->gpio, NULL, values);
 119}
 120EXPORT_SYMBOL_GPL(max1600_configure);
 121
 122MODULE_LICENSE("GPL v2");
 123