| Russell King | bebdf98 | 2018-11-28 13:57:23 +0000 | [diff] [blame] | 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 | |
| 13 | static const char *max1600_gpio_name[2][MAX1600_GPIO_MAX] = { |
| 14 | { "a0vcc", "a1vcc", "a0vpp", "a1vpp" }, |
| 15 | { "b0vcc", "b1vcc", "b0vpp", "b1vpp" }, |
| 16 | }; |
| 17 | |
| 18 | int 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 | } |
| 66 | EXPORT_SYMBOL_GPL(max1600_init); |
| 67 | |
| 68 | int 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 | } |
| 120 | EXPORT_SYMBOL_GPL(max1600_configure); |
| 121 | |
| 122 | MODULE_LICENSE("GPL v2"); |