5530def54e5bbf8a08be34e3ce4ea2534a8802da
[~shefty/rdma-dev.git] / drivers / mmc / host / of_mmc_spi.c
1 /*
2  * OpenFirmware bindings for the MMC-over-SPI driver
3  *
4  * Copyright (c) MontaVista Software, Inc. 2008.
5  *
6  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7  *
8  * This program is free software; you can redistribute  it and/or modify it
9  * under  the terms of  the GNU General  Public License as published by the
10  * Free Software Foundation;  either version 2 of the  License, or (at your
11  * option) any later version.
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/device.h>
17 #include <linux/slab.h>
18 #include <linux/gpio.h>
19 #include <linux/of.h>
20 #include <linux/of_gpio.h>
21 #include <linux/spi/spi.h>
22 #include <linux/spi/mmc_spi.h>
23 #include <linux/mmc/core.h>
24 #include <linux/mmc/host.h>
25
26 MODULE_LICENSE("GPL");
27
28 enum {
29         CD_GPIO = 0,
30         WP_GPIO,
31         NUM_GPIOS,
32 };
33
34 struct of_mmc_spi {
35         int gpios[NUM_GPIOS];
36         bool alow_gpios[NUM_GPIOS];
37         int detect_irq;
38         struct mmc_spi_platform_data pdata;
39 };
40
41 static struct of_mmc_spi *to_of_mmc_spi(struct device *dev)
42 {
43         return container_of(dev->platform_data, struct of_mmc_spi, pdata);
44 }
45
46 static int of_mmc_spi_read_gpio(struct device *dev, int gpio_num)
47 {
48         struct of_mmc_spi *oms = to_of_mmc_spi(dev);
49         bool active_low = oms->alow_gpios[gpio_num];
50         bool value = gpio_get_value(oms->gpios[gpio_num]);
51
52         return active_low ^ value;
53 }
54
55 static int of_mmc_spi_get_cd(struct device *dev)
56 {
57         return of_mmc_spi_read_gpio(dev, CD_GPIO);
58 }
59
60 static int of_mmc_spi_get_ro(struct device *dev)
61 {
62         return of_mmc_spi_read_gpio(dev, WP_GPIO);
63 }
64
65 static int of_mmc_spi_init(struct device *dev,
66                            irqreturn_t (*irqhandler)(int, void *), void *mmc)
67 {
68         struct of_mmc_spi *oms = to_of_mmc_spi(dev);
69
70         return request_threaded_irq(oms->detect_irq, NULL, irqhandler, 0,
71                                     dev_name(dev), mmc);
72 }
73
74 static void of_mmc_spi_exit(struct device *dev, void *mmc)
75 {
76         struct of_mmc_spi *oms = to_of_mmc_spi(dev);
77
78         free_irq(oms->detect_irq, mmc);
79 }
80
81 struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
82 {
83         struct device *dev = &spi->dev;
84         struct device_node *np = dev->of_node;
85         struct of_mmc_spi *oms;
86         const u32 *voltage_ranges;
87         int num_ranges;
88         int i;
89         int ret = -EINVAL;
90
91         if (dev->platform_data || !np)
92                 return dev->platform_data;
93
94         oms = kzalloc(sizeof(*oms), GFP_KERNEL);
95         if (!oms)
96                 return NULL;
97
98         voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
99         num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
100         if (!voltage_ranges || !num_ranges) {
101                 dev_err(dev, "OF: voltage-ranges unspecified\n");
102                 goto err_ocr;
103         }
104
105         for (i = 0; i < num_ranges; i++) {
106                 const int j = i * 2;
107                 u32 mask;
108
109                 mask = mmc_vddrange_to_ocrmask(voltage_ranges[j],
110                                                voltage_ranges[j + 1]);
111                 if (!mask) {
112                         ret = -EINVAL;
113                         dev_err(dev, "OF: voltage-range #%d is invalid\n", i);
114                         goto err_ocr;
115                 }
116                 oms->pdata.ocr_mask |= mask;
117         }
118
119         for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
120                 enum of_gpio_flags gpio_flags;
121
122                 oms->gpios[i] = of_get_gpio_flags(np, i, &gpio_flags);
123                 if (!gpio_is_valid(oms->gpios[i]))
124                         continue;
125
126                 ret = gpio_request(oms->gpios[i], dev_name(dev));
127                 if (ret < 0) {
128                         oms->gpios[i] = -EINVAL;
129                         continue;
130                 }
131
132                 if (gpio_flags & OF_GPIO_ACTIVE_LOW)
133                         oms->alow_gpios[i] = true;
134         }
135
136         if (gpio_is_valid(oms->gpios[CD_GPIO]))
137                 oms->pdata.get_cd = of_mmc_spi_get_cd;
138         if (gpio_is_valid(oms->gpios[WP_GPIO]))
139                 oms->pdata.get_ro = of_mmc_spi_get_ro;
140
141         oms->detect_irq = irq_of_parse_and_map(np, 0);
142         if (oms->detect_irq != NO_IRQ) {
143                 oms->pdata.init = of_mmc_spi_init;
144                 oms->pdata.exit = of_mmc_spi_exit;
145         } else {
146                 oms->pdata.caps |= MMC_CAP_NEEDS_POLL;
147         }
148
149         dev->platform_data = &oms->pdata;
150         return dev->platform_data;
151 err_ocr:
152         kfree(oms);
153         return NULL;
154 }
155 EXPORT_SYMBOL(mmc_spi_get_pdata);
156
157 void mmc_spi_put_pdata(struct spi_device *spi)
158 {
159         struct device *dev = &spi->dev;
160         struct device_node *np = dev->of_node;
161         struct of_mmc_spi *oms = to_of_mmc_spi(dev);
162         int i;
163
164         if (!dev->platform_data || !np)
165                 return;
166
167         for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
168                 if (gpio_is_valid(oms->gpios[i]))
169                         gpio_free(oms->gpios[i]);
170         }
171         kfree(oms);
172         dev->platform_data = NULL;
173 }
174 EXPORT_SYMBOL(mmc_spi_put_pdata);