xref: /openbmc/linux/drivers/mmc/host/of_mmc_spi.c (revision 0da85d1e)
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/irq.h>
19 #include <linux/gpio.h>
20 #include <linux/of.h>
21 #include <linux/of_gpio.h>
22 #include <linux/of_irq.h>
23 #include <linux/spi/spi.h>
24 #include <linux/spi/mmc_spi.h>
25 #include <linux/mmc/core.h>
26 #include <linux/mmc/host.h>
27 
28 /* For archs that don't support NO_IRQ (such as mips), provide a dummy value */
29 #ifndef NO_IRQ
30 #define NO_IRQ 0
31 #endif
32 
33 MODULE_LICENSE("GPL");
34 
35 enum {
36 	CD_GPIO = 0,
37 	WP_GPIO,
38 	NUM_GPIOS,
39 };
40 
41 struct of_mmc_spi {
42 	int gpios[NUM_GPIOS];
43 	bool alow_gpios[NUM_GPIOS];
44 	int detect_irq;
45 	struct mmc_spi_platform_data pdata;
46 };
47 
48 static struct of_mmc_spi *to_of_mmc_spi(struct device *dev)
49 {
50 	return container_of(dev->platform_data, struct of_mmc_spi, pdata);
51 }
52 
53 static int of_mmc_spi_init(struct device *dev,
54 			   irqreturn_t (*irqhandler)(int, void *), void *mmc)
55 {
56 	struct of_mmc_spi *oms = to_of_mmc_spi(dev);
57 
58 	return request_threaded_irq(oms->detect_irq, NULL, irqhandler, 0,
59 				    dev_name(dev), mmc);
60 }
61 
62 static void of_mmc_spi_exit(struct device *dev, void *mmc)
63 {
64 	struct of_mmc_spi *oms = to_of_mmc_spi(dev);
65 
66 	free_irq(oms->detect_irq, mmc);
67 }
68 
69 struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
70 {
71 	struct device *dev = &spi->dev;
72 	struct device_node *np = dev->of_node;
73 	struct of_mmc_spi *oms;
74 	const u32 *voltage_ranges;
75 	int num_ranges;
76 	int i;
77 	int ret = -EINVAL;
78 
79 	if (dev->platform_data || !np)
80 		return dev->platform_data;
81 
82 	oms = kzalloc(sizeof(*oms), GFP_KERNEL);
83 	if (!oms)
84 		return NULL;
85 
86 	voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
87 	num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
88 	if (!voltage_ranges || !num_ranges) {
89 		dev_err(dev, "OF: voltage-ranges unspecified\n");
90 		goto err_ocr;
91 	}
92 
93 	for (i = 0; i < num_ranges; i++) {
94 		const int j = i * 2;
95 		u32 mask;
96 
97 		mask = mmc_vddrange_to_ocrmask(be32_to_cpu(voltage_ranges[j]),
98 					       be32_to_cpu(voltage_ranges[j + 1]));
99 		if (!mask) {
100 			ret = -EINVAL;
101 			dev_err(dev, "OF: voltage-range #%d is invalid\n", i);
102 			goto err_ocr;
103 		}
104 		oms->pdata.ocr_mask |= mask;
105 	}
106 
107 	for (i = 0; i < ARRAY_SIZE(oms->gpios); i++) {
108 		enum of_gpio_flags gpio_flags;
109 
110 		oms->gpios[i] = of_get_gpio_flags(np, i, &gpio_flags);
111 		if (!gpio_is_valid(oms->gpios[i]))
112 			continue;
113 
114 		if (gpio_flags & OF_GPIO_ACTIVE_LOW)
115 			oms->alow_gpios[i] = true;
116 	}
117 
118 	if (gpio_is_valid(oms->gpios[CD_GPIO])) {
119 		oms->pdata.cd_gpio = oms->gpios[CD_GPIO];
120 		oms->pdata.flags |= MMC_SPI_USE_CD_GPIO;
121 		if (!oms->alow_gpios[CD_GPIO])
122 			oms->pdata.caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
123 	}
124 	if (gpio_is_valid(oms->gpios[WP_GPIO])) {
125 		oms->pdata.ro_gpio = oms->gpios[WP_GPIO];
126 		oms->pdata.flags |= MMC_SPI_USE_RO_GPIO;
127 		if (!oms->alow_gpios[WP_GPIO])
128 			oms->pdata.caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
129 	}
130 
131 	oms->detect_irq = irq_of_parse_and_map(np, 0);
132 	if (oms->detect_irq != 0) {
133 		oms->pdata.init = of_mmc_spi_init;
134 		oms->pdata.exit = of_mmc_spi_exit;
135 	} else {
136 		oms->pdata.caps |= MMC_CAP_NEEDS_POLL;
137 	}
138 
139 	dev->platform_data = &oms->pdata;
140 	return dev->platform_data;
141 err_ocr:
142 	kfree(oms);
143 	return NULL;
144 }
145 EXPORT_SYMBOL(mmc_spi_get_pdata);
146 
147 void mmc_spi_put_pdata(struct spi_device *spi)
148 {
149 	struct device *dev = &spi->dev;
150 	struct device_node *np = dev->of_node;
151 	struct of_mmc_spi *oms = to_of_mmc_spi(dev);
152 
153 	if (!dev->platform_data || !np)
154 		return;
155 
156 	kfree(oms);
157 	dev->platform_data = NULL;
158 }
159 EXPORT_SYMBOL(mmc_spi_put_pdata);
160