xref: /openbmc/linux/drivers/mmc/host/of_mmc_spi.c (revision b4e18b29)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OpenFirmware bindings for the MMC-over-SPI driver
4  *
5  * Copyright (c) MontaVista Software, Inc. 2008.
6  *
7  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/device.h>
13 #include <linux/slab.h>
14 #include <linux/irq.h>
15 #include <linux/of.h>
16 #include <linux/of_irq.h>
17 #include <linux/spi/spi.h>
18 #include <linux/spi/mmc_spi.h>
19 #include <linux/mmc/core.h>
20 #include <linux/mmc/host.h>
21 
22 /* For archs that don't support NO_IRQ (such as mips), provide a dummy value */
23 #ifndef NO_IRQ
24 #define NO_IRQ 0
25 #endif
26 
27 MODULE_LICENSE("GPL");
28 
29 struct of_mmc_spi {
30 	int detect_irq;
31 	struct mmc_spi_platform_data pdata;
32 };
33 
34 static struct of_mmc_spi *to_of_mmc_spi(struct device *dev)
35 {
36 	return container_of(dev->platform_data, struct of_mmc_spi, pdata);
37 }
38 
39 static int of_mmc_spi_init(struct device *dev,
40 			   irqreturn_t (*irqhandler)(int, void *), void *mmc)
41 {
42 	struct of_mmc_spi *oms = to_of_mmc_spi(dev);
43 
44 	return request_threaded_irq(oms->detect_irq, NULL, irqhandler,
45 					IRQF_ONESHOT, dev_name(dev), mmc);
46 }
47 
48 static void of_mmc_spi_exit(struct device *dev, void *mmc)
49 {
50 	struct of_mmc_spi *oms = to_of_mmc_spi(dev);
51 
52 	free_irq(oms->detect_irq, mmc);
53 }
54 
55 struct mmc_spi_platform_data *mmc_spi_get_pdata(struct spi_device *spi)
56 {
57 	struct device *dev = &spi->dev;
58 	struct device_node *np = dev->of_node;
59 	struct of_mmc_spi *oms;
60 
61 	if (dev->platform_data || !np)
62 		return dev->platform_data;
63 
64 	oms = kzalloc(sizeof(*oms), GFP_KERNEL);
65 	if (!oms)
66 		return NULL;
67 
68 	if (mmc_of_parse_voltage(np, &oms->pdata.ocr_mask) <= 0)
69 		goto err_ocr;
70 
71 	oms->detect_irq = irq_of_parse_and_map(np, 0);
72 	if (oms->detect_irq != 0) {
73 		oms->pdata.init = of_mmc_spi_init;
74 		oms->pdata.exit = of_mmc_spi_exit;
75 	} else {
76 		oms->pdata.caps |= MMC_CAP_NEEDS_POLL;
77 	}
78 
79 	dev->platform_data = &oms->pdata;
80 	return dev->platform_data;
81 err_ocr:
82 	kfree(oms);
83 	return NULL;
84 }
85 EXPORT_SYMBOL(mmc_spi_get_pdata);
86 
87 void mmc_spi_put_pdata(struct spi_device *spi)
88 {
89 	struct device *dev = &spi->dev;
90 	struct device_node *np = dev->of_node;
91 	struct of_mmc_spi *oms = to_of_mmc_spi(dev);
92 
93 	if (!dev->platform_data || !np)
94 		return;
95 
96 	kfree(oms);
97 	dev->platform_data = NULL;
98 }
99 EXPORT_SYMBOL(mmc_spi_put_pdata);
100