1/*
2 * Memory-mapped interface driver for DW SPI Core
3 *
4 * Copyright (c) 2010, Octasic semiconductor.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 */
10
11#include <linux/clk.h>
12#include <linux/err.h>
13#include <linux/interrupt.h>
14#include <linux/platform_device.h>
15#include <linux/slab.h>
16#include <linux/spi/spi.h>
17#include <linux/scatterlist.h>
18#include <linux/module.h>
19#include <linux/of.h>
20#include <linux/of_gpio.h>
21#include <linux/of_platform.h>
22
23#include "spi-dw.h"
24
25#define DRIVER_NAME "dw_spi_mmio"
26
27struct dw_spi_mmio {
28	struct dw_spi  dws;
29	struct clk     *clk;
30};
31
32static int dw_spi_mmio_probe(struct platform_device *pdev)
33{
34	struct dw_spi_mmio *dwsmmio;
35	struct dw_spi *dws;
36	struct resource *mem;
37	int ret;
38	int num_cs;
39
40	dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
41			GFP_KERNEL);
42	if (!dwsmmio)
43		return -ENOMEM;
44
45	dws = &dwsmmio->dws;
46
47	/* Get basic io resource and map it */
48	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
49	if (!mem) {
50		dev_err(&pdev->dev, "no mem resource?\n");
51		return -EINVAL;
52	}
53
54	dws->regs = devm_ioremap_resource(&pdev->dev, mem);
55	if (IS_ERR(dws->regs)) {
56		dev_err(&pdev->dev, "SPI region map failed\n");
57		return PTR_ERR(dws->regs);
58	}
59
60	dws->irq = platform_get_irq(pdev, 0);
61	if (dws->irq < 0) {
62		dev_err(&pdev->dev, "no irq resource?\n");
63		return dws->irq; /* -ENXIO */
64	}
65
66	dwsmmio->clk = devm_clk_get(&pdev->dev, NULL);
67	if (IS_ERR(dwsmmio->clk))
68		return PTR_ERR(dwsmmio->clk);
69	ret = clk_prepare_enable(dwsmmio->clk);
70	if (ret)
71		return ret;
72
73	dws->bus_num = pdev->id;
74
75	dws->max_freq = clk_get_rate(dwsmmio->clk);
76
77	of_property_read_u32(pdev->dev.of_node, "reg-io-width",
78			     &dws->reg_io_width);
79
80	num_cs = 4;
81
82	if (pdev->dev.of_node)
83		of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs);
84
85	dws->num_cs = num_cs;
86
87	if (pdev->dev.of_node) {
88		int i;
89
90		for (i = 0; i < dws->num_cs; i++) {
91			int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
92					"cs-gpios", i);
93
94			if (cs_gpio == -EPROBE_DEFER) {
95				ret = cs_gpio;
96				goto out;
97			}
98
99			if (gpio_is_valid(cs_gpio)) {
100				ret = devm_gpio_request(&pdev->dev, cs_gpio,
101						dev_name(&pdev->dev));
102				if (ret)
103					goto out;
104			}
105		}
106	}
107
108	ret = dw_spi_add_host(&pdev->dev, dws);
109	if (ret)
110		goto out;
111
112	platform_set_drvdata(pdev, dwsmmio);
113	return 0;
114
115out:
116	clk_disable_unprepare(dwsmmio->clk);
117	return ret;
118}
119
120static int dw_spi_mmio_remove(struct platform_device *pdev)
121{
122	struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
123
124	clk_disable_unprepare(dwsmmio->clk);
125	dw_spi_remove_host(&dwsmmio->dws);
126
127	return 0;
128}
129
130static const struct of_device_id dw_spi_mmio_of_match[] = {
131	{ .compatible = "snps,dw-apb-ssi", },
132	{ /* end of table */}
133};
134MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
135
136static struct platform_driver dw_spi_mmio_driver = {
137	.probe		= dw_spi_mmio_probe,
138	.remove		= dw_spi_mmio_remove,
139	.driver		= {
140		.name	= DRIVER_NAME,
141		.of_match_table = dw_spi_mmio_of_match,
142	},
143};
144module_platform_driver(dw_spi_mmio_driver);
145
146MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
147MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
148MODULE_LICENSE("GPL v2");
149