1/*
2 *  Miscellaneous functions for IDT EB434 board
3 *
4 *  Copyright 2004 IDT Inc. (rischelp@idt.com)
5 *  Copyright 2006 Phil Sutter <n0-1@freewrt.org>
6 *  Copyright 2007 Florian Fainelli <florian@openwrt.org>
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 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
14 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
15 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
16 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
17 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
19 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
21 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 *
24 *  You should have received a copy of the  GNU General Public License along
25 *  with this program; if not, write  to the Free Software Foundation, Inc.,
26 *  675 Mass Ave, Cambridge, MA 02139, USA.
27 */
28
29#include <linux/kernel.h>
30#include <linux/init.h>
31#include <linux/types.h>
32#include <linux/export.h>
33#include <linux/spinlock.h>
34#include <linux/platform_device.h>
35#include <linux/gpio.h>
36
37#include <asm/mach-rc32434/rb.h>
38#include <asm/mach-rc32434/gpio.h>
39
40struct rb532_gpio_chip {
41	struct gpio_chip chip;
42	void __iomem	 *regbase;
43};
44
45static struct resource rb532_gpio_reg0_res[] = {
46	{
47		.name	= "gpio_reg0",
48		.start	= REGBASE + GPIOBASE,
49		.end	= REGBASE + GPIOBASE + sizeof(struct rb532_gpio_reg) - 1,
50		.flags	= IORESOURCE_MEM,
51	}
52};
53
54/* rb532_set_bit - sanely set a bit
55 *
56 * bitval: new value for the bit
57 * offset: bit index in the 4 byte address range
58 * ioaddr: 4 byte aligned address being altered
59 */
60static inline void rb532_set_bit(unsigned bitval,
61		unsigned offset, void __iomem *ioaddr)
62{
63	unsigned long flags;
64	u32 val;
65
66	local_irq_save(flags);
67
68	val = readl(ioaddr);
69	val &= ~(!bitval << offset);   /* unset bit if bitval == 0 */
70	val |= (!!bitval << offset);   /* set bit if bitval == 1 */
71	writel(val, ioaddr);
72
73	local_irq_restore(flags);
74}
75
76/* rb532_get_bit - read a bit
77 *
78 * returns the boolean state of the bit, which may be > 1
79 */
80static inline int rb532_get_bit(unsigned offset, void __iomem *ioaddr)
81{
82	return readl(ioaddr) & (1 << offset);
83}
84
85/*
86 * Return GPIO level */
87static int rb532_gpio_get(struct gpio_chip *chip, unsigned offset)
88{
89	struct rb532_gpio_chip	*gpch;
90
91	gpch = container_of(chip, struct rb532_gpio_chip, chip);
92	return rb532_get_bit(offset, gpch->regbase + GPIOD);
93}
94
95/*
96 * Set output GPIO level
97 */
98static void rb532_gpio_set(struct gpio_chip *chip,
99				unsigned offset, int value)
100{
101	struct rb532_gpio_chip	*gpch;
102
103	gpch = container_of(chip, struct rb532_gpio_chip, chip);
104	rb532_set_bit(value, offset, gpch->regbase + GPIOD);
105}
106
107/*
108 * Set GPIO direction to input
109 */
110static int rb532_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
111{
112	struct rb532_gpio_chip	*gpch;
113
114	gpch = container_of(chip, struct rb532_gpio_chip, chip);
115
116	/* disable alternate function in case it's set */
117	rb532_set_bit(0, offset, gpch->regbase + GPIOFUNC);
118
119	rb532_set_bit(0, offset, gpch->regbase + GPIOCFG);
120	return 0;
121}
122
123/*
124 * Set GPIO direction to output
125 */
126static int rb532_gpio_direction_output(struct gpio_chip *chip,
127					unsigned offset, int value)
128{
129	struct rb532_gpio_chip	*gpch;
130
131	gpch = container_of(chip, struct rb532_gpio_chip, chip);
132
133	/* disable alternate function in case it's set */
134	rb532_set_bit(0, offset, gpch->regbase + GPIOFUNC);
135
136	/* set the initial output value */
137	rb532_set_bit(value, offset, gpch->regbase + GPIOD);
138
139	rb532_set_bit(1, offset, gpch->regbase + GPIOCFG);
140	return 0;
141}
142
143static int rb532_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
144{
145	return 8 + 4 * 32 + gpio;
146}
147
148static struct rb532_gpio_chip rb532_gpio_chip[] = {
149	[0] = {
150		.chip = {
151			.label			= "gpio0",
152			.direction_input	= rb532_gpio_direction_input,
153			.direction_output	= rb532_gpio_direction_output,
154			.get			= rb532_gpio_get,
155			.set			= rb532_gpio_set,
156			.to_irq			= rb532_gpio_to_irq,
157			.base			= 0,
158			.ngpio			= 32,
159		},
160	},
161};
162
163/*
164 * Set GPIO interrupt level
165 */
166void rb532_gpio_set_ilevel(int bit, unsigned gpio)
167{
168	rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOILEVEL);
169}
170EXPORT_SYMBOL(rb532_gpio_set_ilevel);
171
172/*
173 * Set GPIO interrupt status
174 */
175void rb532_gpio_set_istat(int bit, unsigned gpio)
176{
177	rb532_set_bit(bit, gpio, rb532_gpio_chip->regbase + GPIOISTAT);
178}
179EXPORT_SYMBOL(rb532_gpio_set_istat);
180
181/*
182 * Configure GPIO alternate function
183 */
184void rb532_gpio_set_func(unsigned gpio)
185{
186       rb532_set_bit(1, gpio, rb532_gpio_chip->regbase + GPIOFUNC);
187}
188EXPORT_SYMBOL(rb532_gpio_set_func);
189
190int __init rb532_gpio_init(void)
191{
192	struct resource *r;
193
194	r = rb532_gpio_reg0_res;
195	rb532_gpio_chip->regbase = ioremap_nocache(r->start, resource_size(r));
196
197	if (!rb532_gpio_chip->regbase) {
198		printk(KERN_ERR "rb532: cannot remap GPIO register 0\n");
199		return -ENXIO;
200	}
201
202	/* Register our GPIO chip */
203	gpiochip_add(&rb532_gpio_chip->chip);
204
205	return 0;
206}
207arch_initcall(rb532_gpio_init);
208