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authorAnton Vorontsov <avorontsov@ru.mvista.com>2008-09-23 10:13:00 -0400
committerKumar Gala <galak@kernel.crashing.org>2008-10-13 12:10:00 -0400
commitd6c3db83c5567b3a4d8d0bf33dc5687abdf65274 (patch)
treea9b5395bcbfd062be09c2126a59dbd5006e884f1 /drivers/i2c
parent7de0c22bba1f6117c3447af2cdca9904303012da (diff)
i2c: MPC8349E-mITX Power Management and GPIO expander driver
On MPC8349E-mITX, MPC8315E-RDB and MPC837x-RDB boards there is a Freescale MC9S08QG8 (MCU) chip with the custom firmware pre-programmed. The chip is used to power-off the board by the software, and to control some GPIO pins. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/chips/Kconfig11
-rw-r--r--drivers/i2c/chips/Makefile1
-rw-r--r--drivers/i2c/chips/mcu_mpc8349emitx.c209
3 files changed, 221 insertions, 0 deletions
diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
index a95cb9465d65..17356827b93d 100644
--- a/drivers/i2c/chips/Kconfig
+++ b/drivers/i2c/chips/Kconfig
@@ -172,4 +172,15 @@ config MENELAUS
172 and other features that are often used in portable devices like 172 and other features that are often used in portable devices like
173 cell phones and PDAs. 173 cell phones and PDAs.
174 174
175config MCU_MPC8349EMITX
176 tristate "MPC8349E-mITX MCU driver"
177 depends on I2C && PPC_83xx
178 select GENERIC_GPIO
179 select ARCH_REQUIRE_GPIOLIB
180 help
181 Say Y here to enable soft power-off functionality on the Freescale
182 boards with the MPC8349E-mITX-compatible MCU chips. This driver will
183 also register MCU GPIOs with the generic GPIO API, so you'll able
184 to use MCU pins as GPIOs.
185
175endmenu 186endmenu
diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
index 39e3e69ed125..ca520fa143d6 100644
--- a/drivers/i2c/chips/Makefile
+++ b/drivers/i2c/chips/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_ISP1301_OMAP) += isp1301_omap.o
21obj-$(CONFIG_TPS65010) += tps65010.o 21obj-$(CONFIG_TPS65010) += tps65010.o
22obj-$(CONFIG_MENELAUS) += menelaus.o 22obj-$(CONFIG_MENELAUS) += menelaus.o
23obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o 23obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o
24obj-$(CONFIG_MCU_MPC8349EMITX) += mcu_mpc8349emitx.o
24 25
25ifeq ($(CONFIG_I2C_DEBUG_CHIP),y) 26ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
26EXTRA_CFLAGS += -DDEBUG 27EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/i2c/chips/mcu_mpc8349emitx.c b/drivers/i2c/chips/mcu_mpc8349emitx.c
new file mode 100644
index 000000000000..82a9bcb858b6
--- /dev/null
+++ b/drivers/i2c/chips/mcu_mpc8349emitx.c
@@ -0,0 +1,209 @@
1/*
2 * Power Management and GPIO expander driver for MPC8349E-mITX-compatible MCU
3 *
4 * Copyright (c) 2008 MontaVista Software, Inc.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 */
13
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/device.h>
18#include <linux/mutex.h>
19#include <linux/i2c.h>
20#include <linux/gpio.h>
21#include <linux/of.h>
22#include <linux/of_gpio.h>
23#include <asm/prom.h>
24#include <asm/machdep.h>
25
26/*
27 * I don't have specifications for the MCU firmware, I found this register
28 * and bits positions by the trial&error method.
29 */
30#define MCU_REG_CTRL 0x20
31#define MCU_CTRL_POFF 0x40
32
33#define MCU_NUM_GPIO 2
34
35struct mcu {
36 struct mutex lock;
37 struct device_node *np;
38 struct i2c_client *client;
39 struct of_gpio_chip of_gc;
40 u8 reg_ctrl;
41};
42
43static struct mcu *glob_mcu;
44
45static void mcu_power_off(void)
46{
47 struct mcu *mcu = glob_mcu;
48
49 pr_info("Sending power-off request to the MCU...\n");
50 mutex_lock(&mcu->lock);
51 i2c_smbus_write_byte_data(glob_mcu->client, MCU_REG_CTRL,
52 mcu->reg_ctrl | MCU_CTRL_POFF);
53 mutex_unlock(&mcu->lock);
54}
55
56static void mcu_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
57{
58 struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
59 struct mcu *mcu = container_of(of_gc, struct mcu, of_gc);
60 u8 bit = 1 << (4 + gpio);
61
62 mutex_lock(&mcu->lock);
63 if (val)
64 mcu->reg_ctrl &= ~bit;
65 else
66 mcu->reg_ctrl |= bit;
67
68 i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL, mcu->reg_ctrl);
69 mutex_unlock(&mcu->lock);
70}
71
72static int mcu_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
73{
74 mcu_gpio_set(gc, gpio, val);
75 return 0;
76}
77
78static int mcu_gpiochip_add(struct mcu *mcu)
79{
80 struct device_node *np;
81 struct of_gpio_chip *of_gc = &mcu->of_gc;
82 struct gpio_chip *gc = &of_gc->gc;
83 int ret;
84
85 np = of_find_compatible_node(NULL, NULL, "fsl,mcu-mpc8349emitx");
86 if (!np)
87 return -ENODEV;
88
89 gc->owner = THIS_MODULE;
90 gc->label = np->full_name;
91 gc->can_sleep = 1;
92 gc->ngpio = MCU_NUM_GPIO;
93 gc->base = -1;
94 gc->set = mcu_gpio_set;
95 gc->direction_output = mcu_gpio_dir_out;
96 of_gc->gpio_cells = 2;
97 of_gc->xlate = of_gpio_simple_xlate;
98
99 np->data = of_gc;
100 mcu->np = np;
101
102 /*
103 * We don't want to lose the node, its ->data and ->full_name...
104 * So, if succeeded, we don't put the node here.
105 */
106 ret = gpiochip_add(gc);
107 if (ret)
108 of_node_put(np);
109 return ret;
110}
111
112static int mcu_gpiochip_remove(struct mcu *mcu)
113{
114 int ret;
115
116 ret = gpiochip_remove(&mcu->of_gc.gc);
117 if (ret)
118 return ret;
119 of_node_put(mcu->np);
120
121 return 0;
122}
123
124static int __devinit mcu_probe(struct i2c_client *client,
125 const struct i2c_device_id *id)
126{
127 struct mcu *mcu;
128 int ret;
129
130 mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);
131 if (!mcu)
132 return -ENOMEM;
133
134 mutex_init(&mcu->lock);
135 mcu->client = client;
136 i2c_set_clientdata(client, mcu);
137
138 ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);
139 if (ret < 0)
140 goto err;
141 mcu->reg_ctrl = ret;
142
143 ret = mcu_gpiochip_add(mcu);
144 if (ret)
145 goto err;
146
147 /* XXX: this is potentially racy, but there is no lock for ppc_md */
148 if (!ppc_md.power_off) {
149 glob_mcu = mcu;
150 ppc_md.power_off = mcu_power_off;
151 dev_info(&client->dev, "will provide power-off service\n");
152 }
153
154 return 0;
155err:
156 kfree(mcu);
157 return ret;
158}
159
160static int __devexit mcu_remove(struct i2c_client *client)
161{
162 struct mcu *mcu = i2c_get_clientdata(client);
163 int ret;
164
165 if (glob_mcu == mcu) {
166 ppc_md.power_off = NULL;
167 glob_mcu = NULL;
168 }
169
170 ret = mcu_gpiochip_remove(mcu);
171 if (ret)
172 return ret;
173 i2c_set_clientdata(client, NULL);
174 kfree(mcu);
175 return 0;
176}
177
178static const struct i2c_device_id mcu_ids[] = {
179 { "mcu-mpc8349emitx", },
180 {},
181};
182MODULE_DEVICE_TABLE(i2c, mcu_ids);
183
184static struct i2c_driver mcu_driver = {
185 .driver = {
186 .name = "mcu-mpc8349emitx",
187 .owner = THIS_MODULE,
188 },
189 .probe = mcu_probe,
190 .remove = __devexit_p(mcu_remove),
191 .id_table = mcu_ids,
192};
193
194static int __init mcu_init(void)
195{
196 return i2c_add_driver(&mcu_driver);
197}
198module_init(mcu_init);
199
200static void __exit mcu_exit(void)
201{
202 i2c_del_driver(&mcu_driver);
203}
204module_exit(mcu_exit);
205
206MODULE_DESCRIPTION("Power Management and GPIO expander driver for "
207 "MPC8349E-mITX-compatible MCU");
208MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
209MODULE_LICENSE("GPL");