4 * Support functions for Retu ASIC
6 * Copyright (C) 2004, 2005 Nokia Corporation
8 * Written by Juha Yrjölä <juha.yrjola@nokia.com>,
9 * David Weinehall <david.weinehall@nokia.com>, and
10 * Mikko Ylinen <mikko.k.ylinen@nokia.com>
12 * This file is subject to the terms and conditions of the GNU General
13 * Public License. See the file "COPYING" in the main directory of this
14 * archive for more details.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 #include <linux/module.h>
27 #include <linux/init.h>
29 #include <linux/kernel.h>
30 #include <linux/errno.h>
31 #include <linux/device.h>
32 #include <linux/miscdevice.h>
33 #include <linux/poll.h>
35 #include <linux/irq.h>
36 #include <linux/interrupt.h>
37 #include <linux/platform_device.h>
39 #include <asm/uaccess.h>
41 #include <asm/arch/mux.h>
42 #include <asm/arch/gpio.h>
43 #include <asm/arch/board.h>
51 static int retu_initialized;
52 static int retu_irq_pin;
53 static int retu_is_vilma;
55 static struct tasklet_struct retu_tasklet;
56 spinlock_t retu_lock = SPIN_LOCK_UNLOCKED;
58 static struct completion device_release;
60 struct retu_irq_handler_desc {
61 int (*func)(unsigned long);
66 static struct retu_irq_handler_desc retu_irq_handlers[MAX_RETU_IRQ_HANDLERS];
69 * retu_read_reg - Read a value from a register in Retu
70 * @reg: the register to read from
72 * This function returns the contents of the specified register
74 int retu_read_reg(int reg)
76 BUG_ON(!retu_initialized);
77 return cbus_read_reg(cbus_host, RETU_ID, reg);
81 * retu_write_reg - Write a value to a register in Retu
82 * @reg: the register to write to
83 * @reg: the value to write to the register
85 * This function writes a value to the specified register
87 void retu_write_reg(int reg, u16 val)
89 BUG_ON(!retu_initialized);
90 cbus_write_reg(cbus_host, RETU_ID, reg, val);
93 void retu_set_clear_reg_bits(int reg, u16 set, u16 clear)
98 spin_lock_irqsave(&retu_lock, flags);
99 w = retu_read_reg(reg);
102 retu_write_reg(reg, w);
103 spin_unlock_irqrestore(&retu_lock, flags);
106 #define ADC_MAX_CHAN_NUMBER 13
108 int retu_read_adc(int channel)
113 if (channel < 0 || channel > ADC_MAX_CHAN_NUMBER)
116 spin_lock_irqsave(&retu_lock, flags);
117 /* Select the channel and read result */
118 retu_write_reg(RETU_REG_ADCR, channel << 10);
119 res = retu_read_reg(RETU_REG_ADCR) & 0x3ff;
121 spin_unlock_irqrestore(&retu_lock, flags);
127 static u16 retu_disable_bogus_irqs(u16 mask)
131 for (i = 0; i < MAX_RETU_IRQ_HANDLERS; i++) {
134 if (retu_irq_handlers[i].func != NULL)
136 /* an IRQ was enabled but we don't have a handler for it */
137 printk(KERN_INFO PFX "disabling bogus IRQ %d\n", i);
144 * Disable given RETU interrupt
146 void retu_disable_irq(int id)
151 spin_lock_irqsave(&retu_lock, flags);
152 mask = retu_read_reg(RETU_REG_IMR);
154 mask = retu_disable_bogus_irqs(mask);
155 retu_write_reg(RETU_REG_IMR, mask);
156 spin_unlock_irqrestore(&retu_lock, flags);
160 * Enable given RETU interrupt
162 void retu_enable_irq(int id)
168 printk("Enabling Retu IRQ %d\n", id);
171 spin_lock_irqsave(&retu_lock, flags);
172 mask = retu_read_reg(RETU_REG_IMR);
174 mask = retu_disable_bogus_irqs(mask);
175 retu_write_reg(RETU_REG_IMR, mask);
176 spin_unlock_irqrestore(&retu_lock, flags);
180 * Acknowledge given RETU interrupt
182 void retu_ack_irq(int id)
184 retu_write_reg(RETU_REG_IDR, 1 << id);
188 * RETU interrupt handler. Only schedules the tasklet.
190 static irqreturn_t retu_irq_handler(int irq, void *dev_id)
192 tasklet_schedule(&retu_tasklet);
199 static void retu_tasklet_handler(unsigned long data)
201 struct retu_irq_handler_desc *hnd;
207 id = retu_read_reg(RETU_REG_IDR);
208 im = ~retu_read_reg(RETU_REG_IMR);
214 for (i = 0; id != 0; i++, id >>= 1) {
217 hnd = &retu_irq_handlers[i];
218 if (hnd->func == NULL) {
219 /* Spurious retu interrupt - disable and ack it */
220 printk(KERN_INFO "Spurious Retu interrupt "
228 * Don't acknowledge the interrupt here
229 * It must be done explicitly
236 * Register the handler for a given RETU interrupt source.
238 int retu_request_irq(int id, void *irq_handler, unsigned long arg, char *name)
240 struct retu_irq_handler_desc *hnd;
242 if (irq_handler == NULL || id >= MAX_RETU_IRQ_HANDLERS ||
244 printk(KERN_ERR PFX "Invalid arguments to %s\n",
248 hnd = &retu_irq_handlers[id];
249 if (hnd->func != NULL) {
250 printk(KERN_ERR PFX "IRQ %d already reserved\n", id);
253 printk(KERN_INFO PFX "Registering interrupt %d for device %s\n",
255 hnd->func = irq_handler;
257 strlcpy(hnd->name, name, sizeof(hnd->name));
266 * Unregister the handler for a given RETU interrupt source.
268 void retu_free_irq(int id)
270 struct retu_irq_handler_desc *hnd;
272 if (id >= MAX_RETU_IRQ_HANDLERS) {
273 printk(KERN_ERR PFX "Invalid argument to %s\n",
277 hnd = &retu_irq_handlers[id];
278 if (hnd->func == NULL) {
279 printk(KERN_ERR PFX "IRQ %d already freed\n", id);
283 retu_disable_irq(id);
288 * retu_power_off - Shut down power to system
290 * This function puts the system in power off state
292 static void retu_power_off(void)
294 /* Ignore power button state */
295 retu_write_reg(RETU_REG_CC1, retu_read_reg(RETU_REG_CC1) | 2);
296 /* Expire watchdog immediately */
297 retu_write_reg(RETU_REG_WATCHDOG, 0);
298 /* Wait for poweroff*/
303 * retu_probe - Probe for Retu ASIC
304 * @dev: the Retu device
306 * Probe for the Retu ASIC and allocate memory
307 * for its device-struct if found
309 static int __devinit retu_probe(struct device *dev)
311 const struct omap_em_asic_bb5_config * em_asic_config;
314 /* Prepare tasklet */
315 tasklet_init(&retu_tasklet, retu_tasklet_handler, 0);
317 em_asic_config = omap_get_config(OMAP_TAG_EM_ASIC_BB5,
318 struct omap_em_asic_bb5_config);
319 if (em_asic_config == NULL) {
320 printk(KERN_ERR PFX "Unable to retrieve config data\n");
324 retu_irq_pin = em_asic_config->retu_irq_gpio;
326 if ((ret = omap_request_gpio(retu_irq_pin)) < 0) {
327 printk(KERN_ERR PFX "Unable to reserve IRQ GPIO\n");
331 /* Set the pin as input */
332 omap_set_gpio_direction(retu_irq_pin, 1);
334 /* Rising edge triggers the IRQ */
335 set_irq_type(OMAP_GPIO_IRQ(retu_irq_pin), IRQT_RISING);
337 retu_initialized = 1;
339 rev = retu_read_reg(RETU_REG_ASICR) & 0xff;
343 printk(KERN_INFO "%s v%d.%d found\n", retu_is_vilma ? "Vilma" : "Retu",
344 (rev >> 4) & 0x07, rev & 0x0f);
346 /* Mask all RETU interrupts */
347 retu_write_reg(RETU_REG_IMR, 0xffff);
349 ret = request_irq(OMAP_GPIO_IRQ(retu_irq_pin), retu_irq_handler, 0,
352 printk(KERN_ERR PFX "Unable to register IRQ handler\n");
353 omap_free_gpio(retu_irq_pin);
356 set_irq_wake(OMAP_GPIO_IRQ(retu_irq_pin), 1);
358 /* Register power off function */
359 pm_power_off = retu_power_off;
361 #ifdef CONFIG_CBUS_RETU_USER
362 /* Initialize user-space interface */
363 if (retu_user_init() < 0) {
364 printk(KERN_ERR "Unable to initialize driver\n");
365 free_irq(OMAP_GPIO_IRQ(retu_irq_pin), 0);
366 omap_free_gpio(retu_irq_pin);
374 static int retu_remove(struct device *dev)
376 #ifdef CONFIG_CBUS_RETU_USER
379 /* Mask all RETU interrupts */
380 retu_write_reg(RETU_REG_IMR, 0xffff);
381 free_irq(OMAP_GPIO_IRQ(retu_irq_pin), 0);
382 omap_free_gpio(retu_irq_pin);
383 tasklet_kill(&retu_tasklet);
388 static void retu_device_release(struct device *dev)
390 complete(&device_release);
393 static struct device_driver retu_driver = {
395 .bus = &platform_bus_type,
397 .remove = retu_remove,
400 static struct platform_device retu_device = {
404 .release = retu_device_release,
409 * retu_init - initialise Retu driver
411 * Initialise the Retu driver and return 0 if everything worked ok
413 static int __init retu_init(void)
417 printk(KERN_INFO "Retu/Vilma driver initialising\n");
419 init_completion(&device_release);
421 if ((ret = driver_register(&retu_driver)) < 0)
424 if ((ret = platform_device_register(&retu_device)) < 0) {
425 driver_unregister(&retu_driver);
434 static void __exit retu_exit(void)
436 platform_device_unregister(&retu_device);
437 driver_unregister(&retu_driver);
438 wait_for_completion(&device_release);
441 EXPORT_SYMBOL(retu_request_irq);
442 EXPORT_SYMBOL(retu_free_irq);
443 EXPORT_SYMBOL(retu_enable_irq);
444 EXPORT_SYMBOL(retu_disable_irq);
445 EXPORT_SYMBOL(retu_ack_irq);
446 EXPORT_SYMBOL(retu_read_reg);
447 EXPORT_SYMBOL(retu_write_reg);
449 subsys_initcall(retu_init);
450 module_exit(retu_exit);
452 MODULE_DESCRIPTION("Retu ASIC control");
453 MODULE_LICENSE("GPL");
454 MODULE_AUTHOR("Juha Yrjölä, David Weinehall, and Mikko Ylinen");