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>
38 #include <linux/gpio.h>
40 #include <asm/uaccess.h>
43 #include <mach/board.h>
44 #include <mach/board-nokia.h>
52 static int retu_initialized;
53 static int retu_irq_pin;
54 static int retu_is_vilma;
56 static struct tasklet_struct retu_tasklet;
57 spinlock_t retu_lock = SPIN_LOCK_UNLOCKED;
59 static struct completion device_release;
61 struct retu_irq_handler_desc {
62 int (*func)(unsigned long);
67 static struct retu_irq_handler_desc retu_irq_handlers[MAX_RETU_IRQ_HANDLERS];
70 * retu_read_reg - Read a value from a register in Retu
71 * @reg: the register to read from
73 * This function returns the contents of the specified register
75 int retu_read_reg(int reg)
77 BUG_ON(!retu_initialized);
78 return cbus_read_reg(cbus_host, RETU_ID, reg);
82 * retu_write_reg - Write a value to a register in Retu
83 * @reg: the register to write to
84 * @reg: the value to write to the register
86 * This function writes a value to the specified register
88 void retu_write_reg(int reg, u16 val)
90 BUG_ON(!retu_initialized);
91 cbus_write_reg(cbus_host, RETU_ID, reg, val);
94 void retu_set_clear_reg_bits(int reg, u16 set, u16 clear)
99 spin_lock_irqsave(&retu_lock, flags);
100 w = retu_read_reg(reg);
103 retu_write_reg(reg, w);
104 spin_unlock_irqrestore(&retu_lock, flags);
107 #define ADC_MAX_CHAN_NUMBER 13
109 int retu_read_adc(int channel)
114 if (channel < 0 || channel > ADC_MAX_CHAN_NUMBER)
117 spin_lock_irqsave(&retu_lock, flags);
119 if ((channel == 8) && retu_is_vilma) {
120 int scr = retu_read_reg(RETU_REG_ADCSCR);
121 int ch = (retu_read_reg(RETU_REG_ADCR) >> 10) & 0xf;
122 if (((scr & 0xff) != 0) && (ch != 8))
123 retu_write_reg (RETU_REG_ADCSCR, (scr & ~0xff));
126 /* Select the channel and read result */
127 retu_write_reg(RETU_REG_ADCR, channel << 10);
128 res = retu_read_reg(RETU_REG_ADCR) & 0x3ff;
131 retu_write_reg(RETU_REG_ADCR, (1 << 13));
134 spin_unlock_irqrestore(&retu_lock, flags);
140 static u16 retu_disable_bogus_irqs(u16 mask)
144 for (i = 0; i < MAX_RETU_IRQ_HANDLERS; i++) {
147 if (retu_irq_handlers[i].func != NULL)
149 /* an IRQ was enabled but we don't have a handler for it */
150 printk(KERN_INFO PFX "disabling bogus IRQ %d\n", i);
157 * Disable given RETU interrupt
159 void retu_disable_irq(int id)
164 spin_lock_irqsave(&retu_lock, flags);
165 mask = retu_read_reg(RETU_REG_IMR);
167 mask = retu_disable_bogus_irqs(mask);
168 retu_write_reg(RETU_REG_IMR, mask);
169 spin_unlock_irqrestore(&retu_lock, flags);
173 * Enable given RETU interrupt
175 void retu_enable_irq(int id)
181 printk("Enabling Retu IRQ %d\n", id);
184 spin_lock_irqsave(&retu_lock, flags);
185 mask = retu_read_reg(RETU_REG_IMR);
187 mask = retu_disable_bogus_irqs(mask);
188 retu_write_reg(RETU_REG_IMR, mask);
189 spin_unlock_irqrestore(&retu_lock, flags);
193 * Acknowledge given RETU interrupt
195 void retu_ack_irq(int id)
197 retu_write_reg(RETU_REG_IDR, 1 << id);
201 * RETU interrupt handler. Only schedules the tasklet.
203 static irqreturn_t retu_irq_handler(int irq, void *dev_id)
205 tasklet_schedule(&retu_tasklet);
212 static void retu_tasklet_handler(unsigned long data)
214 struct retu_irq_handler_desc *hnd;
220 id = retu_read_reg(RETU_REG_IDR);
221 im = ~retu_read_reg(RETU_REG_IMR);
227 for (i = 0; id != 0; i++, id >>= 1) {
230 hnd = &retu_irq_handlers[i];
231 if (hnd->func == NULL) {
232 /* Spurious retu interrupt - disable and ack it */
233 printk(KERN_INFO "Spurious Retu interrupt "
241 * Don't acknowledge the interrupt here
242 * It must be done explicitly
249 * Register the handler for a given RETU interrupt source.
251 int retu_request_irq(int id, void *irq_handler, unsigned long arg, char *name)
253 struct retu_irq_handler_desc *hnd;
255 if (irq_handler == NULL || id >= MAX_RETU_IRQ_HANDLERS ||
257 printk(KERN_ERR PFX "Invalid arguments to %s\n",
261 hnd = &retu_irq_handlers[id];
262 if (hnd->func != NULL) {
263 printk(KERN_ERR PFX "IRQ %d already reserved\n", id);
266 printk(KERN_INFO PFX "Registering interrupt %d for device %s\n",
268 hnd->func = irq_handler;
270 strlcpy(hnd->name, name, sizeof(hnd->name));
279 * Unregister the handler for a given RETU interrupt source.
281 void retu_free_irq(int id)
283 struct retu_irq_handler_desc *hnd;
285 if (id >= MAX_RETU_IRQ_HANDLERS) {
286 printk(KERN_ERR PFX "Invalid argument to %s\n",
290 hnd = &retu_irq_handlers[id];
291 if (hnd->func == NULL) {
292 printk(KERN_ERR PFX "IRQ %d already freed\n", id);
296 retu_disable_irq(id);
301 * retu_power_off - Shut down power to system
303 * This function puts the system in power off state
305 static void retu_power_off(void)
307 /* Ignore power button state */
308 retu_write_reg(RETU_REG_CC1, retu_read_reg(RETU_REG_CC1) | 2);
309 /* Expire watchdog immediately */
310 retu_write_reg(RETU_REG_WATCHDOG, 0);
311 /* Wait for poweroff*/
316 * retu_probe - Probe for Retu ASIC
317 * @dev: the Retu device
319 * Probe for the Retu ASIC and allocate memory
320 * for its device-struct if found
322 static int __devinit retu_probe(struct device *dev)
324 const struct omap_em_asic_bb5_config * em_asic_config;
327 /* Prepare tasklet */
328 tasklet_init(&retu_tasklet, retu_tasklet_handler, 0);
330 em_asic_config = omap_get_config(OMAP_TAG_EM_ASIC_BB5,
331 struct omap_em_asic_bb5_config);
332 if (em_asic_config == NULL) {
333 printk(KERN_ERR PFX "Unable to retrieve config data\n");
337 retu_irq_pin = em_asic_config->retu_irq_gpio;
339 if ((ret = gpio_request(retu_irq_pin, "RETU irq")) < 0) {
340 printk(KERN_ERR PFX "Unable to reserve IRQ GPIO\n");
344 /* Set the pin as input */
345 gpio_direction_input(retu_irq_pin);
347 /* Rising edge triggers the IRQ */
348 set_irq_type(gpio_to_irq(retu_irq_pin), IRQ_TYPE_EDGE_RISING);
350 retu_initialized = 1;
352 rev = retu_read_reg(RETU_REG_ASICR) & 0xff;
356 printk(KERN_INFO "%s v%d.%d found\n", retu_is_vilma ? "Vilma" : "Retu",
357 (rev >> 4) & 0x07, rev & 0x0f);
359 /* Mask all RETU interrupts */
360 retu_write_reg(RETU_REG_IMR, 0xffff);
362 ret = request_irq(gpio_to_irq(retu_irq_pin), retu_irq_handler, 0,
365 printk(KERN_ERR PFX "Unable to register IRQ handler\n");
366 gpio_free(retu_irq_pin);
369 set_irq_wake(gpio_to_irq(retu_irq_pin), 1);
371 /* Register power off function */
372 pm_power_off = retu_power_off;
374 #ifdef CONFIG_CBUS_RETU_USER
375 /* Initialize user-space interface */
376 if (retu_user_init() < 0) {
377 printk(KERN_ERR "Unable to initialize driver\n");
378 free_irq(gpio_to_irq(retu_irq_pin), 0);
379 gpio_free(retu_irq_pin);
387 static int retu_remove(struct device *dev)
389 #ifdef CONFIG_CBUS_RETU_USER
392 /* Mask all RETU interrupts */
393 retu_write_reg(RETU_REG_IMR, 0xffff);
394 free_irq(gpio_to_irq(retu_irq_pin), 0);
395 gpio_free(retu_irq_pin);
396 tasklet_kill(&retu_tasklet);
401 static void retu_device_release(struct device *dev)
403 complete(&device_release);
406 static struct device_driver retu_driver = {
408 .bus = &platform_bus_type,
410 .remove = retu_remove,
413 static struct platform_device retu_device = {
417 .release = retu_device_release,
422 * retu_init - initialise Retu driver
424 * Initialise the Retu driver and return 0 if everything worked ok
426 static int __init retu_init(void)
430 printk(KERN_INFO "Retu/Vilma driver initialising\n");
432 init_completion(&device_release);
434 if ((ret = driver_register(&retu_driver)) < 0)
437 if ((ret = platform_device_register(&retu_device)) < 0) {
438 driver_unregister(&retu_driver);
447 static void __exit retu_exit(void)
449 platform_device_unregister(&retu_device);
450 driver_unregister(&retu_driver);
451 wait_for_completion(&device_release);
454 EXPORT_SYMBOL(retu_request_irq);
455 EXPORT_SYMBOL(retu_free_irq);
456 EXPORT_SYMBOL(retu_enable_irq);
457 EXPORT_SYMBOL(retu_disable_irq);
458 EXPORT_SYMBOL(retu_ack_irq);
459 EXPORT_SYMBOL(retu_read_reg);
460 EXPORT_SYMBOL(retu_write_reg);
462 subsys_initcall(retu_init);
463 module_exit(retu_exit);
465 MODULE_DESCRIPTION("Retu ASIC control");
466 MODULE_LICENSE("GPL");
467 MODULE_AUTHOR("Juha Yrjölä, David Weinehall, and Mikko Ylinen");