--- /dev/null
+/**
+ * drivers/cbus/retu.c
+ *
+ * Support functions for Retu ASIC
+ *
+ * Copyright (C) 2004, 2005 Nokia Corporation
+ *
+ * Written by Juha Yrjölä <juha.yrjola@nokia.com>,
+ * David Weinehall <david.weinehall@nokia.com>, and
+ * Mikko Ylinen <mikko.k.ylinen@nokia.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/poll.h>
+#include <linux/fs.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+
+#include <asm/uaccess.h>
+
+#include <mach/mux.h>
+#include <mach/board.h>
+#include <mach/board-nokia.h>
+
+#include "cbus.h"
+#include "retu.h"
+
+#define RETU_ID 0x01
+#define PFX "retu: "
+
+static int retu_initialized;
+static int retu_irq_pin;
+static int retu_is_vilma;
+
+static struct tasklet_struct retu_tasklet;
+spinlock_t retu_lock = SPIN_LOCK_UNLOCKED;
+
+static struct completion device_release;
+
+struct retu_irq_handler_desc {
+ int (*func)(unsigned long);
+ unsigned long arg;
+ char name[8];
+};
+
+static struct retu_irq_handler_desc retu_irq_handlers[MAX_RETU_IRQ_HANDLERS];
+
+/**
+ * retu_read_reg - Read a value from a register in Retu
+ * @reg: the register to read from
+ *
+ * This function returns the contents of the specified register
+ */
+int retu_read_reg(int reg)
+{
+ BUG_ON(!retu_initialized);
+ return cbus_read_reg(cbus_host, RETU_ID, reg);
+}
+
+/**
+ * retu_write_reg - Write a value to a register in Retu
+ * @reg: the register to write to
+ * @reg: the value to write to the register
+ *
+ * This function writes a value to the specified register
+ */
+void retu_write_reg(int reg, u16 val)
+{
+ BUG_ON(!retu_initialized);
+ cbus_write_reg(cbus_host, RETU_ID, reg, val);
+}
+
+void retu_set_clear_reg_bits(int reg, u16 set, u16 clear)
+{
+ unsigned long flags;
+ u16 w;
+
+ spin_lock_irqsave(&retu_lock, flags);
+ w = retu_read_reg(reg);
+ w &= ~clear;
+ w |= set;
+ retu_write_reg(reg, w);
+ spin_unlock_irqrestore(&retu_lock, flags);
+}
+
+#define ADC_MAX_CHAN_NUMBER 13
+
+int retu_read_adc(int channel)
+{
+ unsigned long flags;
+ int res;
+
+ if (channel < 0 || channel > ADC_MAX_CHAN_NUMBER)
+ return -EINVAL;
+
+ spin_lock_irqsave(&retu_lock, flags);
+
+ if ((channel == 8) && retu_is_vilma) {
+ int scr = retu_read_reg(RETU_REG_ADCSCR);
+ int ch = (retu_read_reg(RETU_REG_ADCR) >> 10) & 0xf;
+ if (((scr & 0xff) != 0) && (ch != 8))
+ retu_write_reg (RETU_REG_ADCSCR, (scr & ~0xff));
+ }
+
+ /* Select the channel and read result */
+ retu_write_reg(RETU_REG_ADCR, channel << 10);
+ res = retu_read_reg(RETU_REG_ADCR) & 0x3ff;
+
+ if (retu_is_vilma)
+ retu_write_reg(RETU_REG_ADCR, (1 << 13));
+
+ /* Unlock retu */
+ spin_unlock_irqrestore(&retu_lock, flags);
+
+ return res;
+}
+
+
+static u16 retu_disable_bogus_irqs(u16 mask)
+{
+ int i;
+
+ for (i = 0; i < MAX_RETU_IRQ_HANDLERS; i++) {
+ if (mask & (1 << i))
+ continue;
+ if (retu_irq_handlers[i].func != NULL)
+ continue;
+ /* an IRQ was enabled but we don't have a handler for it */
+ printk(KERN_INFO PFX "disabling bogus IRQ %d\n", i);
+ mask |= (1 << i);
+ }
+ return mask;
+}
+
+/*
+ * Disable given RETU interrupt
+ */
+void retu_disable_irq(int id)
+{
+ unsigned long flags;
+ u16 mask;
+
+ spin_lock_irqsave(&retu_lock, flags);
+ mask = retu_read_reg(RETU_REG_IMR);
+ mask |= 1 << id;
+ mask = retu_disable_bogus_irqs(mask);
+ retu_write_reg(RETU_REG_IMR, mask);
+ spin_unlock_irqrestore(&retu_lock, flags);
+}
+
+/*
+ * Enable given RETU interrupt
+ */
+void retu_enable_irq(int id)
+{
+ unsigned long flags;
+ u16 mask;
+
+ if (id == 3) {
+ printk("Enabling Retu IRQ %d\n", id);
+ dump_stack();
+ }
+ spin_lock_irqsave(&retu_lock, flags);
+ mask = retu_read_reg(RETU_REG_IMR);
+ mask &= ~(1 << id);
+ mask = retu_disable_bogus_irqs(mask);
+ retu_write_reg(RETU_REG_IMR, mask);
+ spin_unlock_irqrestore(&retu_lock, flags);
+}
+
+/*
+ * Acknowledge given RETU interrupt
+ */
+void retu_ack_irq(int id)
+{
+ retu_write_reg(RETU_REG_IDR, 1 << id);
+}
+
+/*
+ * RETU interrupt handler. Only schedules the tasklet.
+ */
+static irqreturn_t retu_irq_handler(int irq, void *dev_id)
+{
+ tasklet_schedule(&retu_tasklet);
+ return IRQ_HANDLED;
+}
+
+/*
+ * Tasklet handler
+ */
+static void retu_tasklet_handler(unsigned long data)
+{
+ struct retu_irq_handler_desc *hnd;
+ u16 id;
+ u16 im;
+ int i;
+
+ for (;;) {
+ id = retu_read_reg(RETU_REG_IDR);
+ im = ~retu_read_reg(RETU_REG_IMR);
+ id &= im;
+
+ if (!id)
+ break;
+
+ for (i = 0; id != 0; i++, id >>= 1) {
+ if (!(id & 1))
+ continue;
+ hnd = &retu_irq_handlers[i];
+ if (hnd->func == NULL) {
+ /* Spurious retu interrupt - disable and ack it */
+ printk(KERN_INFO "Spurious Retu interrupt "
+ "(id %d)\n", i);
+ retu_disable_irq(i);
+ retu_ack_irq(i);
+ continue;
+ }
+ hnd->func(hnd->arg);
+ /*
+ * Don't acknowledge the interrupt here
+ * It must be done explicitly
+ */
+ }
+ }
+}
+
+/*
+ * Register the handler for a given RETU interrupt source.
+ */
+int retu_request_irq(int id, void *irq_handler, unsigned long arg, char *name)
+{
+ struct retu_irq_handler_desc *hnd;
+
+ if (irq_handler == NULL || id >= MAX_RETU_IRQ_HANDLERS ||
+ name == NULL) {
+ printk(KERN_ERR PFX "Invalid arguments to %s\n",
+ __FUNCTION__);
+ return -EINVAL;
+ }
+ hnd = &retu_irq_handlers[id];
+ if (hnd->func != NULL) {
+ printk(KERN_ERR PFX "IRQ %d already reserved\n", id);
+ return -EBUSY;
+ }
+ printk(KERN_INFO PFX "Registering interrupt %d for device %s\n",
+ id, name);
+ hnd->func = irq_handler;
+ hnd->arg = arg;
+ strlcpy(hnd->name, name, sizeof(hnd->name));
+
+ retu_ack_irq(id);
+ retu_enable_irq(id);
+
+ return 0;
+}
+
+/*
+ * Unregister the handler for a given RETU interrupt source.
+ */
+void retu_free_irq(int id)
+{
+ struct retu_irq_handler_desc *hnd;
+
+ if (id >= MAX_RETU_IRQ_HANDLERS) {
+ printk(KERN_ERR PFX "Invalid argument to %s\n",
+ __FUNCTION__);
+ return;
+ }
+ hnd = &retu_irq_handlers[id];
+ if (hnd->func == NULL) {
+ printk(KERN_ERR PFX "IRQ %d already freed\n", id);
+ return;
+ }
+
+ retu_disable_irq(id);
+ hnd->func = NULL;
+}
+
+/**
+ * retu_power_off - Shut down power to system
+ *
+ * This function puts the system in power off state
+ */
+static void retu_power_off(void)
+{
+ /* Ignore power button state */
+ retu_write_reg(RETU_REG_CC1, retu_read_reg(RETU_REG_CC1) | 2);
+ /* Expire watchdog immediately */
+ retu_write_reg(RETU_REG_WATCHDOG, 0);
+ /* Wait for poweroff*/
+ for (;;);
+}
+
+/**
+ * retu_probe - Probe for Retu ASIC
+ * @dev: the Retu device
+ *
+ * Probe for the Retu ASIC and allocate memory
+ * for its device-struct if found
+ */
+static int __devinit retu_probe(struct device *dev)
+{
+ const struct omap_em_asic_bb5_config * em_asic_config;
+ int rev, ret;
+
+ /* Prepare tasklet */
+ tasklet_init(&retu_tasklet, retu_tasklet_handler, 0);
+
+ em_asic_config = omap_get_config(OMAP_TAG_EM_ASIC_BB5,
+ struct omap_em_asic_bb5_config);
+ if (em_asic_config == NULL) {
+ printk(KERN_ERR PFX "Unable to retrieve config data\n");
+ return -ENODATA;
+ }
+
+ retu_irq_pin = em_asic_config->retu_irq_gpio;
+
+ if ((ret = gpio_request(retu_irq_pin, "RETU irq")) < 0) {
+ printk(KERN_ERR PFX "Unable to reserve IRQ GPIO\n");
+ return ret;
+ }
+
+ /* Set the pin as input */
+ gpio_direction_input(retu_irq_pin);
+
+ /* Rising edge triggers the IRQ */
+ set_irq_type(gpio_to_irq(retu_irq_pin), IRQ_TYPE_EDGE_RISING);
+
+ retu_initialized = 1;
+
+ rev = retu_read_reg(RETU_REG_ASICR) & 0xff;
+ if (rev & (1 << 7))
+ retu_is_vilma = 1;
+
+ printk(KERN_INFO "%s v%d.%d found\n", retu_is_vilma ? "Vilma" : "Retu",
+ (rev >> 4) & 0x07, rev & 0x0f);
+
+ /* Mask all RETU interrupts */
+ retu_write_reg(RETU_REG_IMR, 0xffff);
+
+ ret = request_irq(gpio_to_irq(retu_irq_pin), retu_irq_handler, 0,
+ "retu", 0);
+ if (ret < 0) {
+ printk(KERN_ERR PFX "Unable to register IRQ handler\n");
+ gpio_free(retu_irq_pin);
+ return ret;
+ }
+ set_irq_wake(gpio_to_irq(retu_irq_pin), 1);
+
+ /* Register power off function */
+ pm_power_off = retu_power_off;
+
+#ifdef CONFIG_CBUS_RETU_USER
+ /* Initialize user-space interface */
+ if (retu_user_init() < 0) {
+ printk(KERN_ERR "Unable to initialize driver\n");
+ free_irq(gpio_to_irq(retu_irq_pin), 0);
+ gpio_free(retu_irq_pin);
+ return ret;
+ }
+#endif
+
+ return 0;
+}
+
+static int retu_remove(struct device *dev)
+{
+#ifdef CONFIG_CBUS_RETU_USER
+ retu_user_cleanup();
+#endif
+ /* Mask all RETU interrupts */
+ retu_write_reg(RETU_REG_IMR, 0xffff);
+ free_irq(gpio_to_irq(retu_irq_pin), 0);
+ gpio_free(retu_irq_pin);
+ tasklet_kill(&retu_tasklet);
+
+ return 0;
+}
+
+static void retu_device_release(struct device *dev)
+{
+ complete(&device_release);
+}
+
+static struct device_driver retu_driver = {
+ .name = "retu",
+ .bus = &platform_bus_type,
+ .probe = retu_probe,
+ .remove = retu_remove,
+};
+
+static struct platform_device retu_device = {
+ .name = "retu",
+ .id = -1,
+ .dev = {
+ .release = retu_device_release,
+ }
+};
+
+/**
+ * retu_init - initialise Retu driver
+ *
+ * Initialise the Retu driver and return 0 if everything worked ok
+ */
+static int __init retu_init(void)
+{
+ int ret = 0;
+
+ printk(KERN_INFO "Retu/Vilma driver initialising\n");
+
+ init_completion(&device_release);
+
+ if ((ret = driver_register(&retu_driver)) < 0)
+ return ret;
+
+ if ((ret = platform_device_register(&retu_device)) < 0) {
+ driver_unregister(&retu_driver);
+ return ret;
+ }
+ return 0;
+}
+
+/*
+ * Cleanup
+ */
+static void __exit retu_exit(void)
+{
+ platform_device_unregister(&retu_device);
+ driver_unregister(&retu_driver);
+ wait_for_completion(&device_release);
+}
+
+EXPORT_SYMBOL(retu_request_irq);
+EXPORT_SYMBOL(retu_free_irq);
+EXPORT_SYMBOL(retu_enable_irq);
+EXPORT_SYMBOL(retu_disable_irq);
+EXPORT_SYMBOL(retu_ack_irq);
+EXPORT_SYMBOL(retu_read_reg);
+EXPORT_SYMBOL(retu_write_reg);
+
+subsys_initcall(retu_init);
+module_exit(retu_exit);
+
+MODULE_DESCRIPTION("Retu ASIC control");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Juha Yrjölä, David Weinehall, and Mikko Ylinen");
projects / linux-2.6-omap-h63xx.git / blobdiff