MFD: ucb1x00: convert to use genirq

Convert the ucb1x00 driver to use genirq's interrupt services, rather
than its own private implementation.  This allows a wider range of
drivers to use the GPIO interrupts (such as the gpio_keys driver)
without being aware of the UCB1x00's private IRQ system.

This prevents the UCB1x00 core driver from being built as a module,
so adjust the configuration to add that restriction.

Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 128 insertions, 161 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index cd13e9f2f5e6..28a301b28579 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -847,8 +847,9 @@ config MCP_SA11X0
 
 # Chip drivers
 config MCP_UCB1200
-        tristate "Support for UCB1200 / UCB1300"
-        depends on MCP
+        bool "Support for UCB1200 / UCB1300"
+        depends on MCP_SA11X0
+        select MCP
 
 config MCP_UCB1200_TS
         tristate "Touchscreen interface support"
diff --git a/drivers/mfd/ucb1x00-core.c b/drivers/mfd/ucb1x00-core.c
index 6fab82557543..400604d38780 100644
--- a/drivers/mfd/ucb1x00-core.c
+++ b/drivers/mfd/ucb1x00-core.c
@@ -23,6 +23,7 @@
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/device.h>
 #include <linux/mutex.h>
 #include <linux/mfd/ucb1x00.h>
@@ -178,6 +179,13 @@ static int ucb1x00_gpio_direction_output(struct gpio_chip *chip, unsigned offset
         return 0;
 }
 
+static int ucb1x00_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+        struct ucb1x00 *ucb = container_of(chip, struct ucb1x00, gpio);
+
+        return ucb->irq_base > 0 ? ucb->irq_base + offset : -ENXIO;
+}
+
 /*
  * UCB1300 data sheet says we must:
  *  1. enable ADC       => 5us (including reference startup time)
@@ -274,10 +282,9 @@ void ucb1x00_adc_disable(struct ucb1x00 *ucb)
  * SIBCLK to talk to the chip.  We leave the clock running until
  * we have finished processing all interrupts from the chip.
  */
-static irqreturn_t ucb1x00_irq(int irqnr, void *devid)
+static void ucb1x00_irq(unsigned int irq, struct irq_desc *desc)
 {
-        struct ucb1x00 *ucb = devid;
-        struct ucb1x00_irq *irq;
+        struct ucb1x00 *ucb = irq_desc_get_handler_data(desc);
         unsigned int isr, i;
 
         ucb1x00_enable(ucb);
@@ -285,157 +292,84 @@ static irqreturn_t ucb1x00_irq(int irqnr, void *devid)
         ucb1x00_reg_write(ucb, UCB_IE_CLEAR, isr);
         ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);
 
-        for (i = 0, irq = ucb->irq_handler; i < 16 && isr; i++, isr >>= 1, irq++)
-                if (isr & 1 && irq->fn)
-                        irq->fn(i, irq->devid);
+        for (i = 0; i < 16 && isr; i++, isr >>= 1, irq++)
+                if (isr & 1)
+                        generic_handle_irq(ucb->irq_base + i);
         ucb1x00_disable(ucb);
-
-        return IRQ_HANDLED;
 }
 
-/**
- *      ucb1x00_hook_irq - hook a UCB1x00 interrupt
- *      @ucb:   UCB1x00 structure describing chip
- *      @idx:   interrupt index
- *      @fn:    function to call when interrupt is triggered
- *      @devid: device id to pass to interrupt handler
- *
- *      Hook the specified interrupt.  You can only register one handler
- *      for each interrupt source.  The interrupt source is not enabled
- *      by this function; use ucb1x00_enable_irq instead.
- *
- *      Interrupt handlers will be called with other interrupts enabled.
- *
- *      Returns zero on success, or one of the following errors:
- *       -EINVAL if the interrupt index is invalid
- *       -EBUSY if the interrupt has already been hooked
- */
-int ucb1x00_hook_irq(struct ucb1x00 *ucb, unsigned int idx, void (*fn)(int, void *), void *devid)
+static void ucb1x00_irq_update(struct ucb1x00 *ucb, unsigned mask)
 {
-        struct ucb1x00_irq *irq;
-        int ret = -EINVAL;
-
-        if (idx < 16) {
-                irq = ucb->irq_handler + idx;
-                ret = -EBUSY;
-
-                spin_lock_irq(&ucb->lock);
-                if (irq->fn == NULL) {
-                        irq->devid = devid;
-                        irq->fn = fn;
-                        ret = 0;
-                }
-                spin_unlock_irq(&ucb->lock);
-        }
-        return ret;
+        ucb1x00_enable(ucb);
+        if (ucb->irq_ris_enbl & mask)
+                ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
+                                  ucb->irq_mask);
+        if (ucb->irq_fal_enbl & mask)
+                ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
+                                  ucb->irq_mask);
+        ucb1x00_disable(ucb);
 }
 
-/**
- *      ucb1x00_enable_irq - enable an UCB1x00 interrupt source
- *      @ucb: UCB1x00 structure describing chip
- *      @idx: interrupt index
- *      @edges: interrupt edges to enable
- *
- *      Enable the specified interrupt to trigger on %UCB_RISING,
- *      %UCB_FALLING or both edges.  The interrupt should have been
- *      hooked by ucb1x00_hook_irq.
- */
-void ucb1x00_enable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges)
+static void ucb1x00_irq_noop(struct irq_data *data)
 {
-        unsigned long flags;
-
-        if (idx < 16) {
-                spin_lock_irqsave(&ucb->lock, flags);
-
-                ucb1x00_enable(ucb);
-                if (edges & UCB_RISING) {
-                        ucb->irq_ris_enbl |= 1 << idx;
-                        ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
-                }
-                if (edges & UCB_FALLING) {
-                        ucb->irq_fal_enbl |= 1 << idx;
-                        ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
-                }
-                ucb1x00_disable(ucb);
-                spin_unlock_irqrestore(&ucb->lock, flags);
-        }
 }
 
-/**
- *      ucb1x00_disable_irq - disable an UCB1x00 interrupt source
- *      @ucb: UCB1x00 structure describing chip
- *      @edges: interrupt edges to disable
- *
- *      Disable the specified interrupt triggering on the specified
- *      (%UCB_RISING, %UCB_FALLING or both) edges.
- */
-void ucb1x00_disable_irq(struct ucb1x00 *ucb, unsigned int idx, int edges)
+static void ucb1x00_irq_mask(struct irq_data *data)
 {
-        unsigned long flags;
+        struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
+        unsigned mask = 1 << (data->irq - ucb->irq_base);
 
-        if (idx < 16) {
-                spin_lock_irqsave(&ucb->lock, flags);
-
-                ucb1x00_enable(ucb);
-                if (edges & UCB_RISING) {
-                        ucb->irq_ris_enbl &= ~(1 << idx);
-                        ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
-                }
-                if (edges & UCB_FALLING) {
-                        ucb->irq_fal_enbl &= ~(1 << idx);
-                        ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
-                }
-                ucb1x00_disable(ucb);
-                spin_unlock_irqrestore(&ucb->lock, flags);
-        }
+        raw_spin_lock(&ucb->irq_lock);
+        ucb->irq_mask &= ~mask;
+        ucb1x00_irq_update(ucb, mask);
+        raw_spin_unlock(&ucb->irq_lock);
 }
 
-/**
- *      ucb1x00_free_irq - disable and free the specified UCB1x00 interrupt
- *      @ucb: UCB1x00 structure describing chip
- *      @idx: interrupt index
- *      @devid: device id.
- *
- *      Disable the interrupt source and remove the handler.  devid must
- *      match the devid passed when hooking the interrupt.
- *
- *      Returns zero on success, or one of the following errors:
- *       -EINVAL if the interrupt index is invalid
- *       -ENOENT if devid does not match
- */
-int ucb1x00_free_irq(struct ucb1x00 *ucb, unsigned int idx, void *devid)
+static void ucb1x00_irq_unmask(struct irq_data *data)
 {
-        struct ucb1x00_irq *irq;
-        int ret;
+        struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
+        unsigned mask = 1 << (data->irq - ucb->irq_base);
 
-        if (idx >= 16)
-                goto bad;
-
-        irq = ucb->irq_handler + idx;
-        ret = -ENOENT;
+        raw_spin_lock(&ucb->irq_lock);
+        ucb->irq_mask |= mask;
+        ucb1x00_irq_update(ucb, mask);
+        raw_spin_unlock(&ucb->irq_lock);
+}
 
-        spin_lock_irq(&ucb->lock);
-        if (irq->devid == devid) {
-                ucb->irq_ris_enbl &= ~(1 << idx);
-                ucb->irq_fal_enbl &= ~(1 << idx);
+static int ucb1x00_irq_set_type(struct irq_data *data, unsigned int type)
+{
+        struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
+        unsigned mask = 1 << (data->irq - ucb->irq_base);
 
-                ucb1x00_enable(ucb);
-                ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl);
-                ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl);
-                ucb1x00_disable(ucb);
+        raw_spin_lock(&ucb->irq_lock);
+        if (type & IRQ_TYPE_EDGE_RISING)
+                ucb->irq_ris_enbl |= mask;
+        else
+                ucb->irq_ris_enbl &= ~mask;
 
-                irq->fn = NULL;
-                irq->devid = NULL;
-                ret = 0;
+        if (type & IRQ_TYPE_EDGE_FALLING)
+                ucb->irq_fal_enbl |= mask;
+        else
+                ucb->irq_fal_enbl &= ~mask;
+        if (ucb->irq_mask & mask) {
+                ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
+                                  ucb->irq_mask);
+                ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
+                                  ucb->irq_mask);
         }
-        spin_unlock_irq(&ucb->lock);
-        return ret;
+        raw_spin_unlock(&ucb->irq_lock);
 
-bad:
-        printk(KERN_ERR "Freeing bad UCB1x00 irq %d\n", idx);
-        return -EINVAL;
+        return 0;
 }
 
+static struct irq_chip ucb1x00_irqchip = {
+        .name = "ucb1x00",
+        .irq_ack = ucb1x00_irq_noop,
+        .irq_mask = ucb1x00_irq_mask,
+        .irq_unmask = ucb1x00_irq_unmask,
+        .irq_set_type = ucb1x00_irq_set_type,
+};
+
 static int ucb1x00_add_dev(struct ucb1x00 *ucb, struct ucb1x00_driver *drv)
 {
         struct ucb1x00_dev *dev;
@@ -545,9 +479,8 @@ static int ucb1x00_probe(struct mcp *mcp)
         struct ucb1x00_plat_data *pdata = mcp->attached_device.platform_data;
         struct ucb1x00_driver *drv;
         struct ucb1x00 *ucb;
-        unsigned int id;
+        unsigned id, i, irq_base;
         int ret = -ENODEV;
-        int temp;
 
         /* Tell the platform to deassert the UCB1x00 reset */
         if (pdata && pdata->reset)
@@ -572,7 +505,7 @@ static int ucb1x00_probe(struct mcp *mcp)
         ucb->dev.parent = &mcp->attached_device;
         dev_set_name(&ucb->dev, "ucb1x00");
 
-        spin_lock_init(&ucb->lock);
+        raw_spin_lock_init(&ucb->irq_lock);
         spin_lock_init(&ucb->io_lock);
         mutex_init(&ucb->adc_mutex);
 
@@ -593,6 +526,26 @@ static int ucb1x00_probe(struct mcp *mcp)
         }
 
         ucb->gpio.base = -1;
+        irq_base = pdata ? pdata->irq_base : 0;
+        ucb->irq_base = irq_alloc_descs(-1, irq_base, 16, -1);
+        if (ucb->irq_base < 0) {
+                dev_err(&ucb->dev, "unable to allocate 16 irqs: %d\n",
+                        ucb->irq_base);
+                goto err_irq_alloc;
+        }
+
+        for (i = 0; i < 16; i++) {
+                unsigned irq = ucb->irq_base + i;
+
+                irq_set_chip_and_handler(irq, &ucb1x00_irqchip, handle_edge_irq);
+                irq_set_chip_data(irq, ucb);
+                set_irq_flags(irq, IRQF_VALID | IRQ_NOREQUEST);
+        }
+
+        irq_set_irq_type(ucb->irq, IRQ_TYPE_EDGE_RISING);
+        irq_set_handler_data(ucb->irq, ucb);
+        irq_set_chained_handler(ucb->irq, ucb1x00_irq);
+
         if (pdata && pdata->gpio_base) {
                 ucb->gpio.label = dev_name(&ucb->dev);
                 ucb->gpio.dev = &ucb->dev;
@@ -603,20 +556,13 @@ static int ucb1x00_probe(struct mcp *mcp)
                 ucb->gpio.get = ucb1x00_gpio_get;
                 ucb->gpio.direction_input = ucb1x00_gpio_direction_input;
                 ucb->gpio.direction_output = ucb1x00_gpio_direction_output;
+                ucb->gpio.to_irq = ucb1x00_to_irq;
                 ret = gpiochip_add(&ucb->gpio);
                 if (ret)
                         goto err_gpio_add;
         } else
                 dev_info(&ucb->dev, "gpio_base not set so no gpiolib support");
 
-        ret = request_irq(ucb->irq, ucb1x00_irq, IRQF_TRIGGER_RISING,
-                          "UCB1x00", ucb);
-        if (ret) {
-                dev_err(&ucb->dev, "ucb1x00: unable to grab irq%d: %d\n",
-                        ucb->irq, ret);
-                goto err_irq;
-        }
-
         mcp_set_drvdata(mcp, ucb);
 
         INIT_LIST_HEAD(&ucb->devs);
@@ -629,10 +575,11 @@ static int ucb1x00_probe(struct mcp *mcp)
 
         return ret;
 
- err_irq:
-        if (ucb->gpio.base != -1)
-                temp = gpiochip_remove(&ucb->gpio);
  err_gpio_add:
+        irq_set_chained_handler(ucb->irq, NULL);
+ err_irq_alloc:
+        if (ucb->irq_base > 0)
+                irq_free_descs(ucb->irq_base, 16);
  err_no_irq:
         device_del(&ucb->dev);
  err_dev_add:
@@ -664,7 +611,8 @@ static void ucb1x00_remove(struct mcp *mcp)
                         dev_err(&ucb->dev, "Can't remove gpio chip: %d\n", ret);
         }
 
-        free_irq(ucb->irq, ucb);
+        irq_set_chained_handler(ucb->irq, NULL);
+        irq_free_descs(ucb->irq_base, 16);
         device_unregister(&ucb->dev);
 
         if (pdata && pdata->reset)
@@ -772,11 +720,6 @@ EXPORT_SYMBOL(ucb1x00_adc_enable);
 EXPORT_SYMBOL(ucb1x00_adc_read);
 EXPORT_SYMBOL(ucb1x00_adc_disable);
 
-EXPORT_SYMBOL(ucb1x00_hook_irq);
-EXPORT_SYMBOL(ucb1x00_free_irq);
-EXPORT_SYMBOL(ucb1x00_enable_irq);
-EXPORT_SYMBOL(ucb1x00_disable_irq);
-
 EXPORT_SYMBOL(ucb1x00_register_driver);
 EXPORT_SYMBOL(ucb1x00_unregister_driver);
 
diff --git a/drivers/mfd/ucb1x00-ts.c b/drivers/mfd/ucb1x00-ts.c
index 742d0c7bbbc2..1e0e20c0e082 100644
--- a/drivers/mfd/ucb1x00-ts.c
+++ b/drivers/mfd/ucb1x00-ts.c
@@ -20,8 +20,9 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/init.h>
-#include <linux/smp.h>
+#include <linux/interrupt.h>
 #include <linux/sched.h>
+#include <linux/spinlock.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/string.h>
@@ -41,6 +42,8 @@ struct ucb1x00_ts {
         struct input_dev        *idev;
         struct ucb1x00          *ucb;
 
+        spinlock_t              irq_lock;
+        unsigned                irq_disabled;
         wait_queue_head_t       irq_wait;
         struct task_struct      *rtask;
         u16                     x_res;
@@ -237,7 +240,12 @@ static int ucb1x00_thread(void *_ts)
                 if (ucb1x00_ts_pen_down(ts)) {
                         set_current_state(TASK_INTERRUPTIBLE);
 
-                        ucb1x00_enable_irq(ts->ucb, UCB_IRQ_TSPX, machine_is_collie() ? UCB_RISING : UCB_FALLING);
+                        spin_lock_irq(&ts->irq_lock);
+                        if (ts->irq_disabled) {
+                                ts->irq_disabled = 0;
+                                enable_irq(ts->ucb->irq_base + UCB_IRQ_TSPX);
+                        }
+                        spin_unlock_irq(&ts->irq_lock);
                         ucb1x00_disable(ts->ucb);
 
                         /*
@@ -280,23 +288,37 @@ static int ucb1x00_thread(void *_ts)
  * We only detect touch screen _touches_ with this interrupt
  * handler, and even then we just schedule our task.
  */
-static void ucb1x00_ts_irq(int idx, void *id)
+static irqreturn_t ucb1x00_ts_irq(int irq, void *id)
 {
         struct ucb1x00_ts *ts = id;
 
-        ucb1x00_disable_irq(ts->ucb, UCB_IRQ_TSPX, UCB_FALLING);
+        spin_lock(&ts->irq_lock);
+        ts->irq_disabled = 1;
+        disable_irq_nosync(ts->ucb->irq_base + UCB_IRQ_TSPX);
+        spin_unlock(&ts->irq_lock);
         wake_up(&ts->irq_wait);
+
+        return IRQ_HANDLED;
 }
 
 static int ucb1x00_ts_open(struct input_dev *idev)
 {
         struct ucb1x00_ts *ts = input_get_drvdata(idev);
+        unsigned long flags = 0;
         int ret = 0;
 
         BUG_ON(ts->rtask);
 
+        if (machine_is_collie())
+                flags = IRQF_TRIGGER_RISING;
+        else
+                flags = IRQF_TRIGGER_FALLING;
+
+        ts->irq_disabled = 0;
+
         init_waitqueue_head(&ts->irq_wait);
-        ret = ucb1x00_hook_irq(ts->ucb, UCB_IRQ_TSPX, ucb1x00_ts_irq, ts);
+        ret = request_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ucb1x00_ts_irq,
+                          flags, "ucb1x00-ts", ts);
         if (ret < 0)
                 goto out;
 
@@ -313,7 +335,7 @@ static int ucb1x00_ts_open(struct input_dev *idev)
         if (!IS_ERR(ts->rtask)) {
                 ret = 0;
         } else {
-                ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+                free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
                 ts->rtask = NULL;
                 ret = -EFAULT;
         }
@@ -333,7 +355,7 @@ static void ucb1x00_ts_close(struct input_dev *idev)
                 kthread_stop(ts->rtask);
 
         ucb1x00_enable(ts->ucb);
-        ucb1x00_free_irq(ts->ucb, UCB_IRQ_TSPX, ts);
+        free_irq(ts->ucb->irq_base + UCB_IRQ_TSPX, ts);
         ucb1x00_reg_write(ts->ucb, UCB_TS_CR, 0);
         ucb1x00_disable(ts->ucb);
 }
@@ -358,6 +380,7 @@ static int ucb1x00_ts_add(struct ucb1x00_dev *dev)
         ts->ucb = dev->ucb;
         ts->idev = idev;
         ts->adcsync = adcsync ? UCB_SYNC : UCB_NOSYNC;
+        spin_lock_init(&ts->irq_lock);
 
         idev->name       = "Touchscreen panel";
         idev->id.product = ts->ucb->id;