mfd: twl-core: Add initial DT support for twl4030/twl6030

Add initial device-tree support for twl familly chips.
The current version is missing the regulator entries due
to the lack of DT regulator bindings for the moment.
Only the simple sub-modules that do not depend on
platform_data information can be initialized properly.

Add irqdomain support.

Add documentation for the Texas Instruments TWL Integrated Chip.

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Cc: Balaji T K <balajitk@ti.com>
Cc: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
[grant.likely@secretlab.ca: Fix IRQ_DOMAIN dependency in kconfig]
Cc: Grant Likely <grant.likely@secretlab.ca>

2 files changed, 51 insertions, 2 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 0f6db32240f4..08a3e087bcea 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -200,7 +200,7 @@ config MENELAUS
 
 config TWL4030_CORE
         bool "Texas Instruments TWL4030/TWL5030/TWL6030/TPS659x0 Support"
-        depends on I2C=y && GENERIC_HARDIRQS
+        depends on I2C=y && GENERIC_HARDIRQS && IRQ_DOMAIN
         help
           Say yes here if you have TWL4030 / TWL6030 family chip on your board.
           This core driver provides register access and IRQ handling
diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index 61e70cfaa774..e04e04ddc15e 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -34,6 +34,11 @@
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/err.h>
+#include <linux/device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/irqdomain.h>
 
 #include <linux/regulator/machine.h>
 
@@ -144,6 +149,9 @@
 
 #define TWL_MODULE_LAST TWL4030_MODULE_LAST
 
+#define TWL4030_NR_IRQS    8
+#define TWL6030_NR_IRQS    20
+
 /* Base Address defns for twl4030_map[] */
 
 /* subchip/slave 0 - USB ID */
@@ -255,6 +263,7 @@ struct twl_client {
 
 static struct twl_client twl_modules[TWL_NUM_SLAVES];
 
+static struct irq_domain domain;
 
 /* mapping the module id to slave id and base address */
 struct twl_mapping {
@@ -1183,14 +1192,48 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
         int                             status;
         unsigned                        i;
         struct twl4030_platform_data    *pdata = client->dev.platform_data;
+        struct device_node              *node = client->dev.of_node;
         u8 temp;
         int ret = 0;
+        int nr_irqs = TWL4030_NR_IRQS;
+
+        if ((id->driver_data) & TWL6030_CLASS)
+                nr_irqs = TWL6030_NR_IRQS;
+
+        if (node && !pdata) {
+                /*
+                 * XXX: Temporary pdata until the information is correctly
+                 * retrieved by every TWL modules from DT.
+                 */
+                pdata = devm_kzalloc(&client->dev,
+                                     sizeof(struct twl4030_platform_data),
+                                     GFP_KERNEL);
+                if (!pdata)
+                        return -ENOMEM;
+        }
 
         if (!pdata) {
                 dev_dbg(&client->dev, "no platform data?\n");
                 return -EINVAL;
         }
 
+        status = irq_alloc_descs(-1, pdata->irq_base, nr_irqs, 0);
+        if (IS_ERR_VALUE(status)) {
+                dev_err(&client->dev, "Fail to allocate IRQ descs\n");
+                return status;
+        }
+
+        pdata->irq_base = status;
+        pdata->irq_end = pdata->irq_base + nr_irqs;
+
+        domain.irq_base = pdata->irq_base;
+        domain.nr_irq = nr_irqs;
+#ifdef CONFIG_OF_IRQ
+        domain.of_node = of_node_get(node);
+        domain.ops = &irq_domain_simple_ops;
+#endif
+        irq_domain_add(&domain);
+
         if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) == 0) {
                 dev_dbg(&client->dev, "can't talk I2C?\n");
                 return -EIO;
@@ -1270,7 +1313,13 @@ twl_probe(struct i2c_client *client, const struct i2c_device_id *id)
                 twl_i2c_write_u8(TWL4030_MODULE_INTBR, temp, REG_GPPUPDCTR1);
         }
 
-        status = add_children(pdata, id->driver_data);
+#ifdef CONFIG_OF_DEVICE
+        if (node)
+                status = of_platform_populate(node, NULL, NULL, &client->dev);
+        else
+#endif
+                status = add_children(pdata, id->driver_data);
+
 fail:
         if (status < 0)
                 twl_remove(client);