[PATCH 2/2] i2c: Add devtree-aware iic support for PPC4xx
Stefan Roese
sr at denx.de
Mon Oct 15 23:29:11 EST 2007
This patch reworks existing ibm-iic driver to support of_platform_device
and enables it to talk to device tree directly. The "old" OCP interface
for arch/ppc is still supported via #ifdef's and shall be removed when
arch/ppc is gone in a few months.
This is done to enable I2C support for the PPC4xx platforms now
being moved from arch/ppc (ocp) to arch/powerpc (of).
Signed-off-by: Stefan Roese <sr at denx.de>
---
drivers/i2c/busses/Kconfig | 2 +-
drivers/i2c/busses/i2c-ibm_iic.c | 209 +++++++++++++++++++++++++++++++++++++-
drivers/i2c/busses/i2c-ibm_iic.h | 2 +
3 files changed, 211 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index de95c75..a47b5e6 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -241,7 +241,7 @@ config I2C_PIIX4
config I2C_IBM_IIC
tristate "IBM PPC 4xx on-chip I2C interface"
- depends on IBM_OCP
+ depends on 4xx
help
Say Y here if you want to use IIC peripheral found on
embedded IBM PPC 4xx based systems.
diff --git a/drivers/i2c/busses/i2c-ibm_iic.c b/drivers/i2c/busses/i2c-ibm_iic.c
index 956b947..78c6bf4 100644
--- a/drivers/i2c/busses/i2c-ibm_iic.c
+++ b/drivers/i2c/busses/i2c-ibm_iic.c
@@ -39,8 +39,13 @@
#include <asm/io.h>
#include <linux/i2c.h>
#include <linux/i2c-id.h>
+
+#ifdef CONFIG_PPC_MERGE
+#include <linux/of_platform.h>
+#else
#include <asm/ocp.h>
#include <asm/ibm4xx.h>
+#endif
#include "i2c-ibm_iic.h"
@@ -57,6 +62,10 @@ static int iic_force_fast;
module_param(iic_force_fast, bool, 0);
MODULE_PARM_DESC(iic_fast_poll, "Force fast mode (400 kHz)");
+#ifdef CONFIG_PPC_MERGE
+static int device_idx = -1;
+#endif
+
#define DBG_LEVEL 0
#ifdef DBG
@@ -660,8 +669,205 @@ static inline u8 iic_clckdiv(unsigned int opb)
/*
* Register single IIC interface
*/
-static int __devinit iic_probe(struct ocp_device *ocp){
+#ifdef CONFIG_PPC_MERGE
+/*
+ * device-tree (of) when used from arch/powerpc
+ */
+static int __devinit iic_probe(struct of_device *ofdev,
+ const struct of_device_id *match)
+{
+ struct ibm_iic_private* dev;
+ struct i2c_adapter* adap;
+ struct device_node *np;
+ int ret = -ENODEV;
+ int irq, len;
+ const u32 *prop;
+ struct resource res;
+
+ np = ofdev->node;
+ if (!(dev = kzalloc(sizeof(*dev), GFP_KERNEL))) {
+ printk(KERN_CRIT "ibm-iic(%s): failed to allocate device data\n",
+ np->full_name);
+ return -ENOMEM;
+ }
+
+ dev_set_drvdata(&ofdev->dev, dev);
+
+ dev->np = np;
+ irq = irq_of_parse_and_map(np, 0);
+
+ if (of_address_to_resource(np, 0, &res)) {
+ printk(KERN_ERR "ibd-iic(%s): Can't get registers address\n",
+ np->full_name);
+ goto fail1;
+ }
+ dev->paddr = res.start;
+
+ if (!request_mem_region(dev->paddr, sizeof(struct iic_regs), "ibm_iic")) {
+ ret = -EBUSY;
+ goto fail1;
+ }
+ dev->vaddr = ioremap(dev->paddr, sizeof(struct iic_regs));
+
+ if (dev->vaddr == NULL) {
+ printk(KERN_CRIT "ibm-iic(%s): failed to ioremap device regs\n",
+ dev->np->full_name);
+ ret = -ENXIO;
+ goto fail2;
+ }
+
+ init_waitqueue_head(&dev->wq);
+
+ dev->irq = iic_force_poll ? -1 : (irq == NO_IRQ) ? -1 : irq;
+ if (dev->irq >= 0){
+ /* Disable interrupts until we finish initialization,
+ * assumes level-sensitive IRQ setup...
+ */
+ iic_interrupt_mode(dev, 0);
+ if (request_irq(dev->irq, iic_handler, 0, "IBM IIC", dev)) {
+ printk(KERN_ERR "ibm-iic(%s): request_irq %d failed\n",
+ dev->np->full_name, dev->irq);
+ /* Fallback to the polling mode */
+ dev->irq = -1;
+ }
+ }
+
+ if (dev->irq < 0)
+ printk(KERN_WARNING "ibm-iic(%s): using polling mode\n",
+ dev->np->full_name);
+
+ /* Board specific settings */
+ prop = of_get_property(np, "iic-mode", &len);
+ /* use 400kHz only if stated in dts, 100kHz otherwise */
+ dev->fast_mode = (prop && (*prop == 400));
+ /* clckdiv is the same for *all* IIC interfaces,
+ * but I'd rather make a copy than introduce another global. --ebs
+ */
+ /* Parent bus should have frequency filled */
+ prop = of_get_property(of_get_parent(np), "clock-frequency", &len);
+ if (prop == NULL) {
+ printk(KERN_ERR
+ "ibm-iic(%s):no clock-frequency prop on parent bus!\n",
+ dev->np->full_name);
+ goto fail;
+ }
+
+ dev->clckdiv = iic_clckdiv(*prop);
+ DBG("%s: clckdiv = %d\n", dev->np->full_name, dev->clckdiv);
+
+ /* Initialize IIC interface */
+ iic_dev_init(dev);
+
+ /* Register it with i2c layer */
+ adap = &dev->adap;
+ adap->dev.parent = &ofdev->dev;
+ strcpy(adap->name, "IBM IIC");
+ i2c_set_adapdata(adap, dev);
+ adap->id = I2C_HW_OCP;
+ adap->class = I2C_CLASS_HWMON;
+ adap->algo = &iic_algo;
+ adap->client_register = NULL;
+ adap->client_unregister = NULL;
+ adap->timeout = 1;
+ adap->retries = 1;
+
+ dev->idx = ++device_idx;
+ adap->nr = dev->idx;
+ if ((ret = i2c_add_numbered_adapter(adap)) < 0) {
+ printk(KERN_CRIT"ibm-iic(%s): failed to register i2c adapter\n",
+ dev->np->full_name);
+ goto fail;
+ }
+
+ printk(KERN_INFO "ibm-iic(%s): using %s mode\n", dev->np->full_name,
+ dev->fast_mode ?
+ "fast (400 kHz)" : "standard (100 kHz)");
+
+ return 0;
+
+fail:
+ if (dev->irq >= 0){
+ iic_interrupt_mode(dev, 0);
+ free_irq(dev->irq, dev);
+ }
+
+ iounmap(dev->vaddr);
+fail2:
+ release_mem_region(dev->paddr, sizeof(struct iic_regs));
+fail1:
+ dev_set_drvdata(&ofdev->dev, NULL);
+ kfree(dev);
+
+ return ret;
+}
+
+/*
+ * Cleanup initialized IIC interface
+ */
+static int __devexit iic_remove(struct of_device *ofdev)
+{
+ struct ibm_iic_private *dev =
+ (struct ibm_iic_private *)dev_get_drvdata(&ofdev->dev);
+ BUG_ON(dev == NULL);
+ if (i2c_del_adapter(&dev->adap)){
+ printk(KERN_CRIT "ibm-iic(%s): failed to delete i2c adapter\n",
+ dev->np->full_name);
+ /* That's *very* bad, just shutdown IRQ ... */
+ if (dev->irq >= 0){
+ iic_interrupt_mode(dev, 0);
+ free_irq(dev->irq, dev);
+ dev->irq = -1;
+ }
+ } else {
+ if (dev->irq >= 0){
+ iic_interrupt_mode(dev, 0);
+ free_irq(dev->irq, dev);
+ }
+ iounmap(dev->vaddr);
+ release_mem_region(dev->paddr, sizeof(struct iic_regs));
+ kfree(dev);
+ }
+ return 0;
+}
+
+static struct of_device_id ibm_iic_match[] = {
+ {
+ .type = "i2c",
+ .compatible = "ibm,iic",
+ },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, ibm_iic_match);
+
+static struct of_platform_driver ibm_iic_driver = {
+ .name = "ibm-iic",
+ .match_table = ibm_iic_match,
+ .probe = iic_probe,
+ .remove = iic_remove,
+#if defined(CONFIG_PM)
+ .suspend = NULL,
+ .resume = NULL,
+#endif
+};
+
+static int __init iic_init(void)
+{
+ printk(KERN_INFO "IBM IIC driver v" DRIVER_VERSION "\n");
+ return of_register_platform_driver(&ibm_iic_driver);
+}
+
+static void __exit iic_exit(void)
+{
+ of_unregister_platform_driver(&ibm_iic_driver);
+}
+#else
+/*
+ * OCP when used from arch/ppc
+ */
+static int __devinit iic_probe(struct ocp_device *ocp)
+{
struct ibm_iic_private* dev;
struct i2c_adapter* adap;
struct ocp_func_iic_data* iic_data = ocp->def->additions;
@@ -828,6 +1034,7 @@ static void __exit iic_exit(void)
{
ocp_unregister_driver(&ibm_iic_driver);
}
+#endif /* CONFIG_PPC_MERGE */
module_init(iic_init);
module_exit(iic_exit);
diff --git a/drivers/i2c/busses/i2c-ibm_iic.h b/drivers/i2c/busses/i2c-ibm_iic.h
index fdaa482..c15b091 100644
--- a/drivers/i2c/busses/i2c-ibm_iic.h
+++ b/drivers/i2c/busses/i2c-ibm_iic.h
@@ -50,6 +50,8 @@ struct ibm_iic_private {
int irq;
int fast_mode;
u8 clckdiv;
+ struct device_node *np;
+ phys_addr_t paddr;
};
/* IICx_CNTL register */
--
1.5.3.4
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