[PATCH V2 0/3] i2c-nomadik changes

[PATCH V2 0/3] i2c-nomadik changes

[Alessandro Rubini]

V2:
	- use linux/platform_data/i2c-nomadik.h not linux/i2c-nomadik.h
	- format patch with -M
	- added lee jones to the Cc: list (for device tree support)
	- minor rewording of the commit messages

Slightly edited for typos explanation, otherwise same as V1:

The patch set turns a platform device into an amba device. Its users,
i.e. mach-ux500, are converted too.  The set has no external
dependencies, although is has no visible effect until other patches
are accepted.

Reasoning:

In the STA2X11 I/O hub we are exporting a number of AMBA peripherals
to the PCI world. By using a generic pci-amba driver there is no further
code for each device, provided they are already registered under the
AMBA bus.  I already submitted the generic bridge and I'm waiting for
feedback on it (https://lkml.org/lkml/2012/5/28/194).

Status of this patch set:

The users of the driver (i.e. mach-ux500) compile properly, but I
couldn't test on any board.  The driver, as is, works on x86 under the
PCI bridge, with the not-yet-upstream clock framework and platform
data for sta2x11 devices.  However, this set is not introducing any
dead code as it only adds more flexibility.  Most of the patch is
just two renames: s/platform_device/amba_device/ and s/pdev/adev/ .

Alessandro Rubini (3):
  i2c-nomadik: move header to <linux/platform_data/i2c-nomadik.h>
  i2c-nomadik: turn the platform driver to an amba driver
  i2c-nomadik: depend on ARM_AMBA, not PLAT_NOMADIK

 arch/arm/mach-ux500/board-mop500.c                 |    2 +-
 arch/arm/mach-ux500/devices-common.h               |   23 +---
 drivers/i2c/busses/Kconfig                         |    5 +-
 drivers/i2c/busses/i2c-nomadik.c                   |  140 ++++++++++----------
 .../linux/platform_data/i2c-nomadik.h              |    6 +-
 5 files changed, 80 insertions(+), 96 deletions(-)
 rename arch/arm/plat-nomadik/include/plat/i2c.h => include/linux/platform_data/i2c-nomadik.h (91%)

-- 
1.7.7.2

[PATCH V2 1/3] i2c-nomadik: move header to <linux/platform_data/i2c-nomadik.h>

[Alessandro Rubini]

The header and driver are only used by arm/mach-u8500 (and potentially
arm/mach-nomadik), but the STA2X11 I/O Hub exports on PCIe a number of
devices, including i2c-nomadik.  This patch allows compilation of the
driver under x86.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
---
 arch/arm/mach-ux500/board-mop500.c                 |    2 +-
 arch/arm/mach-ux500/devices-common.h               |    2 +-
 drivers/i2c/busses/i2c-nomadik.c                   |    3 +--
 .../linux/platform_data/i2c-nomadik.h              |    6 +++---
 4 files changed, 6 insertions(+), 7 deletions(-)
 rename arch/arm/plat-nomadik/include/plat/i2c.h => include/linux/platform_data/i2c-nomadik.h (91%)

diff --git a/arch/arm/mach-ux500/board-mop500.c b/arch/arm/mach-ux500/board-mop500.c
index 9c74ac5..0bf24bb 100644
--- a/arch/arm/mach-ux500/board-mop500.c
+++ b/arch/arm/mach-ux500/board-mop500.c
@@ -15,6 +15,7 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/i2c.h>
+#include <linux/platform_data/i2c-nomadik.h>
 #include <linux/gpio.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/pl022.h>
@@ -39,7 +40,6 @@
 #include <asm/mach/arch.h>
 #include <asm/hardware/gic.h>
 
-#include <plat/i2c.h>
 #include <plat/ste_dma40.h>
 #include <plat/gpio-nomadik.h>
 
diff --git a/arch/arm/mach-ux500/devices-common.h b/arch/arm/mach-ux500/devices-common.h
index 6e47065..23cf734 100644
--- a/arch/arm/mach-ux500/devices-common.h
+++ b/arch/arm/mach-ux500/devices-common.h
@@ -12,7 +12,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/sys_soc.h>
 #include <linux/amba/bus.h>
-#include <plat/i2c.h>
+#include <linux/platform_data/i2c-nomadik.h>
 #include <mach/crypto-ux500.h>
 
 struct spi_master_cntlr;
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index 5267ab9..752f1fd 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -23,8 +23,7 @@
 #include <linux/io.h>
 #include <linux/regulator/consumer.h>
 #include <linux/pm_runtime.h>
-
-#include <plat/i2c.h>
+#include <linux/platform_data/i2c-nomadik.h>
 
 #define DRIVER_NAME "nmk-i2c"
 
diff --git a/arch/arm/plat-nomadik/include/plat/i2c.h b/include/linux/platform_data/i2c-nomadik.h
similarity index 91%
rename from arch/arm/plat-nomadik/include/plat/i2c.h
rename to include/linux/platform_data/i2c-nomadik.h
index 8ba70ff..c2303c3 100644
--- a/arch/arm/plat-nomadik/include/plat/i2c.h
+++ b/include/linux/platform_data/i2c-nomadik.h
@@ -5,8 +5,8 @@
  * it under the terms of the GNU General Public License version 2, as
  * published by the Free Software Foundation.
  */
-#ifndef __PLAT_I2C_H
-#define __PLAT_I2C_H
+#ifndef __PDATA_I2C_NOMADIK_H
+#define __PDATA_I2C_NOMADIK_H
 
 enum i2c_freq_mode {
 	I2C_FREQ_MODE_STANDARD,		/* up to 100 Kb/s */
@@ -36,4 +36,4 @@ struct nmk_i2c_controller {
 	enum i2c_freq_mode	sm;
 };
 
-#endif	/* __PLAT_I2C_H */
+#endif	/* __PDATA_I2C_NOMADIK_H */
-- 
1.7.7.2

[PATCH V2 2/3] i2c-nomadik: turn the platform driver to an amba driver

[Alessandro Rubini]

The i2c-nomadik gateware is really a PrimeCell APB device. By hosting
the driver under the amba bus we can access it more easily, for
example using the generic pci-amba driver. The patch also fixes the
mach-ux500 users, so they register an amba device instead than a
platform device.

The cell-id I used in the amba table are the one for ux500 (only as far as
I know from the stn-8815 manuals) and the one for STA2X11.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
---
 arch/arm/mach-ux500/devices-common.h |   21 +-----
 drivers/i2c/busses/i2c-nomadik.c     |  137 +++++++++++++++++-----------------
 2 files changed, 71 insertions(+), 87 deletions(-)

diff --git a/arch/arm/mach-ux500/devices-common.h b/arch/arm/mach-ux500/devices-common.h
index 23cf734..cfee556 100644
--- a/arch/arm/mach-ux500/devices-common.h
+++ b/arch/arm/mach-ux500/devices-common.h
@@ -56,27 +56,12 @@ dbx500_add_uart(struct device *parent, const char *name, resource_size_t base,
 
 struct nmk_i2c_controller;
 
-static inline struct platform_device *
+static inline struct amba_device *
 dbx500_add_i2c(struct device *parent, int id, resource_size_t base, int irq,
 	       struct nmk_i2c_controller *data)
 {
-	struct resource res[] = {
-		DEFINE_RES_MEM(base, SZ_4K),
-		DEFINE_RES_IRQ(irq),
-	};
-
-	struct platform_device_info pdevinfo = {
-		.parent = parent,
-		.name = "nmk-i2c",
-		.id = id,
-		.res = res,
-		.num_res = ARRAY_SIZE(res),
-		.data = data,
-		.size_data = sizeof(*data),
-		.dma_mask = DMA_BIT_MASK(32),
-	};
-
-	return platform_device_register_full(&pdevinfo);
+	return amba_apb_device_add(parent, "nmk-i2c", base, SZ_4K, irq, 0,
+				   data, 0);
 }
 
 static inline struct amba_device *
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index 752f1fd..e9ed731 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -14,7 +14,7 @@
  */
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/platform_device.h>
+#include <linux/amba/bus.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
@@ -135,7 +135,7 @@ struct i2c_nmk_client {
 
 /**
  * struct nmk_i2c_dev - private data structure of the controller.
- * @pdev: parent platform device.
+ * @adev: parent amba device.
  * @adap: corresponding I2C adapter.
  * @irq: interrupt line for the controller.
  * @virtbase: virtual io memory area.
@@ -149,7 +149,7 @@ struct i2c_nmk_client {
  * @busy: Busy doing transfer.
  */
 struct nmk_i2c_dev {
-	struct platform_device		*pdev;
+	struct amba_device		*adev;
 	struct i2c_adapter		adap;
 	int				irq;
 	void __iomem			*virtbase;
@@ -216,7 +216,7 @@ static int flush_i2c_fifo(struct nmk_i2c_dev *dev)
 		}
 	}
 
-	dev_err(&dev->pdev->dev,
+	dev_err(&dev->adev->dev,
 		"flushing operation timed out giving up after %d attempts",
 		LOOP_ATTEMPTS);
 
@@ -363,7 +363,7 @@ static void setup_i2c_controller(struct nmk_i2c_dev *dev)
 	 * and high speed (up to 3.4 Mb/s)
 	 */
 	if (dev->cfg.sm > I2C_FREQ_MODE_FAST) {
-		dev_err(&dev->pdev->dev,
+		dev_err(&dev->adev->dev,
 			"do not support this mode defaulting to std. mode\n");
 		brcr2 = i2c_clk/(100000 * 2) & 0xffff;
 		writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR);
@@ -422,7 +422,7 @@ static int read_i2c(struct nmk_i2c_dev *dev)
 		&dev->xfer_complete, dev->adap.timeout);
 
 	if (timeout < 0) {
-		dev_err(&dev->pdev->dev,
+		dev_err(&dev->adev->dev,
 			"wait_for_completion_timeout "
 			"returned %d waiting for event\n", timeout);
 		status = timeout;
@@ -430,7 +430,7 @@ static int read_i2c(struct nmk_i2c_dev *dev)
 
 	if (timeout == 0) {
 		/* Controller timed out */
-		dev_err(&dev->pdev->dev, "read from slave 0x%x timed out\n",
+		dev_err(&dev->adev->dev, "read from slave 0x%x timed out\n",
 				dev->cli.slave_adr);
 		status = -ETIMEDOUT;
 	}
@@ -509,7 +509,7 @@ static int write_i2c(struct nmk_i2c_dev *dev)
 		&dev->xfer_complete, dev->adap.timeout);
 
 	if (timeout < 0) {
-		dev_err(&dev->pdev->dev,
+		dev_err(&dev->adev->dev,
 			"wait_for_completion_timeout "
 			"returned %d waiting for event\n", timeout);
 		status = timeout;
@@ -517,7 +517,7 @@ static int write_i2c(struct nmk_i2c_dev *dev)
 
 	if (timeout == 0) {
 		/* Controller timed out */
-		dev_err(&dev->pdev->dev, "write to slave 0x%x timed out\n",
+		dev_err(&dev->adev->dev, "write to slave 0x%x timed out\n",
 				dev->cli.slave_adr);
 		status = -ETIMEDOUT;
 	}
@@ -556,7 +556,7 @@ static int nmk_i2c_xfer_one(struct nmk_i2c_dev *dev, u16 flags)
 		if (((i2c_sr >> 2) & 0x3) == 0x3) {
 			/* get the abort cause */
 			cause =	(i2c_sr >> 4) & 0x7;
-			dev_err(&dev->pdev->dev, "%s\n",
+			dev_err(&dev->adev->dev, "%s\n",
 				cause >= ARRAY_SIZE(abort_causes) ?
 				"unknown reason" :
 				abort_causes[cause]);
@@ -629,7 +629,7 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
 
 	if (dev->regulator)
 		regulator_enable(dev->regulator);
-	pm_runtime_get_sync(&dev->pdev->dev);
+	pm_runtime_get_sync(&dev->adev->dev);
 
 	clk_enable(dev->clk);
 
@@ -644,7 +644,7 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
 
 		for (i = 0; i < num_msgs; i++) {
 			if (unlikely(msgs[i].flags & I2C_M_TEN)) {
-				dev_err(&dev->pdev->dev,
+				dev_err(&dev->adev->dev,
 					"10 bit addressing not supported\n");
 
 				status = -EINVAL;
@@ -666,7 +666,7 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
 
 out:
 	clk_disable(dev->clk);
-	pm_runtime_put_sync(&dev->pdev->dev);
+	pm_runtime_put_sync(&dev->adev->dev);
 	if (dev->regulator)
 		regulator_disable(dev->regulator);
 
@@ -789,7 +789,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
 
 		if (dev->cli.count) {
 			dev->result = -EIO;
-			dev_err(&dev->pdev->dev,
+			dev_err(&dev->adev->dev,
 				"%lu bytes still remain to be xfered\n",
 				dev->cli.count);
 			(void) init_hw(dev);
@@ -833,7 +833,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
 		dev->result = -EIO;
 		(void) init_hw(dev);
 
-		dev_err(&dev->pdev->dev, "Tx Fifo Over run\n");
+		dev_err(&dev->adev->dev, "Tx Fifo Over run\n");
 		complete(&dev->xfer_complete);
 
 		break;
@@ -846,10 +846,10 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
 	case I2C_IT_RFSE:
 	case I2C_IT_WTSR:
 	case I2C_IT_STD:
-		dev_err(&dev->pdev->dev, "unhandled Interrupt\n");
+		dev_err(&dev->adev->dev, "unhandled Interrupt\n");
 		break;
 	default:
-		dev_err(&dev->pdev->dev, "spurious Interrupt..\n");
+		dev_err(&dev->adev->dev, "spurious Interrupt..\n");
 		break;
 	}
 
@@ -860,8 +860,8 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
 #ifdef CONFIG_PM
 static int nmk_i2c_suspend(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct nmk_i2c_dev *nmk_i2c = platform_get_drvdata(pdev);
+	struct amba_device *adev = to_amba_device(dev);
+	struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);
 
 	if (nmk_i2c->busy)
 		return -EBUSY;
@@ -898,79 +898,67 @@ static const struct i2c_algorithm nmk_i2c_algo = {
 	.functionality	= nmk_i2c_functionality
 };
 
-static int __devinit nmk_i2c_probe(struct platform_device *pdev)
+static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
 {
 	int ret = 0;
-	struct resource *res;
 	struct nmk_i2c_controller *pdata =
-			pdev->dev.platform_data;
+			adev->dev.platform_data;
 	struct nmk_i2c_dev	*dev;
 	struct i2c_adapter *adap;
 
+	if (!pdata) {
+		dev_warn(&adev->dev, "no platform data\n");
+		return -ENODEV;
+	}
 	dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL);
 	if (!dev) {
-		dev_err(&pdev->dev, "cannot allocate memory\n");
+		dev_err(&adev->dev, "cannot allocate memory\n");
 		ret = -ENOMEM;
 		goto err_no_mem;
 	}
 	dev->busy = false;
-	dev->pdev = pdev;
-	platform_set_drvdata(pdev, dev);
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		ret = -ENOENT;
-		goto err_no_resource;
-	}
+	dev->adev = adev;
+	amba_set_drvdata(adev, dev);
 
-	if (request_mem_region(res->start, resource_size(res),
-		DRIVER_NAME "I/O region") == NULL) {
-		ret = -EBUSY;
-		goto err_no_region;
-	}
-
-	dev->virtbase = ioremap(res->start, resource_size(res));
+	dev->virtbase = ioremap(adev->res.start, resource_size(&adev->res));
 	if (!dev->virtbase) {
 		ret = -ENOMEM;
 		goto err_no_ioremap;
 	}
 
-	dev->irq = platform_get_irq(pdev, 0);
+	dev->irq = adev->irq[0];
 	ret = request_irq(dev->irq, i2c_irq_handler, 0,
 				DRIVER_NAME, dev);
 	if (ret) {
-		dev_err(&pdev->dev, "cannot claim the irq %d\n", dev->irq);
+		dev_err(&adev->dev, "cannot claim the irq %d\n", dev->irq);
 		goto err_irq;
 	}
 
-	dev->regulator = regulator_get(&pdev->dev, "v-i2c");
+	dev->regulator = regulator_get(&adev->dev, "v-i2c");
 	if (IS_ERR(dev->regulator)) {
-		dev_warn(&pdev->dev, "could not get i2c regulator\n");
+		dev_warn(&adev->dev, "could not get i2c regulator\n");
 		dev->regulator = NULL;
 	}
 
-	pm_suspend_ignore_children(&pdev->dev, true);
-	pm_runtime_enable(&pdev->dev);
+	pm_suspend_ignore_children(&adev->dev, true);
+	pm_runtime_enable(&adev->dev);
 
-	dev->clk = clk_get(&pdev->dev, NULL);
+	dev->clk = clk_get(&adev->dev, NULL);
 	if (IS_ERR(dev->clk)) {
-		dev_err(&pdev->dev, "could not get i2c clock\n");
+		dev_err(&adev->dev, "could not get i2c clock\n");
 		ret = PTR_ERR(dev->clk);
 		goto err_no_clk;
 	}
 
 	adap = &dev->adap;
-	adap->dev.parent = &pdev->dev;
+	adap->dev.parent = &adev->dev;
 	adap->owner	= THIS_MODULE;
 	adap->class	= I2C_CLASS_HWMON | I2C_CLASS_SPD;
 	adap->algo	= &nmk_i2c_algo;
 	adap->timeout	= pdata->timeout ? msecs_to_jiffies(pdata->timeout) :
 		msecs_to_jiffies(20000);
 	snprintf(adap->name, sizeof(adap->name),
-		 "Nomadik I2C%d at %lx", pdev->id, (unsigned long)res->start);
-
-	/* fetch the controller id */
-	adap->nr	= pdev->id;
+		 "Nomadik I2C%d at %pR", adap->nr, &adev->res);
 
 	/* fetch the controller configuration from machine */
 	dev->cfg.clk_freq = pdata->clk_freq;
@@ -981,13 +969,13 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
 
 	i2c_set_adapdata(adap, dev);
 
-	dev_info(&pdev->dev,
+	dev_info(&adev->dev,
 		 "initialize %s on virtual base %p\n",
 		 adap->name, dev->virtbase);
 
 	ret = i2c_add_numbered_adapter(adap);
 	if (ret) {
-		dev_err(&pdev->dev, "failed to add adapter\n");
+		dev_err(&adev->dev, "failed to add adapter\n");
 		goto err_add_adap;
 	}
 
@@ -998,25 +986,22 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
  err_no_clk:
 	if (dev->regulator)
 		regulator_put(dev->regulator);
-	pm_runtime_disable(&pdev->dev);
+	pm_runtime_disable(&adev->dev);
 	free_irq(dev->irq, dev);
  err_irq:
 	iounmap(dev->virtbase);
  err_no_ioremap:
-	release_mem_region(res->start, resource_size(res));
- err_no_region:
-	platform_set_drvdata(pdev, NULL);
- err_no_resource:
+	amba_set_drvdata(adev, NULL);
 	kfree(dev);
  err_no_mem:
 
 	return ret;
 }
 
-static int __devexit nmk_i2c_remove(struct platform_device *pdev)
+static int nmk_i2c_remove(struct amba_device *adev)
 {
-	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	struct nmk_i2c_dev *dev = platform_get_drvdata(pdev);
+	struct resource *res = &adev->res;
+	struct nmk_i2c_dev *dev = amba_get_drvdata(adev);
 
 	i2c_del_adapter(&dev->adap);
 	flush_i2c_fifo(dev);
@@ -1031,31 +1016,46 @@ static int __devexit nmk_i2c_remove(struct platform_device *pdev)
 	clk_put(dev->clk);
 	if (dev->regulator)
 		regulator_put(dev->regulator);
-	pm_runtime_disable(&pdev->dev);
-	platform_set_drvdata(pdev, NULL);
+	pm_runtime_disable(&adev->dev);
+	amba_set_drvdata(adev, NULL);
 	kfree(dev);
 
 	return 0;
 }
 
-static struct platform_driver nmk_i2c_driver = {
-	.driver = {
+static struct amba_id nmk_i2c_ids[] = {
+	{
+		.id	= 0x00018024,
+		.mask	= 0x00ffffff,
+	},
+	{
+		.id	= 0x00380024,
+		.mask	= 0x00ffffff,
+	},
+	{},
+};
+
+MODULE_DEVICE_TABLE(amba, nmk_i2c_ids);
+
+static struct amba_driver nmk_i2c_driver = {
+	.drv = {
 		.owner = THIS_MODULE,
 		.name = DRIVER_NAME,
 		.pm = &nmk_i2c_pm,
 	},
+	.id_table = nmk_i2c_ids,
 	.probe = nmk_i2c_probe,
-	.remove = __devexit_p(nmk_i2c_remove),
+	.remove = nmk_i2c_remove,
 };
 
 static int __init nmk_i2c_init(void)
 {
-	return platform_driver_register(&nmk_i2c_driver);
+	return amba_driver_register(&nmk_i2c_driver);
 }
 
 static void __exit nmk_i2c_exit(void)
 {
-	platform_driver_unregister(&nmk_i2c_driver);
+	amba_driver_unregister(&nmk_i2c_driver);
 }
 
 subsys_initcall(nmk_i2c_init);
@@ -1064,4 +1064,3 @@ module_exit(nmk_i2c_exit);
 MODULE_AUTHOR("Sachin Verma, Srinidhi KASAGAR");
 MODULE_DESCRIPTION("Nomadik/Ux500 I2C driver");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:" DRIVER_NAME);
-- 
1.7.7.2

Re: [PATCH V2 2/3] i2c-nomadik: turn the platform driver to an amba driver

[Linus Walleij]

On Thu, Jun 7, 2012 at 3:52 PM, Alessandro Rubini <rubini@gnudd.com> wrote:

> The i2c-nomadik gateware is really a PrimeCell APB device. By hosting
> the driver under the amba bus we can access it more easily, for
> example using the generic pci-amba driver. The patch also fixes the
> mach-ux500 users, so they register an amba device instead than a
> platform device.
>
> The cell-id I used in the amba table are the one for ux500 (only as far as
> I know from the stn-8815 manuals) and the one for STA2X11.
>
> Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
> Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>

OK I tested this now and it causes a fat, ugly regression on ux500 and
makes it hang at boot.

But don't worry! Because I found all the causes.

1) The devices created from dbx500_add_i2c() must have a serious name
  like "nmk-i2c.0" etc. (Caused platform to hang)

2) Each adapter needs a unique adap->nr, this patch made the driver
  into a singleton that couldn't handle multiple instances.

3) Runtime PM screams because the AMBA runtime PM semantics
  differ from the semantics of platform devices. AMBA calls probe
  with pm enabled and one get() refcound and will also disable it
  if probe fails. So just put() it at the end of probe.
  (C.f. drivers/spi/spi-pl022.c)

After fixing this it works fine on ux500. I also changed:

4) The Nomadik PrimeCell ID looks tilted 4 bits. (Haven't tested, just
  looked in the reference manual)

Suggested patch to fix the patch below, beware that gmail might
have whitespace-mangled it so you might need to edit it
manually.

diff --git a/arch/arm/mach-ux500/devices-common.h
b/arch/arm/mach-ux500/devices-common.h
index cfee556..ecdd838 100644
--- a/arch/arm/mach-ux500/devices-common.h
+++ b/arch/arm/mach-ux500/devices-common.h
@@ -60,8 +60,11 @@ static inline struct amba_device *
 dbx500_add_i2c(struct device *parent, int id, resource_size_t base, int irq,
 	       struct nmk_i2c_controller *data)
 {
-	return amba_apb_device_add(parent, "nmk-i2c", base, SZ_4K, irq, 0,
-				   data, 0);
+	/* Conjure a name similar to what the platform device used to have */
+	char name[16];
+
+	snprintf(name, sizeof(name), "nmk-i2c.%d", id);
+	return amba_apb_device_add(parent, name, base, SZ_4K, irq, 0, data, 0);
 }

 static inline struct amba_device *
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index e9ed731..6db453f 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -15,6 +15,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/amba/bus.h>
+#include <linux/atomic.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
@@ -898,6 +899,8 @@ static const struct i2c_algorithm nmk_i2c_algo = {
 	.functionality	= nmk_i2c_functionality
 };

+static atomic_t adapter_id = ATOMIC_INIT(0);
+
 static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
 {
 	int ret = 0;
@@ -941,7 +944,6 @@ static int nmk_i2c_probe(struct amba_device *adev,
const struct amba_id *id)
 	}

 	pm_suspend_ignore_children(&adev->dev, true);
-	pm_runtime_enable(&adev->dev);

 	dev->clk = clk_get(&adev->dev, NULL);
 	if (IS_ERR(dev->clk)) {
@@ -957,8 +959,10 @@ static int nmk_i2c_probe(struct amba_device
*adev, const struct amba_id *id)
 	adap->algo	= &nmk_i2c_algo;
 	adap->timeout	= pdata->timeout ? msecs_to_jiffies(pdata->timeout) :
 		msecs_to_jiffies(20000);
+	adap->nr = atomic_read(&adapter_id);
 	snprintf(adap->name, sizeof(adap->name),
 		 "Nomadik I2C%d at %pR", adap->nr, &adev->res);
+	atomic_inc(&adapter_id);

 	/* fetch the controller configuration from machine */
 	dev->cfg.clk_freq = pdata->clk_freq;
@@ -979,6 +983,8 @@ static int nmk_i2c_probe(struct amba_device *adev,
const struct amba_id *id)
 		goto err_add_adap;
 	}

+	pm_runtime_put(&adev->dev);
+
 	return 0;

  err_add_adap:
@@ -986,7 +992,6 @@ static int nmk_i2c_probe(struct amba_device *adev,
const struct amba_id *id)
  err_no_clk:
 	if (dev->regulator)
 		regulator_put(dev->regulator);
-	pm_runtime_disable(&adev->dev);
 	free_irq(dev->irq, dev);
  err_irq:
 	iounmap(dev->virtbase);
@@ -1025,7 +1030,7 @@ static int nmk_i2c_remove(struct amba_device *adev)

 static struct amba_id nmk_i2c_ids[] = {
 	{
-		.id	= 0x00018024,
+		.id	= 0x00180024,
 		.mask	= 0x00ffffff,
 	},
 	{


If you apply this and respin you can add
Tested-by: Linus Walleij <linus.walleij@linaro.org>

On all three patches.

Yours,
Linus Walleij

[PATCH V2 3/3] i2c-nomadik: depend on ARM_AMBA, not PLAT_NOMADIK

[Alessandro Rubini]

The gateware device has been used outside of the Nomadik world, using
the pci-amba bridge driver, so loosen the dependencies.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
---
 drivers/i2c/busses/Kconfig |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7244c8b..e9f9c5d 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -479,10 +479,11 @@ config I2C_MXS
 
 config I2C_NOMADIK
 	tristate "ST-Ericsson Nomadik/Ux500 I2C Controller"
-	depends on PLAT_NOMADIK
+	depends on ARM_AMBA
 	help
 	  If you say yes to this option, support will be included for the
-	  I2C interface from ST-Ericsson's Nomadik and Ux500 architectures.
+	  I2C interface from ST-Ericsson's Nomadik and Ux500 architectures,
+	  as well as the STA2X11 PCIe I/O HUB.
 
 config I2C_NUC900
 	tristate "NUC900 I2C Driver"
-- 
1.7.7.2