[PATCH v4 0/2] i2c: i2c-ocores: Add support for sparc, custom set and get functions, and the GRLIB port of the controller

[PATCH v4 0/2] i2c: i2c-ocores: Add support for sparc, custom set and get functions, and the GRLIB port of the controller

[Andreas Larsson]

On sparc, irqs are not present as an IORESOURCE in the struct platform_device
representation. By using platform_get_irq instead of platform_get_resource the
driver works for sparc.

The GRLIB port of the ocores i2c controller needs custom getreg and setreg
functions to allow for big endian register access and to deal with the fact that
the PRELOW and PREHIGH registers have been merged into one register.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>

 Changes since v3:
 - Use a separate entry in the of match table for the grlib variant and trigger
   grlib function usage on type put in the data field of that table entry

Andreas Larsson (2):
  i2c: i2c-ocores: Add irq support for sparc
  i2c: i2c-ocores: Add support for the GRLIB port of the controller and
    custom getreg and setreg functions

 .../devicetree/bindings/i2c/i2c-ocores.txt         |    2 +-
 drivers/i2c/busses/i2c-ocores.c                    |   90 ++++++++++++++++++--
 2 files changed, 83 insertions(+), 9 deletions(-)

[PATCH v4 1/2] i2c: i2c-ocores: Add irq support for sparc

[Andreas Larsson]

Add sparc support by using platform_get_irq instead of platform_get_resource.
There are no platform resources of type IORESOURCE_IRQ for sparc, but
platform_get_irq works for sparc. In the non-sparc case platform_get_irq
internally uses platform_get_resource.

Signed-off-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Peter Korsgaard <jacmet@sunsite.dk>
---
 Changes since v3:
 - None

 drivers/i2c/busses/i2c-ocores.c |   11 ++++++-----
 1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index bffd550..1d204cb 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -267,7 +267,8 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev)
 {
 	struct ocores_i2c *i2c;
 	struct ocores_i2c_platform_data *pdata;
-	struct resource *res, *res2;
+	struct resource *res;
+	int irq;
 	int ret;
 	int i;
 
@@ -275,9 +276,9 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev)
 	if (!res)
 		return -ENODEV;
 
-	res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!res2)
-		return -ENODEV;
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
 	if (!i2c)
@@ -313,7 +314,7 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev)
 	ocores_init(i2c);
 
 	init_waitqueue_head(&i2c->wait);
-	ret = devm_request_irq(&pdev->dev, res2->start, ocores_isr, 0,
+	ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0,
 			       pdev->name, i2c);
 	if (ret) {
 		dev_err(&pdev->dev, "Cannot claim IRQ\n");
-- 
1.7.0.4

[PATCH v4 2/2] i2c: i2c-ocores: Add support for the GRLIB port of the controller and custom getreg and setreg functions

[Andreas Larsson]

The registers in the GRLIB port of the controller are 32-bit and in big endian
byte order. The PRELOW and PREHIGH registers are merged into one register. The
subsequent registers have their offset decreased accordingly. Hence the register
access needs to be handled in a non-standard manner using custom getreg and
setreg functions.

A type is added as the data of the of match table entries. A new entry with a
different compatible string is added to the table. The type of that entry
triggers usage of the grlib functions.

Signed-off-by: Andreas Larsson <andreas-FkzTOoA/JUlBDgjK7y7TUQ@public.gmane.org>
---
 Changes since v3:
 - Use a separate entry in the of match table for the grlib variant and trigger
   grlib function usage on type put in the data field of that table entry

 .../devicetree/bindings/i2c/i2c-ocores.txt         |    2 +-
 drivers/i2c/busses/i2c-ocores.c                    |   79 +++++++++++++++++++-
 2 files changed, 77 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
index c15781f..1637c29 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
@@ -1,7 +1,7 @@
 Device tree configuration for i2c-ocores
 
 Required properties:
-- compatible      : "opencores,i2c-ocores"
+- compatible      : "opencores,i2c-ocores" or "aeroflexgaisler,i2cmst"
 - reg             : bus address start and address range size of device
 - interrupts      : interrupt number
 - clock-frequency : frequency of bus clock in Hz
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index 1d204cb..fc6e6e7 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -4,6 +4,9 @@
  *
  * Peter Korsgaard <jacmet-OfajU3CKLf1/SzgSGea1oA@public.gmane.org>
  *
+ * Support for the GRLIB port of the controller by
+ * Andreas Larsson <andreas-FkzTOoA/JUlBDgjK7y7TUQ@public.gmane.org>
+ *
  * This file is licensed under the terms of the GNU General Public License
  * version 2.  This program is licensed "as is" without any warranty of any
  * kind, whether express or implied.
@@ -38,6 +41,8 @@ struct ocores_i2c {
 	int nmsgs;
 	int state; /* see STATE_ */
 	int clock_khz;
+	void (*setreg)(struct ocores_i2c *i2c, int reg, u8 value);
+	u8 (*getreg)(struct ocores_i2c *i2c, int reg);
 };
 
 /* registers */
@@ -71,9 +76,14 @@ struct ocores_i2c {
 #define STATE_READ		3
 #define STATE_ERROR		4
 
+#define TYPE_OCORES		0
+#define TYPE_GRLIB		1
+
 static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
 {
-	if (i2c->reg_io_width == 4)
+	if (i2c->setreg)
+		i2c->setreg(i2c, reg, value);
+	else if (i2c->reg_io_width == 4)
 		iowrite32(value, i2c->base + (reg << i2c->reg_shift));
 	else if (i2c->reg_io_width == 2)
 		iowrite16(value, i2c->base + (reg << i2c->reg_shift));
@@ -83,7 +93,9 @@ static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
 
 static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
 {
-	if (i2c->reg_io_width == 4)
+	if (i2c->getreg)
+		return i2c->getreg(i2c, reg);
+	else if (i2c->reg_io_width == 4)
 		return ioread32(i2c->base + (reg << i2c->reg_shift));
 	else if (i2c->reg_io_width == 2)
 		return ioread16(i2c->base + (reg << i2c->reg_shift));
@@ -91,6 +103,40 @@ static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
 		return ioread8(i2c->base + (reg << i2c->reg_shift));
 }
 
+/* Read and write functions for the GRLIB port of the controller. Registers are
+ * 32-bit big endian and the PRELOW and PREHIGH registers are merged into one
+ * register. The subsequent registers has their offset decreased accordingly. */
+static u8 oc_getreg_grlib(struct ocores_i2c *i2c, int reg)
+{
+	u32 rd;
+	int rreg = reg;
+	if (reg != OCI2C_PRELOW)
+		rreg--;
+	rd = ioread32be(i2c->base + (rreg << i2c->reg_shift));
+	if (reg == OCI2C_PREHIGH)
+		return (u8)(rd >> 8);
+	else
+		return (u8)rd;
+}
+
+static void oc_setreg_grlib(struct ocores_i2c *i2c, int reg, u8 value)
+{
+	u32 curr, wr;
+	int rreg = reg;
+	if (reg != OCI2C_PRELOW)
+		rreg--;
+	if (reg == OCI2C_PRELOW || reg == OCI2C_PREHIGH) {
+		curr = ioread32be(i2c->base + (rreg << i2c->reg_shift));
+		if (reg == OCI2C_PRELOW)
+			wr = (curr & 0xff00) | value;
+		else
+			wr = (((u32)value) << 8) | (curr & 0xff);
+	} else {
+		wr = value;
+	}
+	iowrite32be(wr, i2c->base + (rreg << i2c->reg_shift));
+}
+
 static void ocores_process(struct ocores_i2c *i2c)
 {
 	struct i2c_msg *msg = i2c->msg;
@@ -228,6 +274,8 @@ static struct i2c_adapter ocores_adapter = {
 };
 
 #ifdef CONFIG_OF
+static int ocores_i2c_get_type(struct platform_device *pdev);
+
 static int ocores_i2c_of_probe(struct platform_device *pdev,
 				struct ocores_i2c *i2c)
 {
@@ -257,6 +305,13 @@ static int ocores_i2c_of_probe(struct platform_device *pdev,
 
 	of_property_read_u32(pdev->dev.of_node, "reg-io-width",
 				&i2c->reg_io_width);
+
+	if (ocores_i2c_get_type(pdev) == TYPE_GRLIB) {
+		dev_dbg(&pdev->dev, "GRLIB variant of i2c-ocores\n");
+		i2c->setreg = oc_setreg_grlib;
+		i2c->getreg = oc_getreg_grlib;
+	}
+
 	return 0;
 }
 #else
@@ -389,11 +444,29 @@ static SIMPLE_DEV_PM_OPS(ocores_i2c_pm, ocores_i2c_suspend, ocores_i2c_resume);
 #endif
 
 static struct of_device_id ocores_i2c_match[] = {
-	{ .compatible = "opencores,i2c-ocores", },
+	{
+		.compatible = "opencores,i2c-ocores",
+		.data = (void *)TYPE_OCORES,
+	},
+	{
+		.compatible = "aeroflexgaisler,i2cmst",
+		.data = (void *)TYPE_GRLIB,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, ocores_i2c_match);
 
+static int ocores_i2c_get_type(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+
+	match = of_match_node(ocores_i2c_match, pdev->dev.of_node);
+	if (match)
+		return (int)match->data;
+	else
+		return TYPE_OCORES;
+}
+
 static struct platform_driver ocores_i2c_driver = {
 	.probe   = ocores_i2c_probe,
 	.remove  = __devexit_p(ocores_i2c_remove),
-- 
1.7.0.4

Re: [PATCH v4 2/2] i2c: i2c-ocores: Add support for the GRLIB port of the controller and custom getreg and setreg functions

[Peter Korsgaard]

>>>>> "Andreas" == Andreas Larsson <andreas-FkzTOoA/JUlBDgjK7y7TUQ@public.gmane.org> writes:

Hi,

 Andreas> The registers in the GRLIB port of the controller are 32-bit
 Andreas> and in big endian byte order. The PRELOW and PREHIGH registers
 Andreas> are merged into one register. The subsequent registers have
 Andreas> their offset decreased accordingly. Hence the register access
 Andreas> needs to be handled in a non-standard manner using custom
 Andreas> getreg and setreg functions.

 Andreas> A type is added as the data of the of match table entries. A
 Andreas> new entry with a different compatible string is added to the
 Andreas> table. The type of that entry triggers usage of the grlib
 Andreas> functions.

 Andreas> Signed-off-by: Andreas Larsson <andreas-FkzTOoA/JUlBDgjK7y7TUQ@public.gmane.org>
 Andreas> ---
 Andreas>  Changes since v3:
 Andreas>  - Use a separate entry in the of match table for the grlib
 Andreas>  variant and trigger grlib function usage on type put in the
 Andreas>  data field of that table entry

Thanks. A few more comments:


 Andreas>  static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
 Andreas>  {
 Andreas> -	if (i2c->reg_io_width == 4)
 Andreas> +	if (i2c->setreg)
 Andreas> +		i2c->setreg(i2c, reg, value);
 Andreas> +	else if (i2c->reg_io_width == 4)
 Andreas>  		iowrite32(value, i2c->base + (reg << i2c->reg_shift));
 Andreas>  	else if (i2c->reg_io_width == 2)
 Andreas>  		iowrite16(value, i2c->base + (reg << i2c->reg_shift));

It would have been nice to add oc_getreg_8/16/32 functions and always
use the function pointers - But ok, that can be done later.

 
 Andreas>  #ifdef CONFIG_OF
 Andreas> +static int ocores_i2c_get_type(struct platform_device *pdev);
 Andreas> +

Why not just move the implementation up here instead of the forward
declaration?

 
 Andreas> +static int ocores_i2c_get_type(struct platform_device *pdev)
 Andreas> +{
 Andreas> +	const struct of_device_id *match;
 Andreas> +
 Andreas> +	match = of_match_node(ocores_i2c_match, pdev->dev.of_node);
 Andreas> +	if (match)
 Andreas> +		return (int)match->data;

Can this ever fail? If not, you might as well do the of_match_node
inline in the probe instead of this helper.

Other than that it looks good.

-- 
Bye, Peter Korsgaard