[v5,7/8] i2c: iproc: add NIC I2C support

Commit Message

Ray Jui Feb. 14, 2019, 5:57 p.m. UTC

From: Rayagonda Kokatanur <[e-mail]>

Add NIC I2C support to the iProc I2C driver. Access to the NIC I2C base
registers requires going through the IDM wrapper to map into the NIC's
address space

Signed-off-by: Rayagonda Kokatanur <[e-mail]>
Signed-off-by: Ray Jui <[e-mail]>
---
 drivers/i2c/busses/i2c-bcm-iproc.c | 79 ++++++++++++++++++++++++++++--
 1 file changed, 75 insertions(+), 4 deletions(-)

Comments

Wolfram Sang April 2, 2019, 10:27 a.m. UTC | #1

> +#define IDM_CTRL_DIRECT_OFFSET       0x00

And this IDM thing is also never used outside of the I2C context? In
other words, it also doesn't need a seperate DT node?


> +	/* indicates no slave mode support */
> +	bool no_slave;

I would suggest to not use a flag, but to nullify the {un}reg_slave
callbacks in probe depending on the type. That will also tell the
i2c-core that slave functionality is not supported. And you can use if
(!algo->reg_slave) as a flag, too.

> +	iproc_i2c->type =
> +		(enum bcm_iproc_i2c_type) of_device_get_match_data(&pdev->dev);

No need to cast a void*.

Ray Jui April 2, 2019, 5:57 p.m. UTC | #2

On 4/2/2019 3:27 AM, Wolfram Sang wrote:
> 
>> +#define IDM_CTRL_DIRECT_OFFSET       0x00
> 
> And this IDM thing is also never used outside of the I2C context? In
> other words, it also doesn't need a seperate DT node?
> 
> 

That is correct. Only in the I2C context in our use case.

>> +	/* indicates no slave mode support */
>> +	bool no_slave;
> 
> I would suggest to not use a flag, but to nullify the {un}reg_slave
> callbacks in probe depending on the type. That will also tell the
> i2c-core that slave functionality is not supported. And you can use if
> (!algo->reg_slave) as a flag, too.
> 

Yes. Great idea. I'll make the change and remove reg_slave.

>> +	iproc_i2c->type =
>> +		(enum bcm_iproc_i2c_type) of_device_get_match_data(&pdev->dev);
> 
> No need to cast a void*.
> 

Yes will fix.

Thanks,

Ray

Ray Jui April 3, 2019, 1:10 a.m. UTC | #3

On 4/2/2019 10:57 AM, Ray Jui wrote:
> 
> 
> On 4/2/2019 3:27 AM, Wolfram Sang wrote:

[...]

>>> +	iproc_i2c->type =
>>> +		(enum bcm_iproc_i2c_type) of_device_get_match_data(&pdev->dev);
>>
>> No need to cast a void*.
>>

In fact, we do need to type cast here since 'iproc_i2c->type' is NOT a
pointer:

drivers/i2c/busses/i2c-bcm-iproc.c:870:18: error: incompatible types
when assigning to type ‘enum bcm_iproc_i2c_type’ from type ‘const void *’
  iproc_i2c->type = of_device_get_match_data(&pdev->dev);
                  ^
> 
> Yes will fix.
> 
> Thanks,
> 
> Ray
>

Patch

diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index 5b9cbd7a3776..9598e1d0048e 100644
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -17,9 +17,11 @@ 
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
+#define IDM_CTRL_DIRECT_OFFSET       0x00
 #define CFG_OFFSET                   0x00
 #define CFG_RESET_SHIFT              31
 #define CFG_EN_SHIFT                 30
@@ -174,11 +176,26 @@  enum bus_speed_index {
 	I2C_SPD_400K,
 };
 
+enum bcm_iproc_i2c_type {
+	IPROC_I2C,
+	IPROC_I2C_NIC
+};
+
 struct bcm_iproc_i2c_dev {
 	struct device *device;
+	enum bcm_iproc_i2c_type type;
 	int irq;
 
 	void __iomem *base;
+	void __iomem *idm_base;
+
+	u32 ape_addr_mask;
+
+	/* lock for indirect access through IDM */
+	spinlock_t idm_lock;
+
+	/* indicates no slave mode support */
+	bool no_slave;
 
 	struct i2c_adapter adapter;
 	unsigned int bus_speed;
@@ -215,13 +232,33 @@  static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
 static inline u32 iproc_i2c_rd_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
 				   u32 offset)
 {
-	return readl(iproc_i2c->base + offset);
+	u32 val;
+
+	if (iproc_i2c->idm_base) {
+		spin_lock(&iproc_i2c->idm_lock);
+		writel(iproc_i2c->ape_addr_mask,
+		       iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
+		val = readl(iproc_i2c->base + offset);
+		spin_unlock(&iproc_i2c->idm_lock);
+	} else {
+		val = readl(iproc_i2c->base + offset);
+	}
+
+	return val;
 }
 
 static inline void iproc_i2c_wr_reg(struct bcm_iproc_i2c_dev *iproc_i2c,
 				    u32 offset, u32 val)
 {
-	writel(val, iproc_i2c->base + offset);
+	if (iproc_i2c->idm_base) {
+		spin_lock(&iproc_i2c->idm_lock);
+		writel(iproc_i2c->ape_addr_mask,
+		       iproc_i2c->idm_base + IDM_CTRL_DIRECT_OFFSET);
+		writel(val, iproc_i2c->base + offset);
+		spin_unlock(&iproc_i2c->idm_lock);
+	} else {
+		writel(val, iproc_i2c->base + offset);
+	}
 }
 
 static void bcm_iproc_i2c_slave_init(
@@ -766,7 +803,13 @@  static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter,
 
 static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SLAVE;
+	struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adap);
+	u32 val = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+
+	if (!iproc_i2c->no_slave)
+		val |= I2C_FUNC_SLAVE;
+
+	return val;
 }
 
 static const struct i2c_algorithm bcm_iproc_algo = {
@@ -829,6 +872,8 @@  static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, iproc_i2c);
 	iproc_i2c->device = &pdev->dev;
+	iproc_i2c->type =
+		(enum bcm_iproc_i2c_type) of_device_get_match_data(&pdev->dev);
 	init_completion(&iproc_i2c->done);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -836,6 +881,26 @@  static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 	if (IS_ERR(iproc_i2c->base))
 		return PTR_ERR(iproc_i2c->base);
 
+	if (iproc_i2c->type == IPROC_I2C_NIC) {
+		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+		iproc_i2c->idm_base = devm_ioremap_resource(iproc_i2c->device,
+							    res);
+		if (IS_ERR(iproc_i2c->idm_base))
+			return PTR_ERR(iproc_i2c->idm_base);
+
+		ret = of_property_read_u32(iproc_i2c->device->of_node,
+					   "brcm,ape-hsls-addr-mask",
+					   &iproc_i2c->ape_addr_mask);
+		if (ret < 0) {
+			dev_err(iproc_i2c->device,
+				"'brcm,ape-hsls-addr-mask' missing\n");
+			return -EINVAL;
+		}
+
+		spin_lock_init(&iproc_i2c->idm_lock);
+		iproc_i2c->no_slave = true;
+	}
+
 	ret = bcm_iproc_i2c_init(iproc_i2c);
 	if (ret)
 		return ret;
@@ -992,7 +1057,13 @@  static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave)
 }
 
 static const struct of_device_id bcm_iproc_i2c_of_match[] = {
-	{ .compatible = "brcm,iproc-i2c" },
+	{
+		.compatible = "brcm,iproc-i2c",
+		.data = (int *)IPROC_I2C,
+	}, {
+		.compatible = "brcm,iproc-nic-i2c",
+		.data = (int *)IPROC_I2C_NIC,
+	},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match);