[PATCH v1 05/12] i2c: isch: Use custom private data structure

From: Andy Shevchenko
Date: Wed Sep 11 2024 - 11:50:34 EST

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Use custom private data structure instead of global variables.
With that, remove not anymore true comment.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-isch.c | 145 ++++++++++++++++++----------------
1 file changed, 75 insertions(+), 70 deletions(-)

diff --git a/drivers/i2c/busses/i2c-isch.c b/drivers/i2c/busses/i2c-isch.c
index 8d34d4398f9b..4ec6c0a66a96 100644
--- a/drivers/i2c/busses/i2c-isch.c
+++ b/drivers/i2c/busses/i2c-isch.c
@@ -9,16 +9,14 @@

*/

-/*
- Supports:
- Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L)
- Note: we assume there can only be one device, with one SMBus interface.
-*/
+/* Supports: Intel SCH chipsets (AF82US15W, AF82US15L, AF82UL11L) */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/kernel.h>
+#include <linux/container_of.h>
#include <linux/delay.h>
+#include <linux/device.h>
#include <linux/ioport.h>
#include <linux/i2c.h>
#include <linux/io.h>
@@ -46,31 +44,33 @@
#define SCH_WORD_DATA 0x03
#define SCH_BLOCK_DATA 0x05

-static struct i2c_adapter sch_adapter;
-static void __iomem *sch_smba;
+struct sch_i2c {
+ struct i2c_adapter adapter;
+ void __iomem *smba;
+};

static int backbone_speed = 33000; /* backbone speed in kHz */
module_param(backbone_speed, int, S_IRUSR | S_IWUSR);
MODULE_PARM_DESC(backbone_speed, "Backbone speed in kHz, (default = 33000)");

-static inline u8 sch_io_rd8(void __iomem *smba, unsigned int offset)
+static inline u8 sch_io_rd8(struct sch_i2c *priv, unsigned int offset)
{
- return ioread8(smba + offset);
+ return ioread8(priv->smba + offset);
}

-static inline void sch_io_wr8(void __iomem *smba, unsigned int offset, u8 value)
+static inline void sch_io_wr8(struct sch_i2c *priv, unsigned int offset, u8 value)
{
- iowrite8(value, smba + offset);
+ iowrite8(value, priv->smba + offset);
}

-static inline u16 sch_io_rd16(void __iomem *smba, unsigned int offset)
+static inline u16 sch_io_rd16(struct sch_i2c *priv, unsigned int offset)
{
- return ioread16(smba + offset);
+ return ioread16(priv->smba + offset);
}

-static inline void sch_io_wr16(void __iomem *smba, unsigned int offset, u16 value)
+static inline void sch_io_wr16(struct sch_i2c *priv, unsigned int offset, u16 value)
{
- iowrite16(value, smba + offset);
+ iowrite16(value, priv->smba + offset);
}

/*
@@ -80,26 +80,27 @@ static inline void sch_io_wr16(void __iomem *smba, unsigned int offset, u16 valu
*/
static int sch_transaction(struct i2c_adapter *adap)
{
+ struct sch_i2c *priv = container_of(adap, struct sch_i2c, adapter);
int temp;
int result = 0;
int retries = 0;

dev_dbg(&adap->dev,
"Transaction (pre): CNT=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
- sch_io_rd8(sch_smba, SMBHSTCNT), sch_io_rd8(sch_smba, SMBHSTCMD),
- sch_io_rd8(sch_smba, SMBHSTADD),
- sch_io_rd8(sch_smba, SMBHSTDAT0), sch_io_rd8(sch_smba, SMBHSTDAT1));
+ sch_io_rd8(priv, SMBHSTCNT), sch_io_rd8(priv, SMBHSTCMD),
+ sch_io_rd8(priv, SMBHSTADD),
+ sch_io_rd8(priv, SMBHSTDAT0), sch_io_rd8(priv, SMBHSTDAT1));

/* Make sure the SMBus host is ready to start transmitting */
- temp = sch_io_rd8(sch_smba, SMBHSTSTS) & 0x0f;
+ temp = sch_io_rd8(priv, SMBHSTSTS) & 0x0f;
if (temp) {
/* Can not be busy since we checked it in sch_access */
if (temp & 0x01)
dev_dbg(&adap->dev, "Completion (%02x). Clear...\n", temp);
if (temp & 0x06)
dev_dbg(&adap->dev, "SMBus error (%02x). Resetting...\n", temp);
- sch_io_wr8(sch_smba, SMBHSTSTS, temp);
- temp = sch_io_rd8(sch_smba, SMBHSTSTS) & 0x0f;
+ sch_io_wr8(priv, SMBHSTSTS, temp);
+ temp = sch_io_rd8(priv, SMBHSTSTS) & 0x0f;
if (temp) {
dev_err(&adap->dev, "SMBus is not ready: (%02x)\n", temp);
return -EAGAIN;
@@ -107,13 +108,13 @@ static int sch_transaction(struct i2c_adapter *adap)
}

/* start the transaction by setting bit 4 */
- temp = sch_io_rd8(sch_smba, SMBHSTCNT);
+ temp = sch_io_rd8(priv, SMBHSTCNT);
temp |= 0x10;
- sch_io_wr8(sch_smba, SMBHSTCNT, temp);
+ sch_io_wr8(priv, SMBHSTCNT, temp);

do {
usleep_range(100, 200);
- temp = sch_io_rd8(sch_smba, SMBHSTSTS) & 0x0f;
+ temp = sch_io_rd8(priv, SMBHSTSTS) & 0x0f;
} while ((temp & 0x08) && (retries++ < MAX_RETRIES));

/* If the SMBus is still busy, we give up */
@@ -129,8 +130,8 @@ static int sch_transaction(struct i2c_adapter *adap)
dev_err(&adap->dev, "Error: no response!\n");
} else if (temp & 0x01) {
dev_dbg(&adap->dev, "Post complete!\n");
- sch_io_wr8(sch_smba, SMBHSTSTS, temp);
- temp = sch_io_rd8(sch_smba, SMBHSTSTS) & 0x07;
+ sch_io_wr8(priv, SMBHSTSTS, temp);
+ temp = sch_io_rd8(priv, SMBHSTSTS) & 0x07;
if (temp & 0x06) {
/* Completion clear failed */
dev_dbg(&adap->dev,
@@ -141,9 +142,9 @@ static int sch_transaction(struct i2c_adapter *adap)
dev_dbg(&adap->dev, "No such address.\n");
}
dev_dbg(&adap->dev, "Transaction (post): CNT=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
- sch_io_rd8(sch_smba, SMBHSTCNT), sch_io_rd8(sch_smba, SMBHSTCMD),
- sch_io_rd8(sch_smba, SMBHSTADD),
- sch_io_rd8(sch_smba, SMBHSTDAT0), sch_io_rd8(sch_smba, SMBHSTDAT1));
+ sch_io_rd8(priv, SMBHSTCNT), sch_io_rd8(priv, SMBHSTCMD),
+ sch_io_rd8(priv, SMBHSTADD),
+ sch_io_rd8(priv, SMBHSTDAT0), sch_io_rd8(priv, SMBHSTDAT1));
return result;
}

@@ -158,15 +159,16 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr,
unsigned short flags, char read_write,
u8 command, int size, union i2c_smbus_data *data)
{
+ struct sch_i2c *priv = container_of(adap, struct sch_i2c, adapter);
int i, len, temp, rc;

/* Make sure the SMBus host is not busy */
- temp = sch_io_rd8(sch_smba, SMBHSTSTS) & 0x0f;
+ temp = sch_io_rd8(priv, SMBHSTSTS) & 0x0f;
if (temp & 0x08) {
dev_dbg(&adap->dev, "SMBus busy (%02x)\n", temp);
return -EAGAIN;
}
- temp = sch_io_rd16(sch_smba, SMBHSTCLK);
+ temp = sch_io_rd16(priv, SMBHSTCLK);
if (!temp) {
/*
* We can't determine if we have 33 or 25 MHz clock for
@@ -175,47 +177,47 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr,
* run ~75 kHz instead which should do no harm.
*/
dev_notice(&adap->dev, "Clock divider uninitialized. Setting defaults\n");
- sch_io_wr16(sch_smba, SMBHSTCLK, backbone_speed / (4 * 100));
+ sch_io_wr16(priv, SMBHSTCLK, backbone_speed / (4 * 100));
}

dev_dbg(&adap->dev, "access size: %d %s\n", size, str_read_write(read_write));
switch (size) {
case I2C_SMBUS_QUICK:
- sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
+ sch_io_wr8(priv, SMBHSTADD, (addr << 1) | read_write);
size = SCH_QUICK;
break;
case I2C_SMBUS_BYTE:
- sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
+ sch_io_wr8(priv, SMBHSTADD, (addr << 1) | read_write);
if (read_write == I2C_SMBUS_WRITE)
- sch_io_wr8(sch_smba, SMBHSTCMD, command);
+ sch_io_wr8(priv, SMBHSTCMD, command);
size = SCH_BYTE;
break;
case I2C_SMBUS_BYTE_DATA:
- sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
- sch_io_wr8(sch_smba, SMBHSTCMD, command);
+ sch_io_wr8(priv, SMBHSTADD, (addr << 1) | read_write);
+ sch_io_wr8(priv, SMBHSTCMD, command);
if (read_write == I2C_SMBUS_WRITE)
- sch_io_wr8(sch_smba, SMBHSTDAT0, data->byte);
+ sch_io_wr8(priv, SMBHSTDAT0, data->byte);
size = SCH_BYTE_DATA;
break;
case I2C_SMBUS_WORD_DATA:
- sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
- sch_io_wr8(sch_smba, SMBHSTCMD, command);
+ sch_io_wr8(priv, SMBHSTADD, (addr << 1) | read_write);
+ sch_io_wr8(priv, SMBHSTCMD, command);
if (read_write == I2C_SMBUS_WRITE) {
- sch_io_wr8(sch_smba, SMBHSTDAT0, data->word >> 0);
- sch_io_wr8(sch_smba, SMBHSTDAT1, data->word >> 8);
+ sch_io_wr8(priv, SMBHSTDAT0, data->word >> 0);
+ sch_io_wr8(priv, SMBHSTDAT1, data->word >> 8);
}
size = SCH_WORD_DATA;
break;
case I2C_SMBUS_BLOCK_DATA:
- sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
- sch_io_wr8(sch_smba, SMBHSTCMD, command);
+ sch_io_wr8(priv, SMBHSTADD, (addr << 1) | read_write);
+ sch_io_wr8(priv, SMBHSTCMD, command);
if (read_write == I2C_SMBUS_WRITE) {
len = data->block[0];
if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
return -EINVAL;
- sch_io_wr8(sch_smba, SMBHSTDAT0, len);
+ sch_io_wr8(priv, SMBHSTDAT0, len);
for (i = 1; i <= len; i++)
- sch_io_wr8(sch_smba, SMBBLKDAT + i - 1, data->block[i]);
+ sch_io_wr8(priv, SMBBLKDAT + i - 1, data->block[i]);
}
size = SCH_BLOCK_DATA;
break;
@@ -225,9 +227,9 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr,
}
dev_dbg(&adap->dev, "write size %d to 0x%04x\n", size, SMBHSTCNT);

- temp = sch_io_rd8(sch_smba, SMBHSTCNT);
+ temp = sch_io_rd8(priv, SMBHSTCNT);
temp = (temp & 0xb0) | (size & 0x7);
- sch_io_wr8(sch_smba, SMBHSTCNT, temp);
+ sch_io_wr8(priv, SMBHSTCNT, temp);

rc = sch_transaction(adap);
if (rc) /* Error in transaction */
@@ -239,18 +241,18 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr,
switch (size) {
case SCH_BYTE:
case SCH_BYTE_DATA:
- data->byte = sch_io_rd8(sch_smba, SMBHSTDAT0);
+ data->byte = sch_io_rd8(priv, SMBHSTDAT0);
break;
case SCH_WORD_DATA:
- data->word = (sch_io_rd8(sch_smba, SMBHSTDAT0) << 0) +
- (sch_io_rd8(sch_smba, SMBHSTDAT1) << 8);
+ data->word = (sch_io_rd8(priv, SMBHSTDAT0) << 0) +
+ (sch_io_rd8(priv, SMBHSTDAT1) << 8);
break;
case SCH_BLOCK_DATA:
- data->block[0] = sch_io_rd8(sch_smba, SMBHSTDAT0);
+ data->block[0] = sch_io_rd8(priv, SMBHSTDAT0);
if (data->block[0] == 0 || data->block[0] > I2C_SMBUS_BLOCK_MAX)
return -EPROTO;
for (i = 1; i <= data->block[0]; i++)
- data->block[i] = sch_io_rd8(sch_smba, SMBBLKDAT + i - 1);
+ data->block[i] = sch_io_rd8(priv, SMBBLKDAT + i - 1);
break;
}
return 0;
@@ -268,46 +270,49 @@ static const struct i2c_algorithm smbus_algorithm = {
.functionality = sch_func,
};

-static struct i2c_adapter sch_adapter = {
- .owner = THIS_MODULE,
- .class = I2C_CLASS_HWMON,
- .algo = &smbus_algorithm,
-};
-
static int smbus_sch_probe(struct platform_device *dev)
{
+ struct sch_i2c *priv;
struct resource *res;
int retval;

+ priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
res = platform_get_resource(dev, IORESOURCE_IO, 0);
if (!res)
return -EBUSY;

- sch_smba = devm_ioport_map(&dev->dev, res->start, resource_size(res));
- if (!sch_smba) {
+ priv->smba = devm_ioport_map(&dev->dev, res->start, resource_size(res));
+ if (!priv->smba) {
dev_err(&dev->dev, "SMBus region %pR already in use!\n", res);
return -EBUSY;
}

/* set up the sysfs linkage to our parent device */
- sch_adapter.dev.parent = &dev->dev;
+ priv->adapter.dev.parent = &dev->dev;
+ priv->adapter.owner = THIS_MODULE,
+ priv->adapter.class = I2C_CLASS_HWMON,
+ priv->adapter.algo = &smbus_algorithm,

- snprintf(sch_adapter.name, sizeof(sch_adapter.name),
+ snprintf(priv->adapter.name, sizeof(priv->adapter.name),
"SMBus SCH adapter at %04x", res->start);

- retval = i2c_add_adapter(&sch_adapter);
+ retval = i2c_add_adapter(&priv->adapter);
if (retval)
- sch_smba = NULL;
+ return retval;

- return retval;
+ platform_set_drvdata(dev, priv);
+
+ return 0;
}

static void smbus_sch_remove(struct platform_device *pdev)
{
- if (sch_smba) {
- i2c_del_adapter(&sch_adapter);
- sch_smba = NULL;
- }
+ struct sch_i2c *priv = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&priv->adapter);
}

static struct platform_driver smbus_sch_driver = {
--
2.43.0.rc1.1336.g36b5255a03ac

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