[PATCH v2 03/11] i2c: isch: Switch to memory mapped IO accessors

Andy Shevchenko
2024-09-16T12:02:42Z

Convert driver to use memory mapped IO accessors.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/i2c/busses/i2c-isch.c | 133 ++++++++++++++++++++--------------
1 file changed, 78 insertions(+), 55 deletions(-)

diff --git a/drivers/i2c/busses/i2c-isch.c b/drivers/i2c/busses/i2c-isch.c
index f44c5fa276dc..0eaefb7b8bca 100644
--- a/drivers/i2c/busses/i2c-isch.c
+++ b/drivers/i2c/busses/i2c-isch.c
@@ -24,16 +24,17 @@
#include <linux/io.h>
#include <linux/stddef.h>
#include <linux/string_choices.h>
+#include <linux/types.h>

/* SCH SMBus address offsets */
-#define SMBHSTCNT (0 + sch_smba)
-#define SMBHSTSTS (1 + sch_smba)
-#define SMBHSTCLK (2 + sch_smba)
-#define SMBHSTADD (4 + sch_smba) /* TSA */
-#define SMBHSTCMD (5 + sch_smba)
-#define SMBHSTDAT0 (6 + sch_smba)
-#define SMBHSTDAT1 (7 + sch_smba)
-#define SMBBLKDAT (0x20 + sch_smba)
+#define SMBHSTCNT 0x00
+#define SMBHSTSTS 0x01
+#define SMBHSTCLK 0x02
+#define SMBHSTADD 0x04 /* TSA */
+#define SMBHSTCMD 0x05
+#define SMBHSTDAT0 0x06
+#define SMBHSTDAT1 0x07
+#define SMBBLKDAT 0x20

/* Other settings */
#define MAX_RETRIES 5000
@@ -45,12 +46,33 @@
#define SCH_WORD_DATA 0x03
#define SCH_BLOCK_DATA 0x05

-static unsigned short sch_smba;
static struct i2c_adapter sch_adapter;
+static void __iomem *sch_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)
+{
+ return ioread8(smba + offset);
+}
+
+static inline void sch_io_wr8(void __iomem *smba, unsigned int offset, u8 value)
+{
+ iowrite8(value, smba + offset);
+}
+
+static inline u16 sch_io_rd16(void __iomem *smba, unsigned int offset)
+{
+ return ioread16(smba + offset);
+}
+
+static inline void sch_io_wr16(void __iomem *smba, unsigned int offset, u16 value)
+{
+ iowrite16(value, smba + offset);
+}
+
/*
* Start the i2c transaction -- the i2c_access will prepare the transaction
* and this function will execute it.
@@ -64,20 +86,20 @@ static int sch_transaction(struct i2c_adapter *adap)

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

/* Make sure the SMBus host is ready to start transmitting */
- temp = inb(SMBHSTSTS) & 0x0f;
+ temp = sch_io_rd8(sch_smba, 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);
- outb(temp, SMBHSTSTS);
- temp = inb(SMBHSTSTS) & 0x0f;
+ sch_io_wr8(sch_smba, SMBHSTSTS, temp);
+ temp = sch_io_rd8(sch_smba, SMBHSTSTS) & 0x0f;
if (temp) {
dev_err(&adap->dev, "SMBus is not ready: (%02x)\n", temp);
return -EAGAIN;
@@ -85,11 +107,13 @@ static int sch_transaction(struct i2c_adapter *adap)
}

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

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

/* If the SMBus is still busy, we give up */
@@ -105,8 +129,8 @@ 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");
- outb(temp, SMBHSTSTS);
- temp = inb(SMBHSTSTS) & 0x07;
+ sch_io_wr8(sch_smba, SMBHSTSTS, temp);
+ temp = sch_io_rd8(sch_smba, SMBHSTSTS) & 0x07;
if (temp & 0x06) {
/* Completion clear failed */
dev_dbg(&adap->dev,
@@ -117,9 +141,9 @@ 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",
- inb(SMBHSTCNT),
- inb(SMBHSTCMD), inb(SMBHSTADD), inb(SMBHSTDAT0),
- inb(SMBHSTDAT1));
+ 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));
return result;
}

@@ -137,12 +161,12 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr,
int i, len, temp, rc;

/* Make sure the SMBus host is not busy */
- temp = inb(SMBHSTSTS) & 0x0f;
+ temp = sch_io_rd8(sch_smba, SMBHSTSTS) & 0x0f;
if (temp & 0x08) {
dev_dbg(&adap->dev, "SMBus busy (%02x)\n", temp);
return -EAGAIN;
}
- temp = inw(SMBHSTCLK);
+ temp = sch_io_rd16(sch_smba, SMBHSTCLK);
if (!temp) {
/*
* We can't determine if we have 33 or 25 MHz clock for
@@ -151,47 +175,47 @@ 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");
- outw(backbone_speed / (4 * 100), SMBHSTCLK);
+ sch_io_wr16(sch_smba, 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:
- outb((addr << 1) | read_write, SMBHSTADD);
+ sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
size = SCH_QUICK;
break;
case I2C_SMBUS_BYTE:
- outb((addr << 1) | read_write, SMBHSTADD);
+ sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
if (read_write == I2C_SMBUS_WRITE)
- outb(command, SMBHSTCMD);
+ sch_io_wr8(sch_smba, SMBHSTCMD, command);
size = SCH_BYTE;
break;
case I2C_SMBUS_BYTE_DATA:
- outb((addr << 1) | read_write, SMBHSTADD);
- outb(command, SMBHSTCMD);
+ sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
+ sch_io_wr8(sch_smba, SMBHSTCMD, command);
if (read_write == I2C_SMBUS_WRITE)
- outb(data->byte, SMBHSTDAT0);
+ sch_io_wr8(sch_smba, SMBHSTDAT0, data->byte);
size = SCH_BYTE_DATA;
break;
case I2C_SMBUS_WORD_DATA:
- outb((addr << 1) | read_write, SMBHSTADD);
- outb(command, SMBHSTCMD);
+ sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
+ sch_io_wr8(sch_smba, SMBHSTCMD, command);
if (read_write == I2C_SMBUS_WRITE) {
- outb(data->word & 0xff, SMBHSTDAT0);
- outb((data->word & 0xff00) >> 8, SMBHSTDAT1);
+ sch_io_wr8(sch_smba, SMBHSTDAT0, data->word >> 0);
+ sch_io_wr8(sch_smba, SMBHSTDAT1, data->word >> 8);
}
size = SCH_WORD_DATA;
break;
case I2C_SMBUS_BLOCK_DATA:
- outb((addr << 1) | read_write, SMBHSTADD);
- outb(command, SMBHSTCMD);
+ sch_io_wr8(sch_smba, SMBHSTADD, (addr << 1) | read_write);
+ sch_io_wr8(sch_smba, SMBHSTCMD, command);
if (read_write == I2C_SMBUS_WRITE) {
len = data->block[0];
if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
return -EINVAL;
- outb(len, SMBHSTDAT0);
+ sch_io_wr8(sch_smba, SMBHSTDAT0, len);
for (i = 1; i <= len; i++)
- outb(data->block[i], SMBBLKDAT+i-1);
+ sch_io_wr8(sch_smba, SMBBLKDAT + i - 1, data->block[i]);
}
size = SCH_BLOCK_DATA;
break;
@@ -200,7 +224,10 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr,
return -EOPNOTSUPP;
}
dev_dbg(&adap->dev, "write size %d to 0x%04x\n", size, SMBHSTCNT);
- outb((inb(SMBHSTCNT) & 0xb0) | (size & 0x7), SMBHSTCNT);
+
+ temp = sch_io_rd8(sch_smba, SMBHSTCNT);
+ temp = (temp & 0xb0) | (size & 0x7);
+ sch_io_wr8(sch_smba, SMBHSTCNT, temp);

rc = sch_transaction(adap);
if (rc) /* Error in transaction */
@@ -212,17 +239,18 @@ static s32 sch_access(struct i2c_adapter *adap, u16 addr,
switch (size) {
case SCH_BYTE:
case SCH_BYTE_DATA:
- data->byte = inb(SMBHSTDAT0);
+ data->byte = sch_io_rd8(sch_smba, SMBHSTDAT0);
break;
case SCH_WORD_DATA:
- data->word = inb(SMBHSTDAT0) + (inb(SMBHSTDAT1) << 8);
+ data->word = (sch_io_rd8(sch_smba, SMBHSTDAT0) << 0) +
+ (sch_io_rd8(sch_smba, SMBHSTDAT1) << 8);
break;
case SCH_BLOCK_DATA:
- data->block[0] = inb(SMBHSTDAT0);
+ data->block[0] = sch_io_rd8(sch_smba, 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] = inb(SMBBLKDAT+i-1);
+ data->block[i] = sch_io_rd8(sch_smba, SMBBLKDAT + i - 1);
break;
}
return 0;
@@ -255,26 +283,21 @@ static int smbus_sch_probe(struct platform_device *dev)
if (!res)
return -EBUSY;

- if (!devm_request_region(&dev->dev, res->start, resource_size(res),
- dev->name)) {
- dev_err(&dev->dev, "SMBus region 0x%x already in use!\n",
- sch_smba);
+ sch_smba = devm_ioport_map(&dev->dev, res->start, resource_size(res));
+ if (!sch_smba) {
+ dev_err(&dev->dev, "SMBus region %pR already in use!\n", res);
return -EBUSY;
}

- sch_smba = res->start;
-
- dev_dbg(&dev->dev, "SMBA = 0x%X\n", sch_smba);
-
/* set up the sysfs linkage to our parent device */
sch_adapter.dev.parent = &dev->dev;

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

retval = i2c_add_adapter(&sch_adapter);
if (retval)
- sch_smba = 0;
+ sch_smba = NULL;

return retval;
}
@@ -283,7 +306,7 @@ static void smbus_sch_remove(struct platform_device *pdev)
{
if (sch_smba) {
i2c_del_adapter(&sch_adapter);
- sch_smba = 0;
+ sch_smba = NULL;
}
}

--
2.43.0.rc1.1336.g36b5255a03ac