[PATCH v2 1/2] eeprom: at24: convert magic numbers to structs.
From: Sven Van Asbroeck
Date: Fri Dec 08 2017 - 16:25:40 EST
Fundamental properties such as capacity and page size differ
among at24-type chips. But these chips do not have an id register,
so this can't be discovered at runtime.
Traditionally, at24-type eeprom properties were determined in two ways:
- by passing a 'struct at24_platform_data' via platform_data, or
- by naming the chip type in the devicetree, which passes a
'magic number' to probe(), which is then converted to
a 'struct at24_platform_data'.
Recently a bug was discovered because the magic number rounds down
all chip sizes to the lowest power of two. This was addressed by
a work-around, with the wish that magic numbers should over time
be converted to structs.
This patch replaces the magic numbers with 'struct at24_chip_data'.
Signed-off-by: Sven Van Asbroeck <svendev@xxxxxxxx>
---
drivers/misc/eeprom/at24.c | 230 ++++++++++++++++++++++-----------------------
1 file changed, 110 insertions(+), 120 deletions(-)
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 06ffa11..c3759cb 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -105,16 +105,6 @@ struct at24_data {
module_param(write_timeout, uint, 0);
MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
-#define AT24_SIZE_BYTELEN 5
-#define AT24_SIZE_FLAGS 8
-
-#define AT24_BITMASK(x) (BIT(x) - 1)
-
-/* create non-zero magic value for given eeprom parameters */
-#define AT24_DEVICE_MAGIC(_len, _flags) \
- ((1 << AT24_SIZE_FLAGS | (_flags)) \
- << AT24_SIZE_BYTELEN | ilog2(_len))
-
/*
* Both reads and writes fail if the previous write didn't complete yet. This
* macro loops a few times waiting at least long enough for one entire page
@@ -131,113 +121,119 @@ struct at24_data {
op_time ? time_before(op_time, tout) : true; \
usleep_range(1000, 1500), op_time = jiffies)
+struct at24_chip_data {
+ /*
+ * these fields mirror their equivalents in
+ * struct at24_platform_data
+ */
+ u32 byte_len;
+ u8 flags;
+};
+
+#define AT24_CHIP_DATA(_name, _len, _flags) \
+ static const struct at24_chip_data at24_data_##_name = { \
+ .byte_len = _len, .flags = _flags, \
+ }
+
+#define AT24_I2C_DEVICE_ID(_name) \
+ { #_name, (kernel_ulong_t)&at24_data_##_name }
+
+#define AT24_ACPI_DEVICE_ID(_name) \
+ { #_name, (kernel_ulong_t)&at24_data_##_name }
+
+#define AT24_OF_DEVICE_ID(_of_compat, _name) \
+ { .compatible = _of_compat, .data = &at24_data_##_name }
+
+/* needs 8 addresses as A0-A2 are ignored */
+AT24_CHIP_DATA(24c00, 128 / 8, AT24_FLAG_TAKE8ADDR);
+/* old variants can't be handled with this generic entry! */
+AT24_CHIP_DATA(24c01, 1024 / 8, 0);
+AT24_CHIP_DATA(24cs01, 16, AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(24c02, 2048 / 8, 0);
+AT24_CHIP_DATA(24cs02, 16, AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(24mac402, 48 / 8,
+ AT24_FLAG_MAC | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(24mac602, 64 / 8,
+ AT24_FLAG_MAC | AT24_FLAG_READONLY);
+/* spd is a 24c02 in memory DIMMs */
+AT24_CHIP_DATA(spd, 2048 / 8,
+ AT24_FLAG_READONLY | AT24_FLAG_IRUGO);
+AT24_CHIP_DATA(24c04, 4096 / 8, 0);
+AT24_CHIP_DATA(24cs04, 16,
+ AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+/* 24rf08 quirk is handled at i2c-core */
+AT24_CHIP_DATA(24c08, 8192 / 8, 0);
+AT24_CHIP_DATA(24cs08, 16,
+ AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(24c16, 16384 / 8, 0);
+AT24_CHIP_DATA(24cs16, 16,
+ AT24_FLAG_SERIAL | AT24_FLAG_READONLY);
+AT24_CHIP_DATA(24c32, 32768 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(24cs32, 16,
+ AT24_FLAG_ADDR16 |
+ AT24_FLAG_SERIAL |
+ AT24_FLAG_READONLY);
+AT24_CHIP_DATA(24c64, 65536 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(24cs64, 16,
+ AT24_FLAG_ADDR16 |
+ AT24_FLAG_SERIAL |
+ AT24_FLAG_READONLY);
+AT24_CHIP_DATA(24c128, 131072 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(24c256, 262144 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(24c512, 524288 / 8, AT24_FLAG_ADDR16);
+AT24_CHIP_DATA(24c1024, 1048576 / 8, AT24_FLAG_ADDR16);
+/* identical to 24c08 ? */
+AT24_CHIP_DATA(INT3499, 8192 / 8, 0);
+
static const struct i2c_device_id at24_ids[] = {
- /* needs 8 addresses as A0-A2 are ignored */
- { "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) },
- /* old variants can't be handled with this generic entry! */
- { "24c01", AT24_DEVICE_MAGIC(1024 / 8, 0) },
- { "24cs01", AT24_DEVICE_MAGIC(16,
- AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
- { "24c02", AT24_DEVICE_MAGIC(2048 / 8, 0) },
- { "24cs02", AT24_DEVICE_MAGIC(16,
- AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
- { "24mac402", AT24_DEVICE_MAGIC(48 / 8,
- AT24_FLAG_MAC | AT24_FLAG_READONLY) },
- { "24mac602", AT24_DEVICE_MAGIC(64 / 8,
- AT24_FLAG_MAC | AT24_FLAG_READONLY) },
- /* spd is a 24c02 in memory DIMMs */
- { "spd", AT24_DEVICE_MAGIC(2048 / 8,
- AT24_FLAG_READONLY | AT24_FLAG_IRUGO) },
- { "24c04", AT24_DEVICE_MAGIC(4096 / 8, 0) },
- { "24cs04", AT24_DEVICE_MAGIC(16,
- AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
- /* 24rf08 quirk is handled at i2c-core */
- { "24c08", AT24_DEVICE_MAGIC(8192 / 8, 0) },
- { "24cs08", AT24_DEVICE_MAGIC(16,
- AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
- { "24c16", AT24_DEVICE_MAGIC(16384 / 8, 0) },
- { "24cs16", AT24_DEVICE_MAGIC(16,
- AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
- { "24c32", AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16) },
- { "24cs32", AT24_DEVICE_MAGIC(16,
- AT24_FLAG_ADDR16 |
- AT24_FLAG_SERIAL |
- AT24_FLAG_READONLY) },
- { "24c64", AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16) },
- { "24cs64", AT24_DEVICE_MAGIC(16,
- AT24_FLAG_ADDR16 |
- AT24_FLAG_SERIAL |
- AT24_FLAG_READONLY) },
- { "24c128", AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16) },
- { "24c256", AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16) },
- { "24c512", AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16) },
- { "24c1024", AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16) },
+ AT24_I2C_DEVICE_ID(24c00),
+ AT24_I2C_DEVICE_ID(24c01),
+ AT24_I2C_DEVICE_ID(24cs01),
+ AT24_I2C_DEVICE_ID(24c02),
+ AT24_I2C_DEVICE_ID(24cs02),
+ AT24_I2C_DEVICE_ID(24mac402),
+ AT24_I2C_DEVICE_ID(24mac602),
+ AT24_I2C_DEVICE_ID(spd),
+ AT24_I2C_DEVICE_ID(24c04),
+ AT24_I2C_DEVICE_ID(24cs04),
+ AT24_I2C_DEVICE_ID(24c08),
+ AT24_I2C_DEVICE_ID(24cs08),
+ AT24_I2C_DEVICE_ID(24c16),
+ AT24_I2C_DEVICE_ID(24cs16),
+ AT24_I2C_DEVICE_ID(24c32),
+ AT24_I2C_DEVICE_ID(24cs32),
+ AT24_I2C_DEVICE_ID(24c64),
+ AT24_I2C_DEVICE_ID(24cs64),
+ AT24_I2C_DEVICE_ID(24c128),
+ AT24_I2C_DEVICE_ID(24c256),
+ AT24_I2C_DEVICE_ID(24c512),
+ AT24_I2C_DEVICE_ID(24c1024),
{ "at24", 0 },
{ /* END OF LIST */ }
};
MODULE_DEVICE_TABLE(i2c, at24_ids);
static const struct of_device_id at24_of_match[] = {
- {
- .compatible = "atmel,24c00",
- .data = (void *)AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR)
- },
- {
- .compatible = "atmel,24c01",
- .data = (void *)AT24_DEVICE_MAGIC(1024 / 8, 0)
- },
- {
- .compatible = "atmel,24c02",
- .data = (void *)AT24_DEVICE_MAGIC(2048 / 8, 0)
- },
- {
- .compatible = "atmel,spd",
- .data = (void *)AT24_DEVICE_MAGIC(2048 / 8,
- AT24_FLAG_READONLY | AT24_FLAG_IRUGO)
- },
- {
- .compatible = "atmel,24c04",
- .data = (void *)AT24_DEVICE_MAGIC(4096 / 8, 0)
- },
- {
- .compatible = "atmel,24c08",
- .data = (void *)AT24_DEVICE_MAGIC(8192 / 8, 0)
- },
- {
- .compatible = "atmel,24c16",
- .data = (void *)AT24_DEVICE_MAGIC(16384 / 8, 0)
- },
- {
- .compatible = "atmel,24c32",
- .data = (void *)AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16)
- },
- {
- .compatible = "atmel,24c64",
- .data = (void *)AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16)
- },
- {
- .compatible = "atmel,24c128",
- .data = (void *)AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16)
- },
- {
- .compatible = "atmel,24c256",
- .data = (void *)AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16)
- },
- {
- .compatible = "atmel,24c512",
- .data = (void *)AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16)
- },
- {
- .compatible = "atmel,24c1024",
- .data = (void *)AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16)
- },
- { },
+ AT24_OF_DEVICE_ID("atmel,24c00", 24c00),
+ AT24_OF_DEVICE_ID("atmel,24c01", 24c01),
+ AT24_OF_DEVICE_ID("atmel,24c02", 24c02),
+ AT24_OF_DEVICE_ID("atmel,spd", spd),
+ AT24_OF_DEVICE_ID("atmel,24c04", 24c04),
+ AT24_OF_DEVICE_ID("atmel,24c08", 24c08),
+ AT24_OF_DEVICE_ID("atmel,24c16", 24c16),
+ AT24_OF_DEVICE_ID("atmel,24c32", 24c32),
+ AT24_OF_DEVICE_ID("atmel,24c64", 24c64),
+ AT24_OF_DEVICE_ID("atmel,24c128", 24c128),
+ AT24_OF_DEVICE_ID("atmel,24c256", 24c256),
+ AT24_OF_DEVICE_ID("atmel,24c512", 24c512),
+ AT24_OF_DEVICE_ID("atmel,24c1024", 24c1024),
+ { /* END OF LIST */ },
};
MODULE_DEVICE_TABLE(of, at24_of_match);
static const struct acpi_device_id at24_acpi_ids[] = {
- { "INT3499", AT24_DEVICE_MAGIC(8192 / 8, 0) },
- { }
+ AT24_ACPI_DEVICE_ID(INT3499),
+ { /* END OF LIST */ }
};
MODULE_DEVICE_TABLE(acpi, at24_acpi_ids);
@@ -525,8 +521,8 @@ static unsigned int at24_get_offset_adj(u8 flags, unsigned int byte_len)
static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
- struct at24_platform_data chip;
- kernel_ulong_t magic = 0;
+ struct at24_platform_data chip = { 0 };
+ const struct at24_chip_data *cd = NULL;
bool writable;
struct at24_data *at24;
int err;
@@ -544,28 +540,22 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id)
*/
if (client->dev.of_node &&
of_match_device(at24_of_match, &client->dev)) {
- magic = (kernel_ulong_t)
- of_device_get_match_data(&client->dev);
+ cd = of_device_get_match_data(&client->dev);
} else if (id) {
- magic = id->driver_data;
+ cd = (void *)id->driver_data;
} else {
const struct acpi_device_id *aid;
aid = acpi_match_device(at24_acpi_ids, &client->dev);
if (aid)
- magic = aid->driver_data;
+ cd = (void *)aid->driver_data;
}
- if (!magic)
+ if (!cd)
return -ENODEV;
- chip.byte_len = BIT(magic & AT24_BITMASK(AT24_SIZE_BYTELEN));
- magic >>= AT24_SIZE_BYTELEN;
- chip.flags = magic & AT24_BITMASK(AT24_SIZE_FLAGS);
-
+ chip.byte_len = cd->byte_len;
+ chip.flags = cd->flags;
at24_get_pdata(&client->dev, &chip);
-
- chip.setup = NULL;
- chip.context = NULL;
}
if (!is_power_of_2(chip.byte_len))
--
1.9.1