w1: ds2433: use the kernel bitmap implementation

The ds2433 driver uses the 'validcrc' variable to mark out which pages
have been successfully (crc is valid) retrieved from the eeprom and
placed in the internal 'memory' buffer (see CONFIG_W1_SLAVE_DS2433_CRC).

The current implementation assumes that the number of pages will never
go beyond 32 pages (bit field is a u32). This is fine for the ds2433
since it only has 16 pages.

On the ds28ec20 though, the number of pages increases to 80 which will
not fit on a single u32.

As a solution, I replaced the u32 variable with a standard bitmap and
set the number of bits to 32 which is the same size we had before.

Signed-off-by: Marc Ferland <marc.ferland@sonatest.com>
Link: https://lore.kernel.org/r/20231218150230.1992448-5-marc.ferland@sonatest.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

diff --git a/drivers/w1/slaves/w1_ds2433.c b/drivers/w1/slaves/w1_ds2433.c
index 0c67082..87df760 100644 (file)
--- a/drivers/w1/slaves/w1_ds2433.c
+++ b/drivers/w1/slaves/w1_ds2433.c
@@ -28,6 +28,7 @@
 #define W1_PAGE_SIZE           32
 #define W1_PAGE_BITS           5
 #define W1_PAGE_MASK           0x1F
+#define W1_VALIDCRC_MAX                32
 
 #define W1_F23_READ_EEPROM     0xF0
 #define W1_F23_WRITE_SCRATCH   0x0F
@@ -48,8 +49,8 @@ static const struct ds2433_config config_f23 = {
 
 struct w1_f23_data {
 #ifdef CONFIG_W1_SLAVE_DS2433_CRC
-       u8      *memory;
-       u32     validcrc;
+       u8 *memory;
+       DECLARE_BITMAP(validcrc, W1_VALIDCRC_MAX);
 #endif
        const struct ds2433_config *cfg;
 };
@@ -76,11 +77,11 @@ static int w1_f23_refresh_block(struct w1_slave *sl, struct w1_f23_data *data,
        u8      wrbuf[3];
        int     off = block * W1_PAGE_SIZE;
 
-       if (data->validcrc & (1 << block))
+       if (test_bit(block, data->validcrc))
                return 0;
 
        if (w1_reset_select_slave(sl)) {
-               data->validcrc = 0;
+               bitmap_zero(data->validcrc, data->cfg->page_count);
                return -EIO;
        }
 
@@ -92,7 +93,7 @@ static int w1_f23_refresh_block(struct w1_slave *sl, struct w1_f23_data *data,
 
        /* cache the block if the CRC is valid */
        if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
-               data->validcrc |= (1 << block);
+               set_bit(block, data->validcrc);
 
        return 0;
 }
@@ -207,7 +208,7 @@ static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data)
        /* Reset the bus to wake up the EEPROM (this may not be needed) */
        w1_reset_bus(sl->master);
 #ifdef CONFIG_W1_SLAVE_DS2433_CRC
-       f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
+       clear_bit(addr >> W1_PAGE_BITS, f23->validcrc);
 #endif
        return 0;
 }
@@ -290,11 +291,17 @@ static int w1_f23_add_slave(struct w1_slave *sl)
        data->cfg = &config_f23;
 
 #ifdef CONFIG_W1_SLAVE_DS2433_CRC
+       if (data->cfg->page_count > W1_VALIDCRC_MAX) {
+               dev_err(&sl->dev, "page count too big for crc bitmap\n");
+               kfree(data);
+               return -EINVAL;
+       }
        data->memory = kzalloc(data->cfg->eeprom_size, GFP_KERNEL);
        if (!data->memory) {
                kfree(data);
                return -ENOMEM;
        }
+       bitmap_zero(data->validcrc, data->cfg->page_count);
 #endif /* CONFIG_W1_SLAVE_DS2433_CRC */
        sl->family_data = data;