[U-Boot] [PATCH v2] fuelgauge: max17042: fix i2c read issue which causes infinity loop.
Przemyslaw Marczak
p.marczak at samsung.com
Mon Dec 30 11:24:32 CET 2013
Issues:
- reading i2c data by passing u16 pointer causes errors in read data.
- max17042 status register fields have not only Power On Reset meaning
so using proper mask is required.
Changes:
- read i2c data to type u32 instead of u16 - avoids buffer overflow
- compare FG status register using mask not just one bit value
- add checking return value to functions fg read/write
- add model lock and model check count
- add debug msg
Signed-off-by: Przemyslaw Marczak <p.marczak at samsung.com>
Cc: Lukasz Majewski <l.majewski at samsung.com>
Cc: Minkyu Kang <mk7.kang at samsung.com>
---
Changes v2:
- add checking return value to functions fg read/write
- add model lock and model check count
- add status msg
- change logical AND to bitwise AND when checking status register
drivers/power/fuel_gauge/fg_max17042.c | 120 +++++++++++++++++++++++---------
1 file changed, 86 insertions(+), 34 deletions(-)
diff --git a/drivers/power/fuel_gauge/fg_max17042.c b/drivers/power/fuel_gauge/fg_max17042.c
index c285747..154ca6a 100644
--- a/drivers/power/fuel_gauge/fg_max17042.c
+++ b/drivers/power/fuel_gauge/fg_max17042.c
@@ -20,21 +20,30 @@ static int fg_write_regs(struct pmic *p, u8 addr, u16 *data, int num)
int ret = 0;
int i;
- for (i = 0; i < num; i++, addr++)
- ret |= pmic_reg_write(p, addr, *(data + i));
+ for (i = 0; i < num; i++, addr++) {
+ ret = pmic_reg_write(p, addr, *(data + i));
+ if (ret)
+ return ret;
+ }
- return ret;
+ return 0;
}
static int fg_read_regs(struct pmic *p, u8 addr, u16 *data, int num)
{
+ unsigned int dat;
int ret = 0;
int i;
- for (i = 0; i < num; i++, addr++)
- ret |= pmic_reg_read(p, addr, (u32 *) (data + i));
+ for (i = 0; i < num; i++, addr++) {
+ ret = pmic_reg_read(p, addr, &dat);
+ if (ret)
+ return ret;
- return ret;
+ *(data + i) = (u16)dat;
+ }
+
+ return 0;
}
static int fg_write_and_verify(struct pmic *p, u8 addr, u16 data)
@@ -57,9 +66,13 @@ static int fg_write_and_verify(struct pmic *p, u8 addr, u16 data)
static void por_fuelgauge_init(struct pmic *p)
{
u16 r_data0[16], r_data1[16], r_data2[16];
- u32 rewrite_count = 5, i = 0;
- unsigned int val;
- int ret = 0;
+ u32 rewrite_count = 5;
+ u32 check_count;
+ u32 lock_count;
+ u32 i = 0;
+ u32 val;
+ s32 ret = 0;
+ char *status_msg;
/* Delay 500 ms */
mdelay(500);
@@ -67,29 +80,55 @@ static void por_fuelgauge_init(struct pmic *p)
pmic_reg_write(p, MAX17042_CONFIG, 0x2310);
rewrite_model:
+ check_count = 5;
+ lock_count = 5;
+
+ if (!rewrite_count--) {
+ status_msg = "init failed!";
+ goto error;
+ }
+
/* Unlock Model Access */
pmic_reg_write(p, MAX17042_MLOCKReg1, MODEL_UNLOCK1);
pmic_reg_write(p, MAX17042_MLOCKReg2, MODEL_UNLOCK2);
/* Write/Read/Verify the Custom Model */
- ret |= fg_write_regs(p, MAX17042_MODEL1, cell_character0,
+ ret = fg_write_regs(p, MAX17042_MODEL1, cell_character0,
ARRAY_SIZE(cell_character0));
- ret |= fg_write_regs(p, MAX17042_MODEL2, cell_character1,
+ if (ret)
+ goto rewrite_model;
+
+ ret = fg_write_regs(p, MAX17042_MODEL2, cell_character1,
ARRAY_SIZE(cell_character1));
- ret |= fg_write_regs(p, MAX17042_MODEL3, cell_character2,
+ if (ret)
+ goto rewrite_model;
+
+ ret = fg_write_regs(p, MAX17042_MODEL3, cell_character2,
ARRAY_SIZE(cell_character2));
+ if (ret)
+ goto rewrite_model;
- if (ret) {
- printf("%s: Cell parameters write failed!\n", __func__);
- return;
+check_model:
+ if (!check_count--) {
+ if (rewrite_count)
+ goto rewrite_model;
+ else
+ status_msg = "check failed!";
+
+ goto error;
}
- ret |= fg_read_regs(p, MAX17042_MODEL1, r_data0, ARRAY_SIZE(r_data0));
- ret |= fg_read_regs(p, MAX17042_MODEL2, r_data1, ARRAY_SIZE(r_data1));
- ret |= fg_read_regs(p, MAX17042_MODEL3, r_data2, ARRAY_SIZE(r_data2));
+ ret = fg_read_regs(p, MAX17042_MODEL1, r_data0, ARRAY_SIZE(r_data0));
+ if (ret)
+ goto check_model;
+
+ ret = fg_read_regs(p, MAX17042_MODEL2, r_data1, ARRAY_SIZE(r_data1));
+ if (ret)
+ goto check_model;
+ ret = fg_read_regs(p, MAX17042_MODEL3, r_data2, ARRAY_SIZE(r_data2));
if (ret)
- printf("%s: Cell parameters read failed!\n", __func__);
+ goto check_model;
for (i = 0; i < 16; i++) {
if ((cell_character0[i] != r_data0[i])
@@ -98,29 +137,37 @@ rewrite_model:
goto rewrite_model;
}
+lock_model:
+ if (!lock_count--) {
+ if (rewrite_count)
+ goto rewrite_model;
+ else
+ status_msg = "lock failed!";
+
+ goto error;
+ }
+
/* Lock model access */
pmic_reg_write(p, MAX17042_MLOCKReg1, MODEL_LOCK1);
pmic_reg_write(p, MAX17042_MLOCKReg2, MODEL_LOCK2);
/* Verify the model access is locked */
- ret |= fg_read_regs(p, MAX17042_MODEL1, r_data0, ARRAY_SIZE(r_data0));
- ret |= fg_read_regs(p, MAX17042_MODEL2, r_data1, ARRAY_SIZE(r_data1));
- ret |= fg_read_regs(p, MAX17042_MODEL3, r_data2, ARRAY_SIZE(r_data2));
+ ret = fg_read_regs(p, MAX17042_MODEL1, r_data0, ARRAY_SIZE(r_data0));
+ if (ret)
+ goto lock_model;
- if (ret) {
- printf("%s: Cell parameters read failed!\n", __func__);
- return;
- }
+ ret = fg_read_regs(p, MAX17042_MODEL2, r_data1, ARRAY_SIZE(r_data1));
+ if (ret)
+ goto lock_model;
+
+ ret = fg_read_regs(p, MAX17042_MODEL3, r_data2, ARRAY_SIZE(r_data2));
+ if (ret)
+ goto lock_model;
for (i = 0; i < ARRAY_SIZE(r_data0); i++) {
/* Check if model locked */
- if (r_data0[i] || r_data1[i] || r_data2[i]) {
- /* Rewrite model data - prevent from endless loop */
- if (rewrite_count--) {
- puts("FG - Lock model access failed!\n");
- goto rewrite_model;
- }
- }
+ if (r_data0[i] || r_data1[i] || r_data2[i])
+ goto lock_model;
}
/* Write Custom Parameters */
@@ -137,6 +184,11 @@ rewrite_model:
/* Delay at least 350 ms */
mdelay(350);
+
+ status_msg = "OK!";
+error:
+ debug("%s: model init status: %s\n", p->name, status_msg);
+ return;
}
static int power_update_battery(struct pmic *p, struct pmic *bat)
@@ -178,7 +230,7 @@ static int power_check_battery(struct pmic *p, struct pmic *bat)
ret |= pmic_reg_read(p, MAX17042_STATUS, &val);
debug("fg status: 0x%x\n", val);
- if (val == MAX17042_POR)
+ if (val & MAX17042_POR)
por_fuelgauge_init(p);
ret |= pmic_reg_read(p, MAX17042_VERSION, &val);
--
1.7.9.5
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