[PATCH v2 2/5] memory: stm32-fmc2-ebi: check regmap_read return value

From: Christophe Kerello
Date: Mon Feb 19 2024 - 09:04:38 EST


Check regmap_read return value to avoid to use uninitialized local
variables.

Signed-off-by: Christophe Kerello <christophe.kerello@xxxxxxxxxxx>
---
Changes in v2:
- New patch added

drivers/memory/stm32-fmc2-ebi.c | 128 +++++++++++++++++++++++---------
1 file changed, 94 insertions(+), 34 deletions(-)

diff --git a/drivers/memory/stm32-fmc2-ebi.c b/drivers/memory/stm32-fmc2-ebi.c
index 47d0ea5f1616..6eacfbdd300c 100644
--- a/drivers/memory/stm32-fmc2-ebi.c
+++ b/drivers/memory/stm32-fmc2-ebi.c
@@ -181,8 +181,11 @@ static int stm32_fmc2_ebi_check_mux(struct stm32_fmc2_ebi *ebi,
int cs)
{
u32 bcr;
+ int ret;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;

if (bcr & FMC2_BCR_MTYP)
return 0;
@@ -195,8 +198,11 @@ static int stm32_fmc2_ebi_check_waitcfg(struct stm32_fmc2_ebi *ebi,
int cs)
{
u32 bcr, val = FIELD_PREP(FMC2_BCR_MTYP, FMC2_BCR_MTYP_NOR);
+ int ret;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;

if ((bcr & FMC2_BCR_MTYP) == val && bcr & FMC2_BCR_BURSTEN)
return 0;
@@ -209,8 +215,11 @@ static int stm32_fmc2_ebi_check_sync_trans(struct stm32_fmc2_ebi *ebi,
int cs)
{
u32 bcr;
+ int ret;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;

if (bcr & FMC2_BCR_BURSTEN)
return 0;
@@ -223,8 +232,11 @@ static int stm32_fmc2_ebi_check_async_trans(struct stm32_fmc2_ebi *ebi,
int cs)
{
u32 bcr;
+ int ret;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;

if (!(bcr & FMC2_BCR_BURSTEN) || !(bcr & FMC2_BCR_CBURSTRW))
return 0;
@@ -237,8 +249,11 @@ static int stm32_fmc2_ebi_check_cpsize(struct stm32_fmc2_ebi *ebi,
int cs)
{
u32 bcr, val = FIELD_PREP(FMC2_BCR_MTYP, FMC2_BCR_MTYP_PSRAM);
+ int ret;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;

if ((bcr & FMC2_BCR_MTYP) == val && bcr & FMC2_BCR_BURSTEN)
return 0;
@@ -251,12 +266,18 @@ static int stm32_fmc2_ebi_check_address_hold(struct stm32_fmc2_ebi *ebi,
int cs)
{
u32 bcr, bxtr, val = FIELD_PREP(FMC2_BXTR_ACCMOD, FMC2_BXTR_EXTMOD_D);
+ int ret;
+
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
if (prop->reg_type == FMC2_REG_BWTR)
- regmap_read(ebi->regmap, FMC2_BWTR(cs), &bxtr);
+ ret = regmap_read(ebi->regmap, FMC2_BWTR(cs), &bxtr);
else
- regmap_read(ebi->regmap, FMC2_BTR(cs), &bxtr);
+ ret = regmap_read(ebi->regmap, FMC2_BTR(cs), &bxtr);
+ if (ret)
+ return ret;

if ((!(bcr & FMC2_BCR_BURSTEN) || !(bcr & FMC2_BCR_CBURSTRW)) &&
((bxtr & FMC2_BXTR_ACCMOD) == val || bcr & FMC2_BCR_MUXEN))
@@ -270,12 +291,19 @@ static int stm32_fmc2_ebi_check_clk_period(struct stm32_fmc2_ebi *ebi,
int cs)
{
u32 bcr, bcr1;
+ int ret;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
- if (cs)
- regmap_read(ebi->regmap, FMC2_BCR1, &bcr1);
- else
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;
+
+ if (cs) {
+ ret = regmap_read(ebi->regmap, FMC2_BCR1, &bcr1);
+ if (ret)
+ return ret;
+ } else {
bcr1 = bcr;
+ }

if (bcr & FMC2_BCR_BURSTEN && (!cs || !(bcr1 & FMC2_BCR1_CCLKEN)))
return 0;
@@ -307,12 +335,18 @@ static u32 stm32_fmc2_ebi_ns_to_clk_period(struct stm32_fmc2_ebi *ebi,
{
u32 nb_clk_cycles = stm32_fmc2_ebi_ns_to_clock_cycles(ebi, cs, setup);
u32 bcr, btr, clk_period;
+ int ret;
+
+ ret = regmap_read(ebi->regmap, FMC2_BCR1, &bcr);
+ if (ret)
+ return ret;

- regmap_read(ebi->regmap, FMC2_BCR1, &bcr);
if (bcr & FMC2_BCR1_CCLKEN || !cs)
- regmap_read(ebi->regmap, FMC2_BTR1, &btr);
+ ret = regmap_read(ebi->regmap, FMC2_BTR1, &btr);
else
- regmap_read(ebi->regmap, FMC2_BTR(cs), &btr);
+ ret = regmap_read(ebi->regmap, FMC2_BTR(cs), &btr);
+ if (ret)
+ return ret;

clk_period = FIELD_GET(FMC2_BTR_CLKDIV, btr) + 1;

@@ -571,11 +605,16 @@ static int stm32_fmc2_ebi_set_address_setup(struct stm32_fmc2_ebi *ebi,
if (ret)
return ret;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;
+
if (prop->reg_type == FMC2_REG_BWTR)
- regmap_read(ebi->regmap, FMC2_BWTR(cs), &bxtr);
+ ret = regmap_read(ebi->regmap, FMC2_BWTR(cs), &bxtr);
else
- regmap_read(ebi->regmap, FMC2_BTR(cs), &bxtr);
+ ret = regmap_read(ebi->regmap, FMC2_BTR(cs), &bxtr);
+ if (ret)
+ return ret;

if ((bxtr & FMC2_BXTR_ACCMOD) == val || bcr & FMC2_BCR_MUXEN)
val = clamp_val(setup, 1, FMC2_BXTR_ADDSET_MAX);
@@ -693,11 +732,14 @@ static int stm32_fmc2_ebi_set_max_low_pulse(struct stm32_fmc2_ebi *ebi,
int cs, u32 setup)
{
u32 old_val, new_val, pcscntr;
+ int ret;

if (setup < 1)
return 0;

- regmap_read(ebi->regmap, FMC2_PCSCNTR, &pcscntr);
+ ret = regmap_read(ebi->regmap, FMC2_PCSCNTR, &pcscntr);
+ if (ret)
+ return ret;

/* Enable counter for the bank */
regmap_update_bits(ebi->regmap, FMC2_PCSCNTR,
@@ -944,17 +986,26 @@ static void stm32_fmc2_ebi_disable_bank(struct stm32_fmc2_ebi *ebi, int cs)
regmap_update_bits(ebi->regmap, FMC2_BCR(cs), FMC2_BCR_MBKEN, 0);
}

-static void stm32_fmc2_ebi_save_setup(struct stm32_fmc2_ebi *ebi)
+static int stm32_fmc2_ebi_save_setup(struct stm32_fmc2_ebi *ebi)
{
unsigned int cs;
+ int ret;

for (cs = 0; cs < FMC2_MAX_EBI_CE; cs++) {
- regmap_read(ebi->regmap, FMC2_BCR(cs), &ebi->bcr[cs]);
- regmap_read(ebi->regmap, FMC2_BTR(cs), &ebi->btr[cs]);
- regmap_read(ebi->regmap, FMC2_BWTR(cs), &ebi->bwtr[cs]);
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &ebi->bcr[cs]);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(ebi->regmap, FMC2_BTR(cs), &ebi->btr[cs]);
+ if (ret)
+ return ret;
+
+ ret = regmap_read(ebi->regmap, FMC2_BWTR(cs), &ebi->bwtr[cs]);
+ if (ret)
+ return ret;
}

- regmap_read(ebi->regmap, FMC2_PCSCNTR, &ebi->pcscntr);
+ return regmap_read(ebi->regmap, FMC2_PCSCNTR, &ebi->pcscntr);
}

static void stm32_fmc2_ebi_set_setup(struct stm32_fmc2_ebi *ebi)
@@ -983,22 +1034,29 @@ static void stm32_fmc2_ebi_disable_banks(struct stm32_fmc2_ebi *ebi)
}

/* NWAIT signal can not be connected to EBI controller and NAND controller */
-static bool stm32_fmc2_ebi_nwait_used_by_ctrls(struct stm32_fmc2_ebi *ebi)
+static int stm32_fmc2_ebi_nwait_used_by_ctrls(struct stm32_fmc2_ebi *ebi)
{
+ struct device *dev = ebi->dev;
unsigned int cs;
u32 bcr;
+ int ret;

for (cs = 0; cs < FMC2_MAX_EBI_CE; cs++) {
if (!(ebi->bank_assigned & BIT(cs)))
continue;

- regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ ret = regmap_read(ebi->regmap, FMC2_BCR(cs), &bcr);
+ if (ret)
+ return ret;
+
if ((bcr & FMC2_BCR_WAITEN || bcr & FMC2_BCR_ASYNCWAIT) &&
- ebi->bank_assigned & BIT(FMC2_NAND))
- return true;
+ ebi->bank_assigned & BIT(FMC2_NAND)) {
+ dev_err(dev, "NWAIT signal connected to EBI and NAND controllers\n");
+ return -EINVAL;
+ }
}

- return false;
+ return 0;
}

static void stm32_fmc2_ebi_enable(struct stm32_fmc2_ebi *ebi)
@@ -1085,10 +1143,9 @@ static int stm32_fmc2_ebi_parse_dt(struct stm32_fmc2_ebi *ebi)
return -ENODEV;
}

- if (stm32_fmc2_ebi_nwait_used_by_ctrls(ebi)) {
- dev_err(dev, "NWAIT signal connected to EBI and NAND controllers\n");
- return -EINVAL;
- }
+ ret = stm32_fmc2_ebi_nwait_used_by_ctrls(ebi);
+ if (ret)
+ return ret;

stm32_fmc2_ebi_enable(ebi);

@@ -1133,7 +1190,10 @@ static int stm32_fmc2_ebi_probe(struct platform_device *pdev)
if (ret)
goto err_release;

- stm32_fmc2_ebi_save_setup(ebi);
+ ret = stm32_fmc2_ebi_save_setup(ebi);
+ if (ret)
+ goto err_release;
+
platform_set_drvdata(pdev, ebi);

return 0;
--
2.25.1