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From 2c2c7e16ad0401f85dd8ff9bc0789fa10e715c0e Mon Sep 17 00:00:00 2001
From: Clark Wang <xiaoning.wang@nxp.com>
Date: Tue, 15 Jan 2019 10:04:30 +0800
Subject: [PATCH] MLK-20368 i2c-imx: Coverity: fix divide by zero warning
"i2c_clk_rate / 2" might be zero when the i2c_clk_rate gets the clock is
0 or 1, so add a judgment to avoid the denominator is equal to 0.
Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
[Arul: Add support to check return value everywhere in the driver]
Signed-off-by: Arulpandiyan Vadivel <arulpandiyan_vadivel@mentor.com>
Signed-off-by: Shrikant Bobade <Shrikant_Bobade@mentor.com>
(cherry picked from commit d382de595bffc0975ab7c0582e08dd4f7afc0c1a)
(cherry picked from commit 456caa9ba270ca8f4f962918a0625d1a8348f316)
---
drivers/i2c/busses/i2c-imx.c | 31 +++++++++++++++++++++++++------
1 file changed, 25 insertions(+), 6 deletions(-)
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -514,16 +514,24 @@ static int i2c_imx_acked(struct imx_i2c_
return 0;
}
-static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
+static int i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
unsigned int i2c_clk_rate)
{
struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div;
unsigned int div;
int i;
- /* Divider value calculation */
if (i2c_imx->cur_clk == i2c_clk_rate)
- return;
+ return 0;
+
+ /*
+ * Keep the denominator of the following program
+ * always NOT equal to 0.
+ */
+
+ /* Divider value calculation */
+ if (!(i2c_clk_rate / 2))
+ return -EINVAL;
i2c_imx->cur_clk = i2c_clk_rate;
@@ -554,20 +562,23 @@ static void i2c_imx_set_clk(struct imx_i
dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n",
i2c_clk_div[i].val, i2c_clk_div[i].div);
#endif
+
+ return 0;
}
static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
unsigned long action, void *data)
{
+ int ret = 0;
struct clk_notifier_data *ndata = data;
struct imx_i2c_struct *i2c_imx = container_of(nb,
struct imx_i2c_struct,
clk_change_nb);
if (action & POST_RATE_CHANGE)
- i2c_imx_set_clk(i2c_imx, ndata->new_rate);
+ ret = i2c_imx_set_clk(i2c_imx, ndata->new_rate);
- return NOTIFY_OK;
+ return notifier_from_errno(ret);
}
static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
@@ -577,6 +588,10 @@ static int i2c_imx_start(struct imx_i2c_
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
+ result = i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
+ if (result)
+ return result;
+
imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
/* Enable I2C controller */
imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
@@ -1203,7 +1218,11 @@ static int i2c_imx_probe(struct platform
i2c_imx->bitrate = pdata->bitrate;
i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call;
clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb);
- i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
+ ret = i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk));
+ if (ret < 0) {
+ dev_err(&pdev->dev, "can't get I2C clock\n");
+ goto clk_notifier_unregister;
+ }
/*
* This limit caused by an i.MX7D hardware issue(e7805 in Errata).
|
