mfd: intel_quark_i2c_gpio: Don't crash if !DMI

dmi_get_system_info() may return NULL either when CONFIG_DMI is not set or when
board has an old firmware. The patch prevents a crash and changes the default
frequency to be in align with older board.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[Lee: Removed overt "sentinel" comment and extra lines]
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/mfd/intel_quark_i2c_gpio.c b/drivers/mfd/intel_quark_i2c_gpio.c
index 006f2a1b1b1e..1ce16037d043 100644
--- a/drivers/mfd/intel_quark_i2c_gpio.c
+++ b/drivers/mfd/intel_quark_i2c_gpio.c
@@ -70,6 +70,7 @@ static const struct i2c_mode_info platform_i2c_mode_info[] = {
                 .name = "GalileoGen2",
                 .i2c_scl_freq = 400000,
         },
+        {}
 };
 
 static struct resource intel_quark_i2c_res[] = {
@@ -153,10 +154,10 @@ static void intel_quark_unregister_i2c_clk(struct pci_dev *pdev)
 static int intel_quark_i2c_setup(struct pci_dev *pdev, struct mfd_cell *cell)
 {
         const char *board_name = dmi_get_system_info(DMI_BOARD_NAME);
+        const struct i2c_mode_info *info;
         struct dw_i2c_platform_data *pdata;
         struct resource *res = (struct resource *)cell->resources;
         struct device *dev = &pdev->dev;
-        unsigned int i;
 
         res[INTEL_QUARK_IORES_MEM].start =
                 pci_resource_start(pdev, MFD_I2C_BAR);
@@ -170,13 +171,17 @@ static int intel_quark_i2c_setup(struct pci_dev *pdev, struct mfd_cell *cell)
         if (!pdata)
                 return -ENOMEM;
 
-        /* Fast mode by default */
-        pdata->i2c_scl_freq = 400000;
-
-        for (i = 0; i < ARRAY_SIZE(platform_i2c_mode_info); i++)
-                if (!strcmp(board_name, platform_i2c_mode_info[i].name))
-                        pdata->i2c_scl_freq
-                                = platform_i2c_mode_info[i].i2c_scl_freq;
+        /* Normal mode by default */
+        pdata->i2c_scl_freq = 100000;
+
+        if (board_name) {
+                for (info = platform_i2c_mode_info; info->name; info++) {
+                        if (!strcmp(board_name, info->name)) {
+                                pdata->i2c_scl_freq = info->i2c_scl_freq;
+                                break;
+                        }
+                }
+        }
 
         cell->platform_data = pdata;
         cell->pdata_size = sizeof(*pdata);