clk: ti: fix ti_clk_get_reg_addr error handling

There is a case where NULL can be a valid return value for
ti_clk_get_reg_addr, specifically the case where both the provider index
and register offsets are zero. In this case, the current error checking
against a NULL pointer will fail. Thus, change the API to return a
ERR_PTR value in an error case, and change all the users of this API to
check against IS_ERR instead.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Michael Turquette <mturquette@linaro.org>

8 files changed, 18 insertions, 16 deletions

diff --git a/drivers/clk/ti/apll.c b/drivers/clk/ti/apll.c
index 72d97279eae1..49baf3831546 100644
--- a/drivers/clk/ti/apll.c
+++ b/drivers/clk/ti/apll.c
@@ -203,7 +203,7 @@ static void __init of_dra7_apll_setup(struct device_node *node)
         ad->control_reg = ti_clk_get_reg_addr(node, 0);
         ad->idlest_reg = ti_clk_get_reg_addr(node, 1);
 
-        if (!ad->control_reg || !ad->idlest_reg)
+        if (IS_ERR(ad->control_reg) || IS_ERR(ad->idlest_reg))
                 goto cleanup;
 
         ad->idlest_mask = 0x1;
@@ -384,7 +384,8 @@ static void __init of_omap2_apll_setup(struct device_node *node)
         ad->autoidle_reg = ti_clk_get_reg_addr(node, 1);
         ad->idlest_reg = ti_clk_get_reg_addr(node, 2);
 
-        if (!ad->control_reg || !ad->autoidle_reg || !ad->idlest_reg)
+        if (IS_ERR(ad->control_reg) || IS_ERR(ad->autoidle_reg) ||
+            IS_ERR(ad->idlest_reg))
                 goto cleanup;
 
         clk = clk_register(NULL, &clk_hw->hw);
diff --git a/drivers/clk/ti/autoidle.c b/drivers/clk/ti/autoidle.c
index 8912ff80af34..e75c64c9e81c 100644
--- a/drivers/clk/ti/autoidle.c
+++ b/drivers/clk/ti/autoidle.c
@@ -119,7 +119,7 @@ int __init of_ti_clk_autoidle_setup(struct device_node *node)
         clk->name = node->name;
         clk->reg = ti_clk_get_reg_addr(node, 0);
 
-        if (!clk->reg) {
+        if (IS_ERR(clk->reg)) {
                 kfree(clk);
                 return -EINVAL;
         }
diff --git a/drivers/clk/ti/clk.c b/drivers/clk/ti/clk.c
index e22b95646e09..0ebe5c51062b 100644
--- a/drivers/clk/ti/clk.c
+++ b/drivers/clk/ti/clk.c
@@ -103,7 +103,8 @@ int __init ti_clk_retry_init(struct device_node *node, struct clk_hw *hw,
  * @index: register index from the clock node
  *
  * Builds clock register address from device tree information. This
- * is a struct of type clk_omap_reg.
+ * is a struct of type clk_omap_reg. Returns a pointer to the register
+ * address, or a pointer error value in failure.
  */
 void __iomem *ti_clk_get_reg_addr(struct device_node *node, int index)
 {
@@ -121,14 +122,14 @@ void __iomem *ti_clk_get_reg_addr(struct device_node *node, int index)
 
         if (i == CLK_MAX_MEMMAPS) {
                 pr_err("clk-provider not found for %s!\n", node->name);
-                return NULL;
+                return ERR_PTR(-ENOENT);
         }
 
         reg->index = i;
 
         if (of_property_read_u32_index(node, "reg", index, &val)) {
                 pr_err("%s must have reg[%d]!\n", node->name, index);
-                return NULL;
+                return ERR_PTR(-EINVAL);
         }
 
         reg->offset = val;
diff --git a/drivers/clk/ti/divider.c b/drivers/clk/ti/divider.c
index 6211893c0980..ff5f117950a9 100644
--- a/drivers/clk/ti/divider.c
+++ b/drivers/clk/ti/divider.c
@@ -530,8 +530,8 @@ static int __init ti_clk_divider_populate(struct device_node *node,
         u32 val;
 
         *reg = ti_clk_get_reg_addr(node, 0);
-        if (!*reg)
-                return -EINVAL;
+        if (IS_ERR(*reg))
+                return PTR_ERR(*reg);
 
         if (!of_property_read_u32(node, "ti,bit-shift", &val))
                 *shift = val;
diff --git a/drivers/clk/ti/dpll.c b/drivers/clk/ti/dpll.c
index 81dc4698dc41..11478a501c30 100644
--- a/drivers/clk/ti/dpll.c
+++ b/drivers/clk/ti/dpll.c
@@ -390,18 +390,18 @@ static void __init of_ti_dpll_setup(struct device_node *node,
 #endif
         } else {
                 dd->idlest_reg = ti_clk_get_reg_addr(node, 1);
-                if (!dd->idlest_reg)
+                if (IS_ERR(dd->idlest_reg))
                         goto cleanup;
 
                 dd->mult_div1_reg = ti_clk_get_reg_addr(node, 2);
         }
 
-        if (!dd->control_reg || !dd->mult_div1_reg)
+        if (IS_ERR(dd->control_reg) || IS_ERR(dd->mult_div1_reg))
                 goto cleanup;
 
         if (dd->autoidle_mask) {
                 dd->autoidle_reg = ti_clk_get_reg_addr(node, 3);
-                if (!dd->autoidle_reg)
+                if (IS_ERR(dd->autoidle_reg))
                         goto cleanup;
         }
 
diff --git a/drivers/clk/ti/gate.c b/drivers/clk/ti/gate.c
index d493307b73f4..0c6fdfcd5f93 100644
--- a/drivers/clk/ti/gate.c
+++ b/drivers/clk/ti/gate.c
@@ -225,7 +225,7 @@ static void __init _of_ti_gate_clk_setup(struct device_node *node,
 
         if (ops != &omap_gate_clkdm_clk_ops) {
                 reg = ti_clk_get_reg_addr(node, 0);
-                if (!reg)
+                if (IS_ERR(reg))
                         return;
 
                 if (!of_property_read_u32(node, "ti,bit-shift", &val))
@@ -264,7 +264,7 @@ _of_ti_composite_gate_clk_setup(struct device_node *node,
                 return;
 
         gate->enable_reg = ti_clk_get_reg_addr(node, 0);
-        if (!gate->enable_reg)
+        if (IS_ERR(gate->enable_reg))
                 goto cleanup;
 
         of_property_read_u32(node, "ti,bit-shift", &val);
diff --git a/drivers/clk/ti/interface.c b/drivers/clk/ti/interface.c
index 265d91f071c5..c76230d8dd04 100644
--- a/drivers/clk/ti/interface.c
+++ b/drivers/clk/ti/interface.c
@@ -111,7 +111,7 @@ static void __init _of_ti_interface_clk_setup(struct device_node *node,
         u32 val;
 
         reg = ti_clk_get_reg_addr(node, 0);
-        if (!reg)
+        if (IS_ERR(reg))
                 return;
 
         if (!of_property_read_u32(node, "ti,bit-shift", &val))
diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c
index 728e253606bc..5cdeed538b08 100644
--- a/drivers/clk/ti/mux.c
+++ b/drivers/clk/ti/mux.c
@@ -210,7 +210,7 @@ static void of_mux_clk_setup(struct device_node *node)
 
         reg = ti_clk_get_reg_addr(node, 0);
 
-        if (!reg)
+        if (IS_ERR(reg))
                 goto cleanup;
 
         of_property_read_u32(node, "ti,bit-shift", &shift);
@@ -283,7 +283,7 @@ static void __init of_ti_composite_mux_clk_setup(struct device_node *node)
 
         mux->reg = ti_clk_get_reg_addr(node, 0);
 
-        if (!mux->reg)
+        if (IS_ERR(mux->reg))
                 goto cleanup;
 
         if (!of_property_read_u32(node, "ti,bit-shift", &val))