drm/amd/display: Flatten unnecessary i2c functions

[Why]
The dce_i2c_hw code contained four funtcions that were only
called in one place and did not have a clearly delineated
purpose.

[How]
Inline these functions, keeping the same functionality.

This is not a functional change.

The functions disable_i2c_hw_engine and release_engine_dce_hw were
pulled into their respective callers.

The most interesting part of this change is the acquire functions.
dce_i2c_hw_engine_acquire_engine was pulled into
dce_i2c_engine_acquire_hw, and dce_i2c_engine_acquire_hw was pulled
into acquire_i2c_hw_engine.

Some notes to show that this change is not functional:
-Failure conditions in any function resulted in a cascade of calls that
ended in a 'return NULL'.
Those are replaced with a direct 'return NULL'.

-The variable result is the one from dce_i2c_hw_engine_acquire_engine.
The boolean result used as part of return logic was removed.

-As the second half of dce_i2c_hw_engine_acquire_engine is only executed
if that function is returning true and therefore exiting the do-while
loop in dce_i2c_engine_acquire_hw, those lines were moved outside
of the loop.

Signed-off-by: David Francis <David.Francis@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 34 insertions, 77 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_i2c_hw.c b/drivers/gpu/drm/amd/display/dc/dce/dce_i2c_hw.c
index 2800d3fa49da..40f2d6e0b122 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_i2c_hw.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_i2c_hw.c
@@ -36,12 +36,6 @@
 #define FN(reg_name, field_name) \
         dce_i2c_hw->shifts->field_name, dce_i2c_hw->masks->field_name
 
-static void disable_i2c_hw_engine(
-        struct dce_i2c_hw *dce_i2c_hw)
-{
-        REG_UPDATE_N(SETUP, 1, FN(SETUP, DC_I2C_DDC1_ENABLE), 0);
-}
-
 static void execute_transaction(
         struct dce_i2c_hw *dce_i2c_hw)
 {
@@ -348,60 +342,40 @@ static void release_engine(
                 REG_UPDATE(DC_I2C_CONTROL, DC_I2C_SW_STATUS_RESET, 1);
         /* HW I2c engine - clock gating feature */
         if (!dce_i2c_hw->engine_keep_power_up_count)
-                disable_i2c_hw_engine(dce_i2c_hw);
+                REG_UPDATE_N(SETUP, 1, FN(SETUP, DC_I2C_DDC1_ENABLE), 0);
 
 }
 
-static void release_engine_dce_hw(
+struct dce_i2c_hw *acquire_i2c_hw_engine(
         struct resource_pool *pool,
-        struct dce_i2c_hw *dce_i2c_hw)
-{
-        pool->i2c_hw_buffer_in_use = false;
-
-        release_engine(dce_i2c_hw);
-        dal_ddc_close(dce_i2c_hw->ddc);
-
-        dce_i2c_hw->ddc = NULL;
-}
-
-bool dce_i2c_hw_engine_acquire_engine(
-        struct dce_i2c_hw *dce_i2c_hw,
         struct ddc *ddc)
 {
-
+        uint32_t counter = 0;
         enum gpio_result result;
         uint32_t current_speed;
+        struct dce_i2c_hw *dce_i2c_hw = NULL;
 
-        result = dal_ddc_open(ddc, GPIO_MODE_HARDWARE,
-                GPIO_DDC_CONFIG_TYPE_MODE_I2C);
-
-        if (result != GPIO_RESULT_OK)
-                return false;
-
-        dce_i2c_hw->ddc = ddc;
-
-
-        current_speed = get_speed(dce_i2c_hw);
+        if (!ddc)
+                return NULL;
 
-        if (current_speed)
-                dce_i2c_hw->original_speed = current_speed;
+        if (ddc->hw_info.hw_supported) {
+                enum gpio_ddc_line line = dal_ddc_get_line(ddc);
 
-        return true;
-}
+                if (line < pool->pipe_count)
+                        dce_i2c_hw = pool->hw_i2cs[line];
+        }
 
-bool dce_i2c_engine_acquire_hw(
-        struct dce_i2c_hw *dce_i2c_hw,
-        struct ddc *ddc_handle)
-{
+        if (!dce_i2c_hw)
+                return NULL;
 
-        uint32_t counter = 0;
-        bool result;
+        if (pool->i2c_hw_buffer_in_use)
+                return NULL;
 
         do {
-                result = dce_i2c_hw_engine_acquire_engine(
-                                dce_i2c_hw, ddc_handle);
+                result = dal_ddc_open(ddc, GPIO_MODE_HARDWARE,
+                        GPIO_DDC_CONFIG_TYPE_MODE_I2C);
 
-                if (result)
+                if (result == GPIO_RESULT_OK)
                         break;
 
                 /* i2c_engine is busy by VBios, lets wait and retry */
@@ -411,45 +385,23 @@ bool dce_i2c_engine_acquire_hw(
                 ++counter;
         } while (counter < 2);
 
-        if (result) {
-                if (!setup_engine(dce_i2c_hw)) {
-                        release_engine(dce_i2c_hw);
-                        result = false;
-                }
-        }
-
-        return result;
-}
-
-struct dce_i2c_hw *acquire_i2c_hw_engine(
-        struct resource_pool *pool,
-        struct ddc *ddc)
-{
-
-        struct dce_i2c_hw *engine = NULL;
-
-        if (!ddc)
+        if (result != GPIO_RESULT_OK)
                 return NULL;
 
-        if (ddc->hw_info.hw_supported) {
-                enum gpio_ddc_line line = dal_ddc_get_line(ddc);
-
-                if (line < pool->pipe_count)
-                        engine = pool->hw_i2cs[line];
-        }
+        dce_i2c_hw->ddc = ddc;
 
-        if (!engine)
-                return NULL;
+        current_speed = get_speed(dce_i2c_hw);
 
+        if (current_speed)
+                dce_i2c_hw->original_speed = current_speed;
 
-        if (!pool->i2c_hw_buffer_in_use &&
-                        dce_i2c_engine_acquire_hw(engine, ddc)) {
-                pool->i2c_hw_buffer_in_use = true;
-                return engine;
+        if (!setup_engine(dce_i2c_hw)) {
+                release_engine(dce_i2c_hw);
+                return NULL;
         }
 
-
-        return NULL;
+        pool->i2c_hw_buffer_in_use = true;
+        return dce_i2c_hw;
 }
 
 enum i2c_channel_operation_result dce_i2c_hw_engine_wait_on_operation_result(
@@ -619,7 +571,12 @@ bool dce_i2c_submit_command_hw(
                 ++index_of_payload;
         }
 
-        release_engine_dce_hw(pool, dce_i2c_hw);
+        pool->i2c_hw_buffer_in_use = false;
+
+        release_engine(dce_i2c_hw);
+        dal_ddc_close(dce_i2c_hw->ddc);
+
+        dce_i2c_hw->ddc = NULL;
 
         return result;
 }