From: Lewis Huang Date: Fri, 10 Jan 2020 16:51:15 +0000 (+0800) Subject: drm/amd/display: Refine i2c frequency calculating sequence X-Git-Tag: v5.6-rc1~34^2^2~55 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=9eeec26a13392d6efb5215c26b5e9965ef7ac2af;p=linux.git drm/amd/display: Refine i2c frequency calculating sequence [Why] In HG mode, vbios didn't call DispController_Init to program NV1x XTAL_REF_DIV value when ASIC_INIT, but driver read XTAL_REF_DIV to calculate i2c reference frequency. it cause i2c frequency change from 100kHz to 200kHz. [How] remove get_speed function and calculate reference frequency at set_speed functiton. Signed-off-by: Lewis Huang Reviewed-by: Jun Lei Acked-by: Bhawanpreet Lakha Signed-off-by: Alex Deucher --- 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 1cd4d8fc361f..49d490214060 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 @@ -100,20 +100,6 @@ static uint32_t get_hw_buffer_available_size( dce_i2c_hw->buffer_used_bytes; } -static uint32_t get_speed( - const struct dce_i2c_hw *dce_i2c_hw) -{ - uint32_t pre_scale = 0; - - REG_GET(SPEED, DC_I2C_DDC1_PRESCALE, &pre_scale); - - /* [anaumov] it seems following is unnecessary */ - /*ASSERT(value.bits.DC_I2C_DDC1_PRESCALE);*/ - return pre_scale ? - dce_i2c_hw->reference_frequency / pre_scale : - dce_i2c_hw->default_speed; -} - static void process_channel_reply( struct dce_i2c_hw *dce_i2c_hw, struct i2c_payload *reply) @@ -278,16 +264,25 @@ static void set_speed( struct dce_i2c_hw *dce_i2c_hw, uint32_t speed) { + uint32_t xtal_ref_div = 0; + uint32_t prescale = 0; + + REG_GET(MICROSECOND_TIME_BASE_DIV, XTAL_REF_DIV, &xtal_ref_div); + + if (xtal_ref_div == 0) + xtal_ref_div = 2; + + prescale = ((dce_i2c_hw->reference_frequency * 2) / xtal_ref_div) / speed; if (speed) { if (dce_i2c_hw->masks->DC_I2C_DDC1_START_STOP_TIMING_CNTL) REG_UPDATE_N(SPEED, 3, - FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), dce_i2c_hw->reference_frequency / speed, + FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), prescale, FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_THRESHOLD), 2, FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_START_STOP_TIMING_CNTL), speed > 50 ? 2:1); else REG_UPDATE_N(SPEED, 2, - FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), dce_i2c_hw->reference_frequency / speed, + FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_PRESCALE), prescale, FN(DC_I2C_DDC1_SPEED, DC_I2C_DDC1_THRESHOLD), 2); } } @@ -344,9 +339,7 @@ static void release_engine( bool safe_to_reset; /* Restore original HW engine speed */ - - set_speed(dce_i2c_hw, dce_i2c_hw->original_speed); - + REG_WRITE(SPEED, dce_i2c_hw->original_speed); /* Reset HW engine */ { @@ -416,7 +409,7 @@ struct dce_i2c_hw *acquire_i2c_hw_engine( dce_i2c_hw->ddc = ddc; - current_speed = get_speed(dce_i2c_hw); + current_speed = REG_READ(SPEED); if (current_speed) dce_i2c_hw->original_speed = current_speed; @@ -478,13 +471,9 @@ static void submit_channel_request_hw( static uint32_t get_transaction_timeout_hw( const struct dce_i2c_hw *dce_i2c_hw, - uint32_t length) + uint32_t length, + uint32_t speed) { - - uint32_t speed = get_speed(dce_i2c_hw); - - - uint32_t period_timeout; uint32_t num_of_clock_stretches; @@ -504,7 +493,8 @@ static uint32_t get_transaction_timeout_hw( bool dce_i2c_hw_engine_submit_payload( struct dce_i2c_hw *dce_i2c_hw, struct i2c_payload *payload, - bool middle_of_transaction) + bool middle_of_transaction, + uint32_t speed) { struct i2c_request_transaction_data request; @@ -542,7 +532,7 @@ bool dce_i2c_hw_engine_submit_payload( /* obtain timeout value before submitting request */ transaction_timeout = get_transaction_timeout_hw( - dce_i2c_hw, payload->length + 1); + dce_i2c_hw, payload->length + 1, speed); submit_channel_request_hw( dce_i2c_hw, &request); @@ -588,13 +578,11 @@ bool dce_i2c_submit_command_hw( struct i2c_payload *payload = cmd->payloads + index_of_payload; if (!dce_i2c_hw_engine_submit_payload( - dce_i2c_hw, payload, mot)) { + dce_i2c_hw, payload, mot, cmd->speed)) { result = false; break; } - - ++index_of_payload; } @@ -640,9 +628,6 @@ void dce100_i2c_hw_construct( const struct dce_i2c_shift *shifts, const struct dce_i2c_mask *masks) { - - uint32_t xtal_ref_div = 0; - dce_i2c_hw_construct(dce_i2c_hw, ctx, engine_id, @@ -650,21 +635,6 @@ void dce100_i2c_hw_construct( shifts, masks); dce_i2c_hw->buffer_size = I2C_HW_BUFFER_SIZE_DCE100; - - REG_GET(MICROSECOND_TIME_BASE_DIV, XTAL_REF_DIV, &xtal_ref_div); - - if (xtal_ref_div == 0) - xtal_ref_div = 2; - - /*Calculating Reference Clock by divding original frequency by - * XTAL_REF_DIV. - * At upper level, uint32_t reference_frequency = - * dal_dce_i2c_get_reference_clock(as) >> 1 - * which already divided by 2. So we need x2 to get original - * reference clock from ppll_info - */ - dce_i2c_hw->reference_frequency = - (dce_i2c_hw->reference_frequency * 2) / xtal_ref_div; } void dce112_i2c_hw_construct(