[Intel-gfx] [PATCH] drm/i915/bxt: Additional MIPI clock divider form B0 stepping onwards

Jani Nikula jani.nikula at linux.intel.com
Fri Feb 19 09:18:27 UTC 2016


On Wed, 17 Feb 2016, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> On Mon, 15 Feb 2016, Deepak M <m.deepak at intel.com> wrote:
>> The MIPI clock calculations for the addtional clock
>> are revised from B0 stepping onwards, the bit definitions
>> have changed compared to old stepping.
>>
>> v2: Fixing compilation warning.
>> v3: Retained the old Macros (Jani)
>>
>> Signed-off-by: Deepak M <m.deepak at intel.com>
>
> Reviewed-by: Jani Nikula <jani.nikula at intel.com>

The problem here is that we have no Tested-by on B0+ hardware for this.

>
>
>> ---
>>  drivers/gpu/drm/i915/i915_reg.h      | 96 +++++++++++++++++++-----------------
>>  drivers/gpu/drm/i915/intel_dsi_pll.c | 56 ++++++++++++++-------
>>  2 files changed, 89 insertions(+), 63 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 144586e..4e61b06 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -7663,58 +7663,62 @@ enum skl_disp_power_wells {
>>  #define  BXT_MIPI_DIV_SHIFT(port)		\
>>  			_MIPI_PORT(port, BXT_MIPI1_DIV_SHIFT, \
>>  					BXT_MIPI2_DIV_SHIFT)
>> -/* Var clock divider to generate TX source. Result must be < 39.5 M */
>> -#define  BXT_MIPI1_ESCLK_VAR_DIV_MASK		(0x3F << 26)
>> -#define  BXT_MIPI2_ESCLK_VAR_DIV_MASK		(0x3F << 10)
>> -#define  BXT_MIPI_ESCLK_VAR_DIV_MASK(port)	\
>> -			_MIPI_PORT(port, BXT_MIPI1_ESCLK_VAR_DIV_MASK, \
>> -						BXT_MIPI2_ESCLK_VAR_DIV_MASK)
>> -
>> -#define  BXT_MIPI_ESCLK_VAR_DIV(port, val)	\
>> -			(val << BXT_MIPI_DIV_SHIFT(port))
>> +
>>  /* TX control divider to select actual TX clock output from (8x/var) */
>> -#define  BXT_MIPI1_TX_ESCLK_SHIFT		21
>> -#define  BXT_MIPI2_TX_ESCLK_SHIFT		5
>> +#define  BXT_MIPI1_TX_ESCLK_SHIFT		26
>> +#define  BXT_MIPI2_TX_ESCLK_SHIFT		10
>>  #define  BXT_MIPI_TX_ESCLK_SHIFT(port)		\
>>  			_MIPI_PORT(port, BXT_MIPI1_TX_ESCLK_SHIFT, \
>>  					BXT_MIPI2_TX_ESCLK_SHIFT)
>> -#define  BXT_MIPI1_TX_ESCLK_FIXDIV_MASK		(3 << 21)
>> -#define  BXT_MIPI2_TX_ESCLK_FIXDIV_MASK		(3 << 5)
>> +#define  BXT_MIPI1_TX_ESCLK_FIXDIV_MASK		(0x3F << 26)
>> +#define  BXT_MIPI2_TX_ESCLK_FIXDIV_MASK		(0x3F << 10)
>>  #define  BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port)	\
>>  			_MIPI_PORT(port, BXT_MIPI1_TX_ESCLK_FIXDIV_MASK, \
>> -						BXT_MIPI2_TX_ESCLK_FIXDIV_MASK)
>> -#define  BXT_MIPI_TX_ESCLK_8XDIV_BY2(port)	\
>> -		(0x0 << BXT_MIPI_TX_ESCLK_SHIFT(port))
>> -#define  BXT_MIPI_TX_ESCLK_8XDIV_BY4(port)	\
>> -		(0x1 << BXT_MIPI_TX_ESCLK_SHIFT(port))
>> -#define  BXT_MIPI_TX_ESCLK_8XDIV_BY8(port)	\
>> -		(0x2 << BXT_MIPI_TX_ESCLK_SHIFT(port))
>> -/* RX control divider to select actual RX clock output from 8x*/
>> -#define  BXT_MIPI1_RX_ESCLK_SHIFT		19
>> -#define  BXT_MIPI2_RX_ESCLK_SHIFT		3
>> -#define  BXT_MIPI_RX_ESCLK_SHIFT(port)		\
>> -			_MIPI_PORT(port, BXT_MIPI1_RX_ESCLK_SHIFT, \
>> -					BXT_MIPI2_RX_ESCLK_SHIFT)
>> -#define  BXT_MIPI1_RX_ESCLK_FIXDIV_MASK		(3 << 19)
>> -#define  BXT_MIPI2_RX_ESCLK_FIXDIV_MASK		(3 << 3)
>> -#define  BXT_MIPI_RX_ESCLK_FIXDIV_MASK(port)	\
>> -		(3 << BXT_MIPI_RX_ESCLK_SHIFT(port))
>> -#define  BXT_MIPI_RX_ESCLK_8X_BY2(port)	\
>> -		(1 << BXT_MIPI_RX_ESCLK_SHIFT(port))
>> -#define  BXT_MIPI_RX_ESCLK_8X_BY3(port)	\
>> -		(2 << BXT_MIPI_RX_ESCLK_SHIFT(port))
>> -#define  BXT_MIPI_RX_ESCLK_8X_BY4(port)	\
>> -		(3 << BXT_MIPI_RX_ESCLK_SHIFT(port))
>> -/* BXT-A WA: Always prog DPHY dividers to 00 */
>> -#define  BXT_MIPI1_DPHY_DIV_SHIFT		16
>> -#define  BXT_MIPI2_DPHY_DIV_SHIFT		0
>> -#define  BXT_MIPI_DPHY_DIV_SHIFT(port)		\
>> -			_MIPI_PORT(port, BXT_MIPI1_DPHY_DIV_SHIFT, \
>> -					BXT_MIPI2_DPHY_DIV_SHIFT)
>> -#define  BXT_MIPI_1_DPHY_DIVIDER_MASK		(3 << 16)
>> -#define  BXT_MIPI_2_DPHY_DIVIDER_MASK		(3 << 0)
>> -#define  BXT_MIPI_DPHY_DIVIDER_MASK(port)	\
>> -		(3 << BXT_MIPI_DPHY_DIV_SHIFT(port))
>> +					BXT_MIPI2_TX_ESCLK_FIXDIV_MASK)
>> +#define  BXT_MIPI_TX_ESCLK_DIVIDER(port, val)	\
>> +		((val & 0x3F) << BXT_MIPI_TX_ESCLK_SHIFT(port))
>> +/* RX upper control divider to select actual RX clock output from 8x*/
>> +#define  BXT_MIPI1_RX_ESCLK_UPPER_SHIFT		21
>> +#define  BXT_MIPI2_RX_ESCLK_UPPER_SHIFT		5
>> +#define  BXT_MIPI_RX_ESCLK_UPPER_SHIFT(port)		\
>> +			_MIPI_PORT(port, BXT_MIPI1_RX_ESCLK_UPPER_SHIFT, \
>> +					BXT_MIPI2_RX_ESCLK_UPPER_SHIFT)
>> +#define  BXT_MIPI1_RX_ESCLK_UPPER_FIXDIV_MASK		(3 << 21)
>> +#define  BXT_MIPI2_RX_ESCLK_UPPER_FIXDIV_MASK		(3 << 5)
>> +#define  BXT_MIPI_RX_ESCLK_UPPER_FIXDIV_MASK(port) 	\
>> +			_MIPI_PORT(port, BXT_MIPI1_RX_ESCLK_UPPER_FIXDIV_MASK,\
>> +					BXT_MIPI2_RX_ESCLK_UPPER_FIXDIV_MASK)
>> +#define  BXT_MIPI_RX_ESCLK_UPPER_DIVIDER(port, val)	\
>> +		((val & 3) << BXT_MIPI_RX_ESCLK_UPPER_SHIFT(port))
>> +/* 8/3X divider to select the actual 8/3X clock output from 8x*/
>> +#define  BXT_MIPI1_8X_BY3_SHIFT                19
>> +#define  BXT_MIPI2_8X_BY3_SHIFT                3
>> +#define  BXT_MIPI_8X_BY3_SHIFT(port)          \
>> +			_MIPI_PORT(port, BXT_MIPI1_8X_BY3_SHIFT, \
>> +					BXT_MIPI2_8X_BY3_SHIFT)
>> +#define  BXT_MIPI1_8X_BY3_DIVIDER_MASK         (3 << 19)
>> +#define  BXT_MIPI2_8X_BY3_DIVIDER_MASK         (3 << 3)
>> +#define  BXT_MIPI_8X_BY3_DIVIDER_MASK(port)    \
>> +			_MIPI_PORT(port, BXT_MIPI1_8X_BY3_DIVIDER_MASK, \
>> +						BXT_MIPI2_8X_BY3_DIVIDER_MASK)
>> +#define  BXT_MIPI_8X_BY3_DIVIDER(port, val)    \
>> +			((val & 3) << BXT_MIPI_8X_BY3_SHIFT(port))
>> +/* RX lower control divider to select actual RX clock output from 8x*/
>> +#define  BXT_MIPI1_RX_ESCLK_LOWER_SHIFT		16
>> +#define  BXT_MIPI2_RX_ESCLK_LOWER_SHIFT		0
>> +#define  BXT_MIPI_RX_ESCLK_LOWER_SHIFT(port)		\
>> +			_MIPI_PORT(port, BXT_MIPI1_RX_ESCLK_LOWER_SHIFT, \
>> +					BXT_MIPI2_RX_ESCLK_LOWER_SHIFT)
>> +#define  BXT_MIPI1_RX_ESCLK_LOWER_FIXDIV_MASK		(3 << 16)
>> +#define  BXT_MIPI2_RX_ESCLK_LOWER_FIXDIV_MASK		(3 << 0)
>> +#define  BXT_MIPI_RX_ESCLK_LOWER_FIXDIV_MASK(port)	\
>> +			_MIPI_PORT(port, BXT_MIPI1_RX_ESCLK_LOWER_FIXDIV_MASK, \
>> +					BXT_MIPI2_RX_ESCLK_LOWER_FIXDIV_MASK)
>> +#define  BXT_MIPI_RX_ESCLK_LOWER_DIVIDER(port, val)	\
>> +		((val & 3) << BXT_MIPI_RX_ESCLK_LOWER_SHIFT(port))
>> +
>> +#define RX_DIVIDER_BIT_1_2                     0x3
>> +#define RX_DIVIDER_BIT_3_4                     0xC
>>  
>>  /* BXT MIPI mode configure */
>>  #define  _BXT_MIPIA_TRANS_HACTIVE			0x6B0F8
>> diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c
>> index bb5e95a..02aeae5 100644
>> --- a/drivers/gpu/drm/i915/intel_dsi_pll.c
>> +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c
>> @@ -362,35 +362,57 @@ static void vlv_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
>>  /* Program BXT Mipi clocks and dividers */
>>  static void bxt_dsi_program_clocks(struct drm_device *dev, enum port port)
>>  {
>> -	u32 tmp;
>> -	u32 divider;
>> -	u32 dsi_rate;
>> -	u32 pll_ratio;
>>  	struct drm_i915_private *dev_priv = dev->dev_private;
>> +	u32 tmp;
>> +	u32 dsi_rate = 0;
>> +	u32 pll_ratio = 0;
>> +	u32 rx_div;
>> +	u32 tx_div;
>> +	u32 rx_div_upper;
>> +	u32 rx_div_lower;
>> +	u32 mipi_8by3_divider;
>>  
>>  	/* Clear old configurations */
>>  	tmp = I915_READ(BXT_MIPI_CLOCK_CTL);
>>  	tmp &= ~(BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port));
>> -	tmp &= ~(BXT_MIPI_RX_ESCLK_FIXDIV_MASK(port));
>> -	tmp &= ~(BXT_MIPI_ESCLK_VAR_DIV_MASK(port));
>> -	tmp &= ~(BXT_MIPI_DPHY_DIVIDER_MASK(port));
>> +	tmp &= ~(BXT_MIPI_RX_ESCLK_UPPER_FIXDIV_MASK(port));
>> +	tmp &= ~(BXT_MIPI_8X_BY3_DIVIDER_MASK(port));
>> +	tmp &= ~(BXT_MIPI_RX_ESCLK_LOWER_FIXDIV_MASK(port));
>>  
>>  	/* Get the current DSI rate(actual) */
>>  	pll_ratio = I915_READ(BXT_DSI_PLL_CTL) &
>>  				BXT_DSI_PLL_RATIO_MASK;
>>  	dsi_rate = (BXT_REF_CLOCK_KHZ * pll_ratio) / 2;
>>  
>> -	/* Max possible output of clock is 39.5 MHz, program value -1 */
>> -	divider = (dsi_rate / BXT_MAX_VAR_OUTPUT_KHZ) - 1;
>> -	tmp |= BXT_MIPI_ESCLK_VAR_DIV(port, divider);
>> +	/*
>> +	 * tx clock should be <= 20MHz and the div value must be
>> +	 * subtracted by 1 as per bspec
>> +	 */
>> +	tx_div = DIV_ROUND_UP(dsi_rate, 20000) - 1;
>> +	/*
>> +	 * rx clock should be <= 150MHz and the div value must be
>> +	 * subtracted by 1 as per bspec
>> +	 */
>> +	rx_div = DIV_ROUND_UP(dsi_rate, 150000) - 1;
>>  
>>  	/*
>> -	 * Tx escape clock must be as close to 20MHz possible, but should
>> -	 * not exceed it. Hence select divide by 2
>> +	 * rx divider value needs to be updated in the
>> +	 * two differnt bit fields in the register hence splitting the
>> +	 * rx divider value accordingly
>>  	 */
>> -	tmp |= BXT_MIPI_TX_ESCLK_8XDIV_BY2(port);
>> +	rx_div_lower = rx_div & RX_DIVIDER_BIT_1_2;
>> +	rx_div_upper = (rx_div & RX_DIVIDER_BIT_3_4) >> 2;
>> +
>> +	/* As per bpsec program the 8/3X clock divider to the below value */
>> +	if (dev_priv->vbt.dsi.config->is_cmd_mode)
>> +		mipi_8by3_divider = 0x2;
>> +	else
>> +		mipi_8by3_divider = 0x3;
>>  
>> -	tmp |= BXT_MIPI_RX_ESCLK_8X_BY3(port);
>> +	tmp |= BXT_MIPI_8X_BY3_DIVIDER(port, mipi_8by3_divider);
>> +	tmp |= BXT_MIPI_TX_ESCLK_DIVIDER(port, tx_div);
>> +	tmp |= BXT_MIPI_RX_ESCLK_LOWER_DIVIDER(port, rx_div_lower);
>> +	tmp |= BXT_MIPI_RX_ESCLK_UPPER_DIVIDER(port, rx_div_upper);
>>  
>>  	I915_WRITE(BXT_MIPI_CLOCK_CTL, tmp);
>>  }
>> @@ -513,9 +535,9 @@ static void bxt_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
>>  	/* Clear old configurations */
>>  	tmp = I915_READ(BXT_MIPI_CLOCK_CTL);
>>  	tmp &= ~(BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port));
>> -	tmp &= ~(BXT_MIPI_RX_ESCLK_FIXDIV_MASK(port));
>> -	tmp &= ~(BXT_MIPI_ESCLK_VAR_DIV_MASK(port));
>> -	tmp &= ~(BXT_MIPI_DPHY_DIVIDER_MASK(port));
>> +	tmp &= ~(BXT_MIPI_RX_ESCLK_UPPER_FIXDIV_MASK(port));
>> +	tmp &= ~(BXT_MIPI_8X_BY3_DIVIDER_MASK(port));
>> +	tmp &= ~(BXT_MIPI_RX_ESCLK_LOWER_FIXDIV_MASK(port));
>>  	I915_WRITE(BXT_MIPI_CLOCK_CTL, tmp);
>>  	I915_WRITE(MIPI_EOT_DISABLE(port), CLOCKSTOP);
>>  }

-- 
Jani Nikula, Intel Open Source Technology Center


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