Commit 36426411 authored by Alex Elder's avatar Alex Elder Committed by Jakub Kicinski
Browse files

net: ipa: set up IPA v4.5 Qtime configuration 



IPA v4.5 introduces a new unified timer architecture driven on the
19.2 MHz SoC crystal oscillator (XO).  It is independent of the IPA
core clock and avoids some duplication.

Lower-resolution time stamps are derived from this by using only the
high-order bits of the 19.2 MHz Qtime clock.  And timers are derived
from this based on "pulse generators" configured to fire at a fixed
rate based on the Qtime clock.

This patch introduces ipa_qtime_config(), which configures the Qtime
mechanism for use.  It also adds to the IPA register definitions
related to timers and time stamping.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6bf754c7

drivers/net/ipa/ipa_main.c

+63 −4
Original line number Diff line number Diff line
@@ -70,6 +70,14 @@ 
#define IPA_FWS_PATH		"ipa_fws.mdt"

#define IPA_PAS_ID		15



/* Shift of 19.2 MHz timestamp to achieve lower resolution timestamps */

#define DPL_TIMESTAMP_SHIFT	14	/* ~1.172 kHz, ~853 usec per tick */

#define TAG_TIMESTAMP_SHIFT	14

#define NAT_TIMESTAMP_SHIFT	24	/* ~1.144 Hz, ~874 msec per tick */



/* Divider for 19.2 MHz crystal oscillator clock to get common timer clock */

#define IPA_XO_CLOCK_DIVIDER	192	/* 1 is subtracted where used */



/**

 * ipa_suspend_handler() - Handle the suspend IPA interrupt

 * @ipa:	IPA pointer
@@ -292,6 +300,53 @@ static void ipa_hardware_config_qsb(struct ipa *ipa) 
	iowrite32(val, ipa->reg_virt + IPA_REG_QSB_MAX_READS_OFFSET);

}



/* IPA uses unified Qtime starting at IPA v4.5, implementing various

 * timestamps and timers independent of the IPA core clock rate.  The

 * Qtimer is based on a 56-bit timestamp incremented at each tick of

 * a 19.2 MHz SoC crystal oscillator (XO clock).

 *

 * For IPA timestamps (tag, NAT, data path logging) a lower resolution

 * timestamp is achieved by shifting the Qtimer timestamp value right

 * some number of bits to produce the low-order bits of the coarser

 * granularity timestamp.

 *

 * For timers, a common timer clock is derived from the XO clock using

 * a divider (we use 192, to produce a 100kHz timer clock).  From

 * this common clock, three "pulse generators" are used to produce

 * timer ticks at a configurable frequency.  IPA timers (such as

 * those used for aggregation or head-of-line block handling) now

 * define their period based on one of these pulse generators.

 */

static void ipa_qtime_config(struct ipa *ipa)

{

	u32 val;



	/* Timer clock divider must be disabled when we change the rate */

	iowrite32(0, ipa->reg_virt + IPA_REG_TIMERS_XO_CLK_DIV_CFG_OFFSET);



	/* Set DPL time stamp resolution to use Qtime (instead of 1 msec) */

	val = u32_encode_bits(DPL_TIMESTAMP_SHIFT, DPL_TIMESTAMP_LSB_FMASK);

	val |= u32_encode_bits(1, DPL_TIMESTAMP_SEL_FMASK);

	/* Configure tag and NAT Qtime timestamp resolution as well */

	val |= u32_encode_bits(TAG_TIMESTAMP_SHIFT, TAG_TIMESTAMP_LSB_FMASK);

	val |= u32_encode_bits(NAT_TIMESTAMP_SHIFT, NAT_TIMESTAMP_LSB_FMASK);

	iowrite32(val, ipa->reg_virt + IPA_REG_QTIME_TIMESTAMP_CFG_OFFSET);



	/* Set granularity of pulse generators used for other timers */

	val = u32_encode_bits(IPA_GRAN_100_US, GRAN_0_FMASK);

	val |= u32_encode_bits(IPA_GRAN_1_MS, GRAN_1_FMASK);

	val |= u32_encode_bits(IPA_GRAN_1_MS, GRAN_2_FMASK);

	iowrite32(val, ipa->reg_virt + IPA_REG_TIMERS_PULSE_GRAN_CFG_OFFSET);



	/* Actual divider is 1 more than value supplied here */

	val = u32_encode_bits(IPA_XO_CLOCK_DIVIDER - 1, DIV_VALUE_FMASK);

	iowrite32(val, ipa->reg_virt + IPA_REG_TIMERS_XO_CLK_DIV_CFG_OFFSET);



	/* Divider value is set; re-enable the common timer clock divider */

	val |= u32_encode_bits(1, DIV_ENABLE_FMASK);

	iowrite32(val, ipa->reg_virt + IPA_REG_TIMERS_XO_CLK_DIV_CFG_OFFSET);

}



static void ipa_idle_indication_cfg(struct ipa *ipa,

				    u32 enter_idle_debounce_thresh,

				    bool const_non_idle_enable)
@@ -362,10 +417,14 @@ static void ipa_hardware_config(struct ipa *ipa) 
	/* Configure system bus limits */

	ipa_hardware_config_qsb(ipa);



	/* Configure aggregation granularity */

	if (version < IPA_VERSION_4_5) {

		/* Configure aggregation timer granularity */

		granularity = ipa_aggr_granularity_val(IPA_AGGR_GRANULARITY);

		val = u32_encode_bits(granularity, AGGR_GRANULARITY_FMASK);

		iowrite32(val, ipa->reg_virt + IPA_REG_COUNTER_CFG_OFFSET);

	} else {

		ipa_qtime_config(ipa);

	}



	/* IPA v4.2 does not support hashed tables, so disable them */

	if (version == IPA_VERSION_4_2) {

drivers/net/ipa/ipa_reg.h

+30 −0
Original line number Diff line number Diff line
@@ -223,6 +223,7 @@ static inline u32 ipa_reg_bcr_val(enum ipa_version version) 
/* ipa->available defines the valid bits in the AGGR_FORCE_CLOSE register */

#define IPA_REG_AGGR_FORCE_CLOSE_OFFSET			0x000001ec



/* The next register is not present for IPA v4.5 */

#define IPA_REG_COUNTER_CFG_OFFSET			0x000001f0

#define AGGR_GRANULARITY_FMASK			GENMASK(8, 4)
@@ -274,6 +275,35 @@ static inline u32 ipa_reg_idle_indication_cfg_offset(enum ipa_version version) 
#define ENTER_IDLE_DEBOUNCE_THRESH_FMASK	GENMASK(15, 0)

#define CONST_NON_IDLE_ENABLE_FMASK		GENMASK(16, 16)



/* The next register is present for IPA v4.5 */

#define IPA_REG_QTIME_TIMESTAMP_CFG_OFFSET		0x0000024c

#define DPL_TIMESTAMP_LSB_FMASK			GENMASK(4, 0)

#define DPL_TIMESTAMP_SEL_FMASK			GENMASK(7, 7)

#define TAG_TIMESTAMP_LSB_FMASK			GENMASK(12, 8)

#define NAT_TIMESTAMP_LSB_FMASK			GENMASK(20, 16)



/* The next register is present for IPA v4.5 */

#define IPA_REG_TIMERS_XO_CLK_DIV_CFG_OFFSET		0x00000250

#define DIV_VALUE_FMASK				GENMASK(8, 0)

#define DIV_ENABLE_FMASK			GENMASK(31, 31)



/* The next register is present for IPA v4.5 */

#define IPA_REG_TIMERS_PULSE_GRAN_CFG_OFFSET		0x00000254

#define GRAN_0_FMASK				GENMASK(2, 0)

#define GRAN_1_FMASK				GENMASK(5, 3)

#define GRAN_2_FMASK				GENMASK(8, 6)

/* Values for GRAN_x fields of TIMERS_PULSE_GRAN_CFG */

enum ipa_pulse_gran {

	IPA_GRAN_10_US				= 0x0,

	IPA_GRAN_20_US				= 0x1,

	IPA_GRAN_50_US				= 0x2,

	IPA_GRAN_100_US				= 0x3,

	IPA_GRAN_1_MS				= 0x4,

	IPA_GRAN_10_MS				= 0x5,

	IPA_GRAN_100_MS				= 0x6,

	IPA_GRAN_655350_US			= 0x7,

};



/* # IPA source resource groups available based on version */

static inline u32 ipa_resource_group_src_count(enum ipa_version version)

{

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