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| author | Hans de Goede <hdegoede@redhat.com> | 2021-07-06 18:09:23 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-07-16 19:05:59 +0200 |
| commit | fd080a01ecfc92984cabca6e54c61fe0f70e3984 (patch) | |
| tree | 50d54b8e7788d7156806a92e3fd0df732e9d8645 /drivers/acpi | |
| parent | e38ba404f20c4beb1a5d4547567d2934a5b95843 (diff) | |
| download | linux-fd080a01ecfc92984cabca6e54c61fe0f70e3984.tar.bz2 | |
ACPI / PMIC: XPower: optimize MIPI PMIQ sequence I2C-bus accesses
The I2C-bus to the XPower AXP288 is shared between the Linux kernel and
the SoCs P-Unit. The P-Unit has a semaphore which the kernel must "lock"
before it may use the bus and while the kernel holds the semaphore the CPU
and GPU power-states must not be changed otherwise the system will freeze.
This is a complex process, which is quite expensive. This is all done by
iosf_mbi_block_punit_i2c_access(). To ensure that no unguarded I2C-bus
accesses happen, iosf_mbi_block_punit_i2c_access() gets called by the
I2C-bus-driver for every I2C transfer. Because this is so expensive it
is allowed to call iosf_mbi_block_punit_i2c_access() in a nested
fashion, so that higher-level code which does multiple I2C-transfers can
call it once for a group of transfers, turning the calls done by the
I2C-bus-driver into no-ops.
The default exec_mipi_pmic_seq_element implementation from
drivers/acpi/pmic/intel_pmic.c does a regmap_update_bits() call and
the involved registers are typically marked as volatile in the regmap,
so this leads to 2 I2C-bus accesses.
Add a XPower AXP288 specific implementation of exec_mipi_pmic_seq_element
which calls iosf_mbi_block_punit_i2c_access() calls before the
regmap_update_bits() call to avoid having to do the whole expensive
acquire P-Unit semaphore dance twice.
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/pmic/intel_pmic_xpower.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/acpi/pmic/intel_pmic_xpower.c b/drivers/acpi/pmic/intel_pmic_xpower.c index 5750c5e7d4c6..cbe08e600fa3 100644 --- a/drivers/acpi/pmic/intel_pmic_xpower.c +++ b/drivers/acpi/pmic/intel_pmic_xpower.c @@ -270,10 +270,34 @@ static int intel_xpower_pmic_get_raw_temp(struct regmap *regmap, int reg) return ret; } +static int intel_xpower_exec_mipi_pmic_seq_element(struct regmap *regmap, + u16 i2c_address, u32 reg_address, + u32 value, u32 mask) +{ + int ret; + + if (i2c_address != 0x34) { + pr_err("%s: Unexpected i2c-addr: 0x%02x (reg-addr 0x%x value 0x%x mask 0x%x)\n", + __func__, i2c_address, reg_address, value, mask); + return -ENXIO; + } + + ret = iosf_mbi_block_punit_i2c_access(); + if (ret) + return ret; + + ret = regmap_update_bits(regmap, reg_address, mask, value); + + iosf_mbi_unblock_punit_i2c_access(); + + return ret; +} + static struct intel_pmic_opregion_data intel_xpower_pmic_opregion_data = { .get_power = intel_xpower_pmic_get_power, .update_power = intel_xpower_pmic_update_power, .get_raw_temp = intel_xpower_pmic_get_raw_temp, + .exec_mipi_pmic_seq_element = intel_xpower_exec_mipi_pmic_seq_element, .power_table = power_table, .power_table_count = ARRAY_SIZE(power_table), .thermal_table = thermal_table, |