diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/laptops/thinkpad-acpi.rst | 12 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml | 5 | ||||
| -rw-r--r-- | Documentation/i2c/smbus-protocol.rst | 14 | ||||
| -rw-r--r-- | Documentation/power/energy-model.rst | 53 |
4 files changed, 55 insertions, 29 deletions
diff --git a/Documentation/admin-guide/laptops/thinkpad-acpi.rst b/Documentation/admin-guide/laptops/thinkpad-acpi.rst index 6721a80a2d4f..475eb0e81e4a 100644 --- a/Documentation/admin-guide/laptops/thinkpad-acpi.rst +++ b/Documentation/admin-guide/laptops/thinkpad-acpi.rst @@ -1520,15 +1520,15 @@ This sysfs attribute controls the keyboard "face" that will be shown on the Lenovo X1 Carbon 2nd gen (2014)'s adaptive keyboard. The value can be read and set. -- 1 = Home mode -- 2 = Web-browser mode -- 3 = Web-conference mode -- 4 = Function mode -- 5 = Layflat mode +- 0 = Home mode +- 1 = Web-browser mode +- 2 = Web-conference mode +- 3 = Function mode +- 4 = Layflat mode For more details about which buttons will appear depending on the mode, please review the laptop's user guide: -http://www.lenovo.com/shop/americas/content/user_guides/x1carbon_2_ug_en.pdf +https://download.lenovo.com/ibmdl/pub/pc/pccbbs/mobiles_pdf/x1carbon_2_ug_en.pdf Battery charge control ---------------------- diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml index 29b9447f3b84..fe0c89edf7c1 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml +++ b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.yaml @@ -17,9 +17,10 @@ properties: oneOf: - enum: - fsl,imx7ulp-lpi2c - - fsl,imx8qm-lpi2c - items: - - const: fsl,imx8qxp-lpi2c + - enum: + - fsl,imx8qxp-lpi2c + - fsl,imx8qm-lpi2c - const: fsl,imx7ulp-lpi2c reg: diff --git a/Documentation/i2c/smbus-protocol.rst b/Documentation/i2c/smbus-protocol.rst index 9e07e6bbe6a3..00d8e17d0aca 100644 --- a/Documentation/i2c/smbus-protocol.rst +++ b/Documentation/i2c/smbus-protocol.rst @@ -36,6 +36,8 @@ Key to symbols =============== ============================================================= S Start condition +Sr Repeated start condition, used to switch from write to + read mode. P Stop condition Rd/Wr (1 bit) Read/Write bit. Rd equals 1, Wr equals 0. A, NA (1 bit) Acknowledge (ACK) and Not Acknowledge (NACK) bit @@ -100,7 +102,7 @@ Implemented by i2c_smbus_read_byte_data() This reads a single byte from a device, from a designated register. The register is specified through the Comm byte:: - S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] NA P + S Addr Wr [A] Comm [A] Sr Addr Rd [A] [Data] NA P Functionality flag: I2C_FUNC_SMBUS_READ_BYTE_DATA @@ -114,7 +116,7 @@ This operation is very like Read Byte; again, data is read from a device, from a designated register that is specified through the Comm byte. But this time, the data is a complete word (16 bits):: - S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P + S Addr Wr [A] Comm [A] Sr Addr Rd [A] [DataLow] A [DataHigh] NA P Functionality flag: I2C_FUNC_SMBUS_READ_WORD_DATA @@ -164,7 +166,7 @@ This command selects a device register (through the Comm byte), sends 16 bits of data to it, and reads 16 bits of data in return:: S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] - S Addr Rd [A] [DataLow] A [DataHigh] NA P + Sr Addr Rd [A] [DataLow] A [DataHigh] NA P Functionality flag: I2C_FUNC_SMBUS_PROC_CALL @@ -181,7 +183,7 @@ of data is specified by the device in the Count byte. :: S Addr Wr [A] Comm [A] - S Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P + Sr Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P Functionality flag: I2C_FUNC_SMBUS_READ_BLOCK_DATA @@ -212,7 +214,7 @@ This command selects a device register (through the Comm byte), sends 1 to 31 bytes of data to it, and reads 1 to 31 bytes of data in return:: S Addr Wr [A] Comm [A] Count [A] Data [A] ... - S Addr Rd [A] [Count] A [Data] ... A P + Sr Addr Rd [A] [Count] A [Data] ... A P Functionality flag: I2C_FUNC_SMBUS_BLOCK_PROC_CALL @@ -300,7 +302,7 @@ This command reads a block of bytes from a device, from a designated register that is specified through the Comm byte:: S Addr Wr [A] Comm [A] - S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P + Sr Addr Rd [A] [Data] A [Data] A ... A [Data] NA P Functionality flag: I2C_FUNC_SMBUS_READ_I2C_BLOCK diff --git a/Documentation/power/energy-model.rst b/Documentation/power/energy-model.rst index 8a2788afe89b..5ac62a7b4b7c 100644 --- a/Documentation/power/energy-model.rst +++ b/Documentation/power/energy-model.rst @@ -84,6 +84,16 @@ CONFIG_ENERGY_MODEL must be enabled to use the EM framework. 2.2 Registration of performance domains ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +Registration of 'advanced' EM +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The 'advanced' EM gets it's name due to the fact that the driver is allowed +to provide more precised power model. It's not limited to some implemented math +formula in the framework (like it's in 'simple' EM case). It can better reflect +the real power measurements performed for each performance state. Thus, this +registration method should be preferred in case considering EM static power +(leakage) is important. + Drivers are expected to register performance domains into the EM framework by calling the following API:: @@ -103,6 +113,18 @@ to: return warning/error, stop working or panic. See Section 3. for an example of driver implementing this callback, or Section 2.4 for further documentation on this API +Registration of 'simple' EM +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The 'simple' EM is registered using the framework helper function +cpufreq_register_em_with_opp(). It implements a power model which is tight to +math formula:: + + Power = C * V^2 * f + +The EM which is registered using this method might not reflect correctly the +physics of a real device, e.g. when static power (leakage) is important. + 2.3 Accessing performance domains ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -138,6 +160,10 @@ or in Section 2.4 3. Example driver ----------------- +The CPUFreq framework supports dedicated callback for registering +the EM for a given CPU(s) 'policy' object: cpufreq_driver::register_em(). +That callback has to be implemented properly for a given driver, +because the framework would call it at the right time during setup. This section provides a simple example of a CPUFreq driver registering a performance domain in the Energy Model framework using the (fake) 'foo' protocol. The driver implements an est_power() function to be provided to the @@ -167,25 +193,22 @@ EM framework:: 20 return 0; 21 } 22 - 23 static int foo_cpufreq_init(struct cpufreq_policy *policy) + 23 static void foo_cpufreq_register_em(struct cpufreq_policy *policy) 24 { 25 struct em_data_callback em_cb = EM_DATA_CB(est_power); 26 struct device *cpu_dev; - 27 int nr_opp, ret; + 27 int nr_opp; 28 29 cpu_dev = get_cpu_device(cpumask_first(policy->cpus)); 30 - 31 /* Do the actual CPUFreq init work ... */ - 32 ret = do_foo_cpufreq_init(policy); - 33 if (ret) - 34 return ret; - 35 - 36 /* Find the number of OPPs for this policy */ - 37 nr_opp = foo_get_nr_opp(policy); + 31 /* Find the number of OPPs for this policy */ + 32 nr_opp = foo_get_nr_opp(policy); + 33 + 34 /* And register the new performance domain */ + 35 em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, policy->cpus, + 36 true); + 37 } 38 - 39 /* And register the new performance domain */ - 40 em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, policy->cpus, - 41 true); - 42 - 43 return 0; - 44 } + 39 static struct cpufreq_driver foo_cpufreq_driver = { + 40 .register_em = foo_cpufreq_register_em, + 41 }; |