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author | Sebastian Reichel <sre@kernel.org> | 2014-05-06 15:44:50 +0200 |
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committer | Sebastian Reichel <sre@kernel.org> | 2014-05-06 15:44:50 +0200 |
commit | 695f5ec02203ef23f127eacb86991d23307f3c6f (patch) | |
tree | ecb9c29268fa34559dfa06472d991bc5d92708be /Documentation | |
parent | 5bdeae302496a8ac49848f4fed26b1d87a67d966 (diff) | |
parent | 793ec5f7dccf95c0d6d5d57a925a13261a7cbd2b (diff) | |
download | linux-n900-dt-with-ssi.tar.bz2 |
Merge branch 'n900-modem-support' into n900-dt-with-ssin900-dt-with-ssi
Conflicts:
arch/arm/boot/dts/omap3-n900.dts
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/devicetree/bindings/hsi/client-devices.txt | 44 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/hsi/nokia-modem.txt | 57 | ||||
-rw-r--r-- | Documentation/devicetree/bindings/hsi/omap-ssi.txt | 97 | ||||
-rw-r--r-- | Documentation/hsi.txt | 75 |
4 files changed, 273 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/hsi/client-devices.txt b/Documentation/devicetree/bindings/hsi/client-devices.txt new file mode 100644 index 000000000000..104c9a3e57a4 --- /dev/null +++ b/Documentation/devicetree/bindings/hsi/client-devices.txt @@ -0,0 +1,44 @@ +Each HSI port is supposed to have one child node, which +symbols the remote device connected to the HSI port. The +following properties are standardized for HSI clients: + +Required HSI configuration properties: + +- hsi-channel-ids: A list of channel ids + +- hsi-rx-mode: Receiver Bit transmission mode ("stream" or "frame") +- hsi-tx-mode: Transmitter Bit transmission mode ("stream" or "frame") +- hsi-mode: May be used instead hsi-rx-mode and hsi-tx-mode if + the transmission mode is the same for receiver and + transmitter +- hsi-speed-kbps: Max bit transmission speed in kbit/s +- hsi-flow: RX flow type ("synchronized" or "pipeline") +- hsi-arb-mode: Arbitration mode for TX frame ("round-robin", "priority") + +Optional HSI configuration properties: + +- hsi-channel-names: A list with one name per channel specified in the + hsi-channel-ids property + + +Device Tree node example for an HSI client: + +hsi-controller { + hsi-port { + modem: hsi-client { + compatible = "nokia,n900-modem"; + + hsi-channel-ids = <0>, <1>, <2>, <3>; + hsi-channel-names = "mcsaab-control", + "speech-control", + "speech-data", + "mcsaab-data"; + hsi-speed-kbps = <55000>; + hsi-mode = "frame"; + hsi-flow = "synchronized"; + hsi-arb-mode = "round-robin"; + + /* more client specific properties */ + }; + }; +}; diff --git a/Documentation/devicetree/bindings/hsi/nokia-modem.txt b/Documentation/devicetree/bindings/hsi/nokia-modem.txt new file mode 100644 index 000000000000..8a979780452b --- /dev/null +++ b/Documentation/devicetree/bindings/hsi/nokia-modem.txt @@ -0,0 +1,57 @@ +Nokia modem client bindings + +The Nokia modem HSI client follows the common HSI client binding +and inherits all required properties. The following additional +properties are needed by the Nokia modem HSI client: + +Required properties: +- compatible: Should be one of + "nokia,n900-modem" +- hsi-channel-names: Should contain the following strings + "mcsaab-control" + "speech-control" + "speech-data" + "mcsaab-data" +- gpios: Should provide a GPIO handler for each GPIO listed in + gpio-names +- gpio-names: Should contain the following strings + "cmt_apeslpx" + "cmt_rst_rq" + "cmt_en" + "cmt_rst" + "cmt_bsi" +- interrupts: Should be IRQ handle for modem's reset indication + +Example: + +&ssi_port { + modem: hsi-client { + compatible = "nokia,n900-modem"; + + pinctrl-names = "default"; + pinctrl-0 = <&modem_pins>; + + hsi-channel-ids = <0>, <1>, <2>, <3>; + hsi-channel-names = "mcsaab-control", + "speech-control", + "speech-data", + "mcsaab-data"; + hsi-speed-kbps = <55000>; + hsi-mode = "frame"; + hsi-flow = "synchronized"; + hsi-arb-mode = "round-robin"; + + interrupts-extended = <&gpio3 8 IRQ_TYPE_EDGE_FALLING>; /* 72 */ + + gpios = <&gpio3 6 GPIO_ACTIVE_HIGH>, /* 70 */ + <&gpio3 9 GPIO_ACTIVE_HIGH>, /* 73 */ + <&gpio3 10 GPIO_ACTIVE_HIGH>, /* 74 */ + <&gpio3 11 GPIO_ACTIVE_HIGH>, /* 75 */ + <&gpio5 29 GPIO_ACTIVE_HIGH>; /* 157 */ + gpio-names = "cmt_apeslpx", + "cmt_rst_rq", + "cmt_en", + "cmt_rst", + "cmt_bsi"; + }; +}; diff --git a/Documentation/devicetree/bindings/hsi/omap-ssi.txt b/Documentation/devicetree/bindings/hsi/omap-ssi.txt new file mode 100644 index 000000000000..f26625e42693 --- /dev/null +++ b/Documentation/devicetree/bindings/hsi/omap-ssi.txt @@ -0,0 +1,97 @@ +OMAP SSI controller bindings + +OMAP Synchronous Serial Interface (SSI) controller implements a legacy +variant of MIPI's High Speed Synchronous Serial Interface (HSI). + +Required properties: +- compatible: Should include "ti,omap3-ssi". +- reg-names: Contains the values "sys" and "gdd" (in this order). +- reg: Contains a matching register specifier for each entry + in reg-names. +- interrupt-names: Contains the value "gdd_mpu". +- interrupts: Contains matching interrupt information for each entry + in interrupt-names. +- ranges: Represents the bus address mapping between the main + controller node and the child nodes below. +- clock-names: Must include the following entries: + "ssi_ssr_fck": The OMAP clock of that name + "ssi_sst_fck": The OMAP clock of that name + "ssi_ick": The OMAP clock of that name +- clocks: Contains a matching clock specifier for each entry in + clock-names. +- #address-cells: Should be set to <1> +- #size-cells: Should be set to <1> + +Each port is represented as a sub-node of the ti,omap3-ssi device. + +Required Port sub-node properties: +- compatible: Should be set to the following value + ti,omap3-ssi-port (applicable to OMAP34xx devices) +- reg-names: Contains the values "tx" and "rx" (in this order). +- reg: Contains a matching register specifier for each entry + in reg-names. +- interrupt-parent Should be a phandle for the interrupt controller +- interrupts: Should contain interrupt specifiers for mpu interrupts + 0 and 1 (in this order). +- ti,ssi-cawake-gpio: Defines which GPIO pin is used to signify CAWAKE + events for the port. This is an optional board-specific + property. If it's missing the port will not be + enabled. + +Example for Nokia N900: + +ssi-controller@48058000 { + compatible = "ti,omap3-ssi"; + + /* needed until hwmod is updated to use the compatible string */ + ti,hwmods = "ssi"; + + reg = <0x48058000 0x1000>, + <0x48059000 0x1000>; + reg-names = "sys", + "gdd"; + + interrupts = <55>; + interrupt-names = "gdd_mpu"; + + clocks = <&ssi_ssr_fck>, + <&ssi_sst_fck>, + <&ssi_ick>; + clock-names = "ssi_ssr_fck", + "ssi_sst_fck", + "ssi_ick"; + + #address-cells = <1>; + #size-cells = <1>; + ranges; + + ssi-port@4805a000 { + compatible = "ti,omap3-ssi-port"; + + reg = <0x4805a000 0x800>, + <0x4805a800 0x800>; + reg-names = "tx", + "rx"; + + interrupt-parent = <&intc>; + interrupts = <67>, + <68>; + + ti,ssi-cawake-gpio = <&gpio5 23 GPIO_ACTIVE_HIGH>; /* 151 */ + } + + ssi-port@4805a000 { + compatible = "ti,omap3-ssi-port"; + + reg = <0x4805b000 0x800>, + <0x4805b800 0x800>; + reg-names = "tx", + "rx"; + + interrupt-parent = <&intc>; + interrupts = <69>, + <70>; + + status = "disabled"; /* second port is not used on N900 */ + } +} diff --git a/Documentation/hsi.txt b/Documentation/hsi.txt new file mode 100644 index 000000000000..6ac6cd51852a --- /dev/null +++ b/Documentation/hsi.txt @@ -0,0 +1,75 @@ +HSI - High-speed Synchronous Serial Interface + +1. Introduction +~~~~~~~~~~~~~~~ + +High Speed Syncronous Interface (HSI) is a fullduplex, low latency protocol, +that is optimized for die-level interconnect between an Application Processor +and a Baseband chipset. It has been specified by the MIPI alliance in 2003 and +implemented by multiple vendors since then. + +The HSI interface supports full duplex communication over multiple channels +(typically 8) and is capable of reaching speeds up to 200 Mbit/s. + +The serial protocol uses two signals, DATA and FLAG as combined data and clock +signals and an additional READY signal for flow control. An additional WAKE +signal can be used to wakeup the chips from standby modes. The signals are +commonly prefixed by AC for signals going from the application die to the +cellular die and CA for signals going the other way around. + ++------------+ +---------------+ +| Cellular | | Application | +| Die | | Die | +| | - - - - - - CAWAKE - - - - - - >| | +| T|------------ CADATA ------------>|R | +| X|------------ CAFLAG ------------>|X | +| |<----------- ACREADY ------------| | +| | | | +| | | | +| |< - - - - - ACWAKE - - - - - - -| | +| R|<----------- ACDATA -------------|T | +| X|<----------- ACFLAG -------------|X | +| |------------ CAREADY ----------->| | +| | | | +| | | | ++------------+ +---------------+ + +2. HSI Subsystem in Linux +~~~~~~~~~~~~~~~~~~~~~~~~~ + +In the Linux kernel the hsi subsystem is supposed to be used for HSI devices. +The hsi subsystem contains drivers for hsi controllers including support for +multi-port controllers and provides a generic API for using the HSI ports. + +It also contains HSI client drivers, which make use of the generic API to +implement a protocol used on the HSI interface. These client drivers can +use an arbitrary number of channels. + +3. hsi-char Device +~~~~~~~~~~~~~~~~~~ + +Each port automatically registers a generic client driver called hsi_char, +which provides a charecter device for userspace representing the HSI port. +It can be used to communicate via HSI from userspace. Userspace may +configure the hsi_char device using the following ioctl commands: + +* HSC_RESET: + - flush the HSI port + +* HSC_SET_PM + - enable or disable the client. + +* HSC_SEND_BREAK + - send break + +* HSC_SET_RX + - set RX configuration + +* HSC_GET_RX + - get RX configuration + +* HSC_SET_TX + - set TX configuration + +* HSC_GET_TX + - get TX configuration |