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linux-next/include/linux/amba/pl022.h
Chris Blair 14af60b6fb spi/pl022: Add high priority message pump support
This switches the PL022 worker to a kthread in order to get
hold of a mechanism to control the message pump priority. On
low-latency systems elevating the message kthread to realtime
priority give a real sleek response curve. This has been
confirmed by measurements. Realtime priority elevation for
a certain PL022 port can be requested from platform data.

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Chris Blair <chris.blair@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-02-02 11:32:16 -07:00

301 lines
9.0 KiB
C

/*
* include/linux/amba/pl022.h
*
* Copyright (C) 2008-2009 ST-Ericsson AB
* Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
*
* Author: Linus Walleij <linus.walleij@stericsson.com>
*
* Initial version inspired by:
* linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
* Initial adoption to PL022 by:
* Sachin Verma <sachin.verma@st.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _SSP_PL022_H
#define _SSP_PL022_H
#include <linux/device.h>
/**
* whether SSP is in loopback mode or not
*/
enum ssp_loopback {
LOOPBACK_DISABLED,
LOOPBACK_ENABLED
};
/**
* enum ssp_interface - interfaces allowed for this SSP Controller
* @SSP_INTERFACE_MOTOROLA_SPI: Motorola Interface
* @SSP_INTERFACE_TI_SYNC_SERIAL: Texas Instrument Synchronous Serial
* interface
* @SSP_INTERFACE_NATIONAL_MICROWIRE: National Semiconductor Microwire
* interface
* @SSP_INTERFACE_UNIDIRECTIONAL: Unidirectional interface (STn8810
* &STn8815 only)
*/
enum ssp_interface {
SSP_INTERFACE_MOTOROLA_SPI,
SSP_INTERFACE_TI_SYNC_SERIAL,
SSP_INTERFACE_NATIONAL_MICROWIRE,
SSP_INTERFACE_UNIDIRECTIONAL
};
/**
* enum ssp_hierarchy - whether SSP is configured as Master or Slave
*/
enum ssp_hierarchy {
SSP_MASTER,
SSP_SLAVE
};
/**
* enum ssp_clock_params - clock parameters, to set SSP clock at a
* desired freq
*/
struct ssp_clock_params {
u8 cpsdvsr; /* value from 2 to 254 (even only!) */
u8 scr; /* value from 0 to 255 */
};
/**
* enum ssp_rx_endian - endianess of Rx FIFO Data
* this feature is only available in ST versionf of PL022
*/
enum ssp_rx_endian {
SSP_RX_MSB,
SSP_RX_LSB
};
/**
* enum ssp_tx_endian - endianess of Tx FIFO Data
*/
enum ssp_tx_endian {
SSP_TX_MSB,
SSP_TX_LSB
};
/**
* enum ssp_data_size - number of bits in one data element
*/
enum ssp_data_size {
SSP_DATA_BITS_4 = 0x03, SSP_DATA_BITS_5, SSP_DATA_BITS_6,
SSP_DATA_BITS_7, SSP_DATA_BITS_8, SSP_DATA_BITS_9,
SSP_DATA_BITS_10, SSP_DATA_BITS_11, SSP_DATA_BITS_12,
SSP_DATA_BITS_13, SSP_DATA_BITS_14, SSP_DATA_BITS_15,
SSP_DATA_BITS_16, SSP_DATA_BITS_17, SSP_DATA_BITS_18,
SSP_DATA_BITS_19, SSP_DATA_BITS_20, SSP_DATA_BITS_21,
SSP_DATA_BITS_22, SSP_DATA_BITS_23, SSP_DATA_BITS_24,
SSP_DATA_BITS_25, SSP_DATA_BITS_26, SSP_DATA_BITS_27,
SSP_DATA_BITS_28, SSP_DATA_BITS_29, SSP_DATA_BITS_30,
SSP_DATA_BITS_31, SSP_DATA_BITS_32
};
/**
* enum ssp_mode - SSP mode of operation (Communication modes)
*/
enum ssp_mode {
INTERRUPT_TRANSFER,
POLLING_TRANSFER,
DMA_TRANSFER
};
/**
* enum ssp_rx_level_trig - receive FIFO watermark level which triggers
* IT: Interrupt fires when _N_ or more elements in RX FIFO.
*/
enum ssp_rx_level_trig {
SSP_RX_1_OR_MORE_ELEM,
SSP_RX_4_OR_MORE_ELEM,
SSP_RX_8_OR_MORE_ELEM,
SSP_RX_16_OR_MORE_ELEM,
SSP_RX_32_OR_MORE_ELEM
};
/**
* Transmit FIFO watermark level which triggers (IT Interrupt fires
* when _N_ or more empty locations in TX FIFO)
*/
enum ssp_tx_level_trig {
SSP_TX_1_OR_MORE_EMPTY_LOC,
SSP_TX_4_OR_MORE_EMPTY_LOC,
SSP_TX_8_OR_MORE_EMPTY_LOC,
SSP_TX_16_OR_MORE_EMPTY_LOC,
SSP_TX_32_OR_MORE_EMPTY_LOC
};
/**
* enum SPI Clock Phase - clock phase (Motorola SPI interface only)
* @SSP_CLK_FIRST_EDGE: Receive data on first edge transition (actual direction depends on polarity)
* @SSP_CLK_SECOND_EDGE: Receive data on second edge transition (actual direction depends on polarity)
*/
enum ssp_spi_clk_phase {
SSP_CLK_FIRST_EDGE,
SSP_CLK_SECOND_EDGE
};
/**
* enum SPI Clock Polarity - clock polarity (Motorola SPI interface only)
* @SSP_CLK_POL_IDLE_LOW: Low inactive level
* @SSP_CLK_POL_IDLE_HIGH: High inactive level
*/
enum ssp_spi_clk_pol {
SSP_CLK_POL_IDLE_LOW,
SSP_CLK_POL_IDLE_HIGH
};
/**
* Microwire Conrol Lengths Command size in microwire format
*/
enum ssp_microwire_ctrl_len {
SSP_BITS_4 = 0x03, SSP_BITS_5, SSP_BITS_6,
SSP_BITS_7, SSP_BITS_8, SSP_BITS_9,
SSP_BITS_10, SSP_BITS_11, SSP_BITS_12,
SSP_BITS_13, SSP_BITS_14, SSP_BITS_15,
SSP_BITS_16, SSP_BITS_17, SSP_BITS_18,
SSP_BITS_19, SSP_BITS_20, SSP_BITS_21,
SSP_BITS_22, SSP_BITS_23, SSP_BITS_24,
SSP_BITS_25, SSP_BITS_26, SSP_BITS_27,
SSP_BITS_28, SSP_BITS_29, SSP_BITS_30,
SSP_BITS_31, SSP_BITS_32
};
/**
* enum Microwire Wait State
* @SSP_MWIRE_WAIT_ZERO: No wait state inserted after last command bit
* @SSP_MWIRE_WAIT_ONE: One wait state inserted after last command bit
*/
enum ssp_microwire_wait_state {
SSP_MWIRE_WAIT_ZERO,
SSP_MWIRE_WAIT_ONE
};
/**
* enum ssp_duplex - whether Full/Half Duplex on microwire, only
* available in the ST Micro variant.
* @SSP_MICROWIRE_CHANNEL_FULL_DUPLEX: SSPTXD becomes bi-directional,
* SSPRXD not used
* @SSP_MICROWIRE_CHANNEL_HALF_DUPLEX: SSPTXD is an output, SSPRXD is
* an input.
*/
enum ssp_duplex {
SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
SSP_MICROWIRE_CHANNEL_HALF_DUPLEX
};
/**
* enum ssp_clkdelay - an optional clock delay on the feedback clock
* only available in the ST Micro PL023 variant.
* @SSP_FEEDBACK_CLK_DELAY_NONE: no delay, the data coming in from the
* slave is sampled directly
* @SSP_FEEDBACK_CLK_DELAY_1T: the incoming slave data is sampled with
* a delay of T-dt
* @SSP_FEEDBACK_CLK_DELAY_2T: dito with a delay if 2T-dt
* @SSP_FEEDBACK_CLK_DELAY_3T: dito with a delay if 3T-dt
* @SSP_FEEDBACK_CLK_DELAY_4T: dito with a delay if 4T-dt
* @SSP_FEEDBACK_CLK_DELAY_5T: dito with a delay if 5T-dt
* @SSP_FEEDBACK_CLK_DELAY_6T: dito with a delay if 6T-dt
* @SSP_FEEDBACK_CLK_DELAY_7T: dito with a delay if 7T-dt
*/
enum ssp_clkdelay {
SSP_FEEDBACK_CLK_DELAY_NONE,
SSP_FEEDBACK_CLK_DELAY_1T,
SSP_FEEDBACK_CLK_DELAY_2T,
SSP_FEEDBACK_CLK_DELAY_3T,
SSP_FEEDBACK_CLK_DELAY_4T,
SSP_FEEDBACK_CLK_DELAY_5T,
SSP_FEEDBACK_CLK_DELAY_6T,
SSP_FEEDBACK_CLK_DELAY_7T
};
/**
* CHIP select/deselect commands
*/
enum ssp_chip_select {
SSP_CHIP_SELECT,
SSP_CHIP_DESELECT
};
struct dma_chan;
/**
* struct pl022_ssp_master - device.platform_data for SPI controller devices.
* @num_chipselect: chipselects are used to distinguish individual
* SPI slaves, and are numbered from zero to num_chipselects - 1.
* each slave has a chipselect signal, but it's common that not
* every chipselect is connected to a slave.
* @enable_dma: if true enables DMA driven transfers.
* @dma_rx_param: parameter to locate an RX DMA channel.
* @dma_tx_param: parameter to locate a TX DMA channel.
* @autosuspend_delay: delay in ms following transfer completion before the
* runtime power management system suspends the device. A setting of 0
* indicates no delay and the device will be suspended immediately.
* @rt: indicates the controller should run the message pump with realtime
* priority to minimise the transfer latency on the bus.
*/
struct pl022_ssp_controller {
u16 bus_id;
u8 num_chipselect;
u8 enable_dma:1;
bool (*dma_filter)(struct dma_chan *chan, void *filter_param);
void *dma_rx_param;
void *dma_tx_param;
int autosuspend_delay;
bool rt;
};
/**
* struct ssp_config_chip - spi_board_info.controller_data for SPI
* slave devices, copied to spi_device.controller_data.
*
* @lbm: used for test purpose to internally connect RX and TX
* @iface: Interface type(Motorola, TI, Microwire, Universal)
* @hierarchy: sets whether interface is master or slave
* @slave_tx_disable: SSPTXD is disconnected (in slave mode only)
* @clk_freq: Tune freq parameters of SSP(when in master mode)
* @endian_rx: Endianess of Data in Rx FIFO
* @endian_tx: Endianess of Data in Tx FIFO
* @data_size: Width of data element(4 to 32 bits)
* @com_mode: communication mode: polling, Interrupt or DMA
* @rx_lev_trig: Rx FIFO watermark level (for IT & DMA mode)
* @tx_lev_trig: Tx FIFO watermark level (for IT & DMA mode)
* @clk_phase: Motorola SPI interface Clock phase
* @clk_pol: Motorola SPI interface Clock polarity
* @ctrl_len: Microwire interface: Control length
* @wait_state: Microwire interface: Wait state
* @duplex: Microwire interface: Full/Half duplex
* @clkdelay: on the PL023 variant, the delay in feeback clock cycles
* before sampling the incoming line
* @cs_control: function pointer to board-specific function to
* assert/deassert I/O port to control HW generation of devices chip-select.
* @dma_xfer_type: Type of DMA xfer (Mem-to-periph or Periph-to-Periph)
* @dma_config: DMA configuration for SSP controller and peripheral
*/
struct pl022_config_chip {
enum ssp_interface iface;
enum ssp_hierarchy hierarchy;
bool slave_tx_disable;
struct ssp_clock_params clk_freq;
enum ssp_mode com_mode;
enum ssp_rx_level_trig rx_lev_trig;
enum ssp_tx_level_trig tx_lev_trig;
enum ssp_microwire_ctrl_len ctrl_len;
enum ssp_microwire_wait_state wait_state;
enum ssp_duplex duplex;
enum ssp_clkdelay clkdelay;
void (*cs_control) (u32 control);
};
#endif /* _SSP_PL022_H */