[ARM] 5546/1: ARM PL022 SSP/SPI driver v3

This adds a driver for the ARM PL022 PrimeCell SSP/SPI
driver found in the U300 platforms as well as in some
ARM reference hardware, and in a modified version on the
Nomadik board.
Reviewed-by: Alessandro Rubini <rubini-list@gnudd.com>
Reviewed-by: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/spi/Kconfig

@@ -171,6 +171,15 @@ config SPI_ORION
 	help
 	  This enables using the SPI master controller on the Orion chips.
 
+config SPI_PL022
+	tristate "ARM AMBA PL022 SSP controller (EXPERIMENTAL)"
+	depends on ARM_AMBA && EXPERIMENTAL
+	default y if MACH_U300
+	help
+	  This selects the ARM(R) AMBA(R) PrimeCell PL022 SSP
+	  controller. If you have an embedded system with an AMBA(R)
+	  bus and a PL022 controller, say Y or M here.
+
 config SPI_PXA2XX
 	tristate "PXA2xx SSP SPI master"
 	depends on ARCH_PXA && EXPERIMENTAL

drivers/spi/Makefile

@@ -23,6 +23,7 @@ obj-$(CONFIG_SPI_PXA2XX)		+= pxa2xx_spi.o
 obj-$(CONFIG_SPI_OMAP_UWIRE)		+= omap_uwire.o
 obj-$(CONFIG_SPI_OMAP24XX)		+= omap2_mcspi.o
 obj-$(CONFIG_SPI_ORION)			+= orion_spi.o
+obj-$(CONFIG_SPI_PL022)			+= amba-pl022.o
 obj-$(CONFIG_SPI_MPC52xx_PSC)		+= mpc52xx_psc_spi.o
 obj-$(CONFIG_SPI_MPC83xx)		+= spi_mpc83xx.o
 obj-$(CONFIG_SPI_S3C24XX_GPIO)		+= spi_s3c24xx_gpio.o

include/linux/amba/pl022.h

+/*
+ * 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
+ */
+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_RISING_EDGE: Receive data on rising edge
+ * @SSP_CLK_FALLING_EDGE: Receive data on falling edge
+ */
+enum ssp_spi_clk_phase {
+	SSP_CLK_RISING_EDGE,
+	SSP_CLK_FALLING_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 Microwire - whether Full/Half Duplex
+ * @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
+};
+
+/**
+ * CHIP select/deselect commands
+ */
+enum ssp_chip_select {
+	SSP_CHIP_SELECT,
+	SSP_CHIP_DESELECT
+};
+
+
+/**
+ * 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.
+ */
+struct pl022_ssp_controller {
+	u16 bus_id;
+	u8 num_chipselect;
+	u8 enable_dma:1;
+};
+
+/**
+ * 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
+ * @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 {
+	struct device *dev;
+	enum ssp_loopback lbm;
+	enum ssp_interface iface;
+	enum ssp_hierarchy hierarchy;
+	bool slave_tx_disable;
+	struct ssp_clock_params clk_freq;
+	enum ssp_rx_endian endian_rx;
+	enum ssp_tx_endian endian_tx;
+	enum ssp_data_size data_size;
+	enum ssp_mode com_mode;
+	enum ssp_rx_level_trig rx_lev_trig;
+	enum ssp_tx_level_trig tx_lev_trig;
+	enum ssp_spi_clk_phase clk_phase;
+	enum ssp_spi_clk_pol clk_pol;
+	enum ssp_microwire_ctrl_len ctrl_len;
+	enum ssp_microwire_wait_state wait_state;
+	enum ssp_duplex duplex;
+	void (*cs_control) (u32 control);
+};
+
+#endif /* _SSP_PL022_H */