text: /*
   * This file is part of wl1271
   *
   * Copyright (C) 2008-2009 Nokia Corporation
   *
   * Contact: Luciano Coelho <luciano.coelho@nokia.com>
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * version 2 as published by the Free Software Foundation.
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
   * 02110-1301 USA
   *
   */
  
  #include <linux/interrupt.h>
  #include <linux/irq.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/swab.h>
  #include <linux/crc7.h>
  #include <linux/spi/spi.h>
  #include <linux/wl12xx.h>
  #include <linux/platform_device.h>
  
  #include "wlcore.h"
  #include "wl12xx_80211.h"
  #include "io.h"
  
  #define WSPI_CMD_READ                 0x40000000
  #define WSPI_CMD_WRITE                0x00000000
  #define WSPI_CMD_FIXED                0x20000000
  #define WSPI_CMD_BYTE_LENGTH          0x1FFE0000
  #define WSPI_CMD_BYTE_LENGTH_OFFSET   17
  #define WSPI_CMD_BYTE_ADDR            0x0001FFFF
  
  #define WSPI_INIT_CMD_CRC_LEN       5
  
  #define WSPI_INIT_CMD_START         0x00
  #define WSPI_INIT_CMD_TX            0x40
  /* the extra bypass bit is sampled by the TNET as '1' */
  #define WSPI_INIT_CMD_BYPASS_BIT    0x80
  #define WSPI_INIT_CMD_FIXEDBUSY_LEN 0x07
  #define WSPI_INIT_CMD_EN_FIXEDBUSY  0x80
  #define WSPI_INIT_CMD_DIS_FIXEDBUSY 0x00
  #define WSPI_INIT_CMD_IOD           0x40
  #define WSPI_INIT_CMD_IP            0x20
  #define WSPI_INIT_CMD_CS            0x10
  #define WSPI_INIT_CMD_WS            0x08
  #define WSPI_INIT_CMD_WSPI          0x01
  #define WSPI_INIT_CMD_END           0x01
  
  #define WSPI_INIT_CMD_LEN           8
  
  #define HW_ACCESS_WSPI_FIXED_BUSY_LEN \
  		((WL1271_BUSY_WORD_LEN - 4) / sizeof(u32))
  #define HW_ACCESS_WSPI_INIT_CMD_MASK  0
  
  /* HW limitation: maximum possible chunk size is 4095 bytes */
  #define WSPI_MAX_CHUNK_SIZE    4092
  
  /*
   * only support SPI for 12xx - this code should be reworked when 18xx
   * support is introduced
   */
  #define SPI_AGGR_BUFFER_SIZE (4 * PAGE_SIZE)
  
  /* Maximum number of SPI write chunks */
  #define WSPI_MAX_NUM_OF_CHUNKS \
  	((SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE) + 1)
  
  
  struct wl12xx_spi_glue {
  	struct device *dev;
  	struct platform_device *core;
  };
  
  static void wl12xx_spi_reset(struct device *child)
  {
  	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
  	u8 *cmd;
  	struct spi_transfer t;
  	struct spi_message m;
  
  	cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
  	if (!cmd) {
  		dev_err(child->parent,
  			"could not allocate cmd for spi reset\n");
  		return;
  	}
  
  	memset(&t, 0, sizeof(t));
  	spi_message_init(&m);
  
  	memset(cmd, 0xff, WSPI_INIT_CMD_LEN);
  
  	t.tx_buf = cmd;
  	t.len = WSPI_INIT_CMD_LEN;
  	spi_message_add_tail(&t, &m);
  
  	spi_sync(to_spi_device(glue->dev), &m);
  
  	kfree(cmd);
  }
  
  static void wl12xx_spi_init(struct device *child)
  {
  	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
  	struct spi_transfer t;
  	struct spi_message m;
  	u8 *cmd = kzalloc(WSPI_INIT_CMD_LEN, GFP_KERNEL);
  
  	if (!cmd) {
  		dev_err(child->parent,
  			"could not allocate cmd for spi init\n");
  		return;
  	}
  
  	memset(&t, 0, sizeof(t));
  	spi_message_init(&m);
  
  	/*
  	 * Set WSPI_INIT_COMMAND
  	 * the data is being send from the MSB to LSB
  	 */
  	cmd[0] = 0xff;
  	cmd[1] = 0xff;
  	cmd[2] = WSPI_INIT_CMD_START | WSPI_INIT_CMD_TX;
  	cmd[3] = 0;
  	cmd[4] = 0;
  	cmd[5] = HW_ACCESS_WSPI_INIT_CMD_MASK << 3;
  	cmd[5] |= HW_ACCESS_WSPI_FIXED_BUSY_LEN & WSPI_INIT_CMD_FIXEDBUSY_LEN;
  
  	cmd[6] = WSPI_INIT_CMD_IOD | WSPI_INIT_CMD_IP | WSPI_INIT_CMD_CS
  		| WSPI_INIT_CMD_WSPI | WSPI_INIT_CMD_WS;
  
  	if (HW_ACCESS_WSPI_FIXED_BUSY_LEN == 0)
  		cmd[6] |= WSPI_INIT_CMD_DIS_FIXEDBUSY;
  	else
  		cmd[6] |= WSPI_INIT_CMD_EN_FIXEDBUSY;
  
  	cmd[7] = crc7_be(0, cmd+2, WSPI_INIT_CMD_CRC_LEN) | WSPI_INIT_CMD_END;
  	/*
  	 * The above is the logical order; it must actually be stored
  	 * in the buffer byte-swapped.
  	 */
  	__swab32s((u32 *)cmd);
  	__swab32s((u32 *)cmd+1);
  
  	t.tx_buf = cmd;
  	t.len = WSPI_INIT_CMD_LEN;
  	spi_message_add_tail(&t, &m);
  
  	spi_sync(to_spi_device(glue->dev), &m);
  	kfree(cmd);
  }
  
  #define WL1271_BUSY_WORD_TIMEOUT 1000
  
  static int wl12xx_spi_read_busy(struct device *child)
  {
  	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
  	struct wl1271 *wl = dev_get_drvdata(child);
  	struct spi_transfer t[1];
  	struct spi_message m;
  	u32 *busy_buf;
  	int num_busy_bytes = 0;
  
  	/*
  	 * Read further busy words from SPI until a non-busy word is
  	 * encountered, then read the data itself into the buffer.
  	 */
  
  	num_busy_bytes = WL1271_BUSY_WORD_TIMEOUT;
  	busy_buf = wl->buffer_busyword;
  	while (num_busy_bytes) {
  		num_busy_bytes--;
  		spi_message_init(&m);
  		memset(t, 0, sizeof(t));
  		t[0].rx_buf = busy_buf;
  		t[0].len = sizeof(u32);
  		t[0].cs_change = true;
  		spi_message_add_tail(&t[0], &m);
  		spi_sync(to_spi_device(glue->dev), &m);
  
  		if (*busy_buf & 0x1)
  			return 0;
  	}
  
  	/* The SPI bus is unresponsive, the read failed. */
  	dev_err(child->parent, "SPI read busy-word timeout!\n");
  	return -ETIMEDOUT;
  }
  
  static int __must_check wl12xx_spi_raw_read(struct device *child, int addr,
  					    void *buf, size_t len, bool fixed)
  {
  	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
  	struct wl1271 *wl = dev_get_drvdata(child);
  	struct spi_transfer t[2];
  	struct spi_message m;
  	u32 *busy_buf;
  	u32 *cmd;
  	u32 chunk_len;
  
  	while (len > 0) {
  		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
  
  		cmd = &wl->buffer_cmd;
  		busy_buf = wl->buffer_busyword;
  
  		*cmd = 0;
  		*cmd |= WSPI_CMD_READ;
  		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
  			WSPI_CMD_BYTE_LENGTH;
  		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
  
  		if (fixed)
  			*cmd |= WSPI_CMD_FIXED;
  
  		spi_message_init(&m);
  		memset(t, 0, sizeof(t));
  
  		t[0].tx_buf = cmd;
  		t[0].len = 4;
  		t[0].cs_change = true;
  		spi_message_add_tail(&t[0], &m);
  
  		/* Busy and non busy words read */
  		t[1].rx_buf = busy_buf;
  		t[1].len = WL1271_BUSY_WORD_LEN;
  		t[1].cs_change = true;
  		spi_message_add_tail(&t[1], &m);
  
  		spi_sync(to_spi_device(glue->dev), &m);
  
  		if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
  		    wl12xx_spi_read_busy(child)) {
  			memset(buf, 0, chunk_len);
  			return 0;
  		}
  
  		spi_message_init(&m);
  		memset(t, 0, sizeof(t));
  
  		t[0].rx_buf = buf;
  		t[0].len = chunk_len;
  		t[0].cs_change = true;
  		spi_message_add_tail(&t[0], &m);
  
  		spi_sync(to_spi_device(glue->dev), &m);
  
  		if (!fixed)
  			addr += chunk_len;
  		buf += chunk_len;
  		len -= chunk_len;
  	}
  
  	return 0;
  }
  
  static int __must_check wl12xx_spi_raw_write(struct device *child, int addr,
  					     void *buf, size_t len, bool fixed)
  {
  	struct wl12xx_spi_glue *glue = dev_get_drvdata(child->parent);
  	/* SPI write buffers - 2 for each chunk */
  	struct spi_transfer t[2 * WSPI_MAX_NUM_OF_CHUNKS];
  	struct spi_message m;
  	u32 commands[WSPI_MAX_NUM_OF_CHUNKS]; /* 1 command per chunk */
  	u32 *cmd;
  	u32 chunk_len;
  	int i;
  
  	WARN_ON(len > SPI_AGGR_BUFFER_SIZE);
  
  	spi_message_init(&m);
  	memset(t, 0, sizeof(t));
  
  	cmd = &commands[0];
  	i = 0;
  	while (len > 0) {
  		chunk_len = min_t(size_t, WSPI_MAX_CHUNK_SIZE, len);
  
  		*cmd = 0;
  		*cmd |= WSPI_CMD_WRITE;
  		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
  			WSPI_CMD_BYTE_LENGTH;
  		*cmd |= addr & WSPI_CMD_BYTE_ADDR;
  
  		if (fixed)
  			*cmd |= WSPI_CMD_FIXED;
  
  		t[i].tx_buf = cmd;
  		t[i].len = sizeof(*cmd);
  		spi_message_add_tail(&t[i++], &m);
  
  		t[i].tx_buf = buf;
  		t[i].len = chunk_len;
  		spi_message_add_tail(&t[i++], &m);
  
  		if (!fixed)
  			addr += chunk_len;
  		buf += chunk_len;
  		len -= chunk_len;
  		cmd++;
  	}
  
  	spi_sync(to_spi_device(glue->dev), &m);
  
  	return 0;
  }
  
  static struct wl1271_if_operations spi_ops = {
  	.read		= wl12xx_spi_raw_read,
  	.write		= wl12xx_spi_raw_write,
  	.reset		= wl12xx_spi_reset,
  	.init		= wl12xx_spi_init,
  	.set_block_size = NULL,
  };
  
  static int wl1271_probe(struct spi_device *spi)
  {
  	struct wl12xx_spi_glue *glue;
  	struct wlcore_platdev_data pdev_data;
  	struct resource res[1];
  	int ret;
  
  	memset(&pdev_data, 0x00, sizeof(pdev_data));
  
  	/* TODO: add DT parsing when needed */
  
  	pdev_data.if_ops = &spi_ops;
  
  	glue = devm_kzalloc(&spi->dev, sizeof(*glue), GFP_KERNEL);
  	if (!glue) {
  		dev_err(&spi->dev, "can't allocate glue\n");
  		return -ENOMEM;
  	}
  
  	glue->dev = &spi->dev;
  
  	spi_set_drvdata(spi, glue);
  
  	/* This is the only SPI value that we need to set here, the rest
  	 * comes from the board-peripherals file */
  	spi->bits_per_word = 32;
  
  	ret = spi_setup(spi);
  	if (ret < 0) {
  		dev_err(glue->dev, "spi_setup failed\n");
  		return ret;
  	}
  
  	glue->core = platform_device_alloc("wl12xx", PLATFORM_DEVID_AUTO);
  	if (!glue->core) {
  		dev_err(glue->dev, "can't allocate platform_device\n");
  		return -ENOMEM;
  	}
  
  	glue->core->dev.parent = &spi->dev;
  
  	memset(res, 0x00, sizeof(res));
  
  	res[0].start = spi->irq;
  	res[0].flags = IORESOURCE_IRQ;
  	res[0].name = "irq";
  
  	ret = platform_device_add_resources(glue->core, res, ARRAY_SIZE(res));
  	if (ret) {
  		dev_err(glue->dev, "can't add resources\n");
  		goto out_dev_put;
  	}
  
  	ret = platform_device_add_data(glue->core, &pdev_data,
  				       sizeof(pdev_data));
  	if (ret) {
  		dev_err(glue->dev, "can't add platform data\n");
  		goto out_dev_put;
  	}
  
  	ret = platform_device_add(glue->core);
  	if (ret) {
  		dev_err(glue->dev, "can't register platform device\n");
  		goto out_dev_put;
  	}
  
  	return 0;
  
  out_dev_put:
  	platform_device_put(glue->core);
  	return ret;
  }
  
  static int wl1271_remove(struct spi_device *spi)
  {
  	struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
  
  	platform_device_unregister(glue->core);
  
  	return 0;
  }
  
  
  static struct spi_driver wl1271_spi_driver = {
  	.driver = {
  		.name		= "wl1271_spi",
  	},
  
  	.probe		= wl1271_probe,
  	.remove		= wl1271_remove,
  };
  
  module_spi_driver(wl1271_spi_driver);
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Luciano Coelho <coelho@ti.com>");
  MODULE_AUTHOR("Juuso Oikarinen <juuso.oikarinen@nokia.com>");
  MODULE_ALIAS("spi:wl1271");
  