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linux/drivers/net/wireless/ti/wlcore/spi.c
George Spelvin e757201b8d drivers/net/wireless/ti/wl*/spi.c: Simplify CRC computation 
These devices require commands stored in buffers in an odd order,
different from that in which the CRC is computed.

Rather than make two copies of the commands in two different orders,
form the commands in logical (CRC) order, append the CRC, then byte-swap
in place to the desired order.

The old code worked fine, I'm just scratching an "ugh, that's ugly"
itch.

Signed-off-by: George Spelvin <linux@horizon.com>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2014-05-16 14:26:53 -04:00

435 lines
10 KiB
C
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/*
* 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)
#define WSPI_MAX_NUM_OF_CHUNKS (SPI_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE)
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);
struct spi_transfer t[2 * (WSPI_MAX_NUM_OF_CHUNKS + 1)];
struct spi_message m;
u32 commands[WSPI_MAX_NUM_OF_CHUNKS];
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 = -ENOMEM;
memset(&pdev_data, 0x00, sizeof(pdev_data));
pdev_data.pdata = dev_get_platdata(&spi->dev);
if (!pdev_data.pdata) {
dev_err(&spi->dev, "no platform data\n");
ret = -ENODEV;
goto out;
}
pdev_data.if_ops = &spi_ops;
glue = kzalloc(sizeof(*glue), GFP_KERNEL);
if (!glue) {
dev_err(&spi->dev, "can't allocate glue\n");
goto out;
}
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");
goto out_free_glue;
}
glue->core = platform_device_alloc("wl12xx", PLATFORM_DEVID_AUTO);
if (!glue->core) {
dev_err(glue->dev, "can't allocate platform_device\n");
ret = -ENOMEM;
goto out_free_glue;
}
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);
out_free_glue:
kfree(glue);
out:
return ret;
}
static int wl1271_remove(struct spi_device *spi)
{
struct wl12xx_spi_glue *glue = spi_get_drvdata(spi);
platform_device_unregister(glue->core);
kfree(glue);
return 0;
}
static struct spi_driver wl1271_spi_driver = {
.driver = {
.name = "wl1271_spi",
.owner = THIS_MODULE,
},
.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");
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