linux_dsm_epyc7002/drivers/net/wireless/cw1200/hwio.c
Solomon Peachy aec8e88c94 cw1200: Don't perform SPI transfers in interrupt context
When we get an interrupt from the hardware, the first thing the driver does
is tell the device to mask off the interrupt line.  Unfortunately this
involves a SPI transaction in interrupt context.  Some (most?) SPI
controllers perform the transfer asynchronously and try to sleep.
This is bad, and triggers a BUG().

So, work around this by using adding a hwbus hook for the cw1200 driver
core to call.  The cw1200_spi driver translates this into
irq_disable()/irq_enable() calls instead, which can safely be called in
interrupt context.

Apparently the platforms I used to develop the cw1200_spi driver used
synchronous spi_sync() implementations, which is why this didn't surface
until now.

Many thanks to Dave Sizeburns for the inital bug report and his services
as a tester.

Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2013-09-09 14:40:53 -04:00

328 lines
7.7 KiB
C

/*
* Low-level device IO routines for ST-Ericsson CW1200 drivers
*
* Copyright (c) 2010, ST-Ericsson
* Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
*
* Based on:
* ST-Ericsson UMAC CW1200 driver, which is
* Copyright (c) 2010, ST-Ericsson
* Author: Ajitpal Singh <ajitpal.singh@lockless.no>
*
* 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.
*/
#include <linux/types.h>
#include "cw1200.h"
#include "hwio.h"
#include "hwbus.h"
/* Sdio addr is 4*spi_addr */
#define SPI_REG_ADDR_TO_SDIO(spi_reg_addr) ((spi_reg_addr) << 2)
#define SDIO_ADDR17BIT(buf_id, mpf, rfu, reg_id_ofs) \
((((buf_id) & 0x1F) << 7) \
| (((mpf) & 1) << 6) \
| (((rfu) & 1) << 5) \
| (((reg_id_ofs) & 0x1F) << 0))
#define MAX_RETRY 3
static int __cw1200_reg_read(struct cw1200_common *priv, u16 addr,
void *buf, size_t buf_len, int buf_id)
{
u16 addr_sdio;
u32 sdio_reg_addr_17bit;
/* Check if buffer is aligned to 4 byte boundary */
if (WARN_ON(((unsigned long)buf & 3) && (buf_len > 4))) {
pr_err("buffer is not aligned.\n");
return -EINVAL;
}
/* Convert to SDIO Register Address */
addr_sdio = SPI_REG_ADDR_TO_SDIO(addr);
sdio_reg_addr_17bit = SDIO_ADDR17BIT(buf_id, 0, 0, addr_sdio);
return priv->hwbus_ops->hwbus_memcpy_fromio(priv->hwbus_priv,
sdio_reg_addr_17bit,
buf, buf_len);
}
static int __cw1200_reg_write(struct cw1200_common *priv, u16 addr,
const void *buf, size_t buf_len, int buf_id)
{
u16 addr_sdio;
u32 sdio_reg_addr_17bit;
/* Convert to SDIO Register Address */
addr_sdio = SPI_REG_ADDR_TO_SDIO(addr);
sdio_reg_addr_17bit = SDIO_ADDR17BIT(buf_id, 0, 0, addr_sdio);
return priv->hwbus_ops->hwbus_memcpy_toio(priv->hwbus_priv,
sdio_reg_addr_17bit,
buf, buf_len);
}
static inline int __cw1200_reg_read_32(struct cw1200_common *priv,
u16 addr, u32 *val)
{
__le32 tmp;
int i = __cw1200_reg_read(priv, addr, &tmp, sizeof(tmp), 0);
*val = le32_to_cpu(tmp);
return i;
}
static inline int __cw1200_reg_write_32(struct cw1200_common *priv,
u16 addr, u32 val)
{
__le32 tmp = cpu_to_le32(val);
return __cw1200_reg_write(priv, addr, &tmp, sizeof(tmp), 0);
}
static inline int __cw1200_reg_read_16(struct cw1200_common *priv,
u16 addr, u16 *val)
{
__le16 tmp;
int i = __cw1200_reg_read(priv, addr, &tmp, sizeof(tmp), 0);
*val = le16_to_cpu(tmp);
return i;
}
static inline int __cw1200_reg_write_16(struct cw1200_common *priv,
u16 addr, u16 val)
{
__le16 tmp = cpu_to_le16(val);
return __cw1200_reg_write(priv, addr, &tmp, sizeof(tmp), 0);
}
int cw1200_reg_read(struct cw1200_common *priv, u16 addr, void *buf,
size_t buf_len)
{
int ret;
priv->hwbus_ops->lock(priv->hwbus_priv);
ret = __cw1200_reg_read(priv, addr, buf, buf_len, 0);
priv->hwbus_ops->unlock(priv->hwbus_priv);
return ret;
}
int cw1200_reg_write(struct cw1200_common *priv, u16 addr, const void *buf,
size_t buf_len)
{
int ret;
priv->hwbus_ops->lock(priv->hwbus_priv);
ret = __cw1200_reg_write(priv, addr, buf, buf_len, 0);
priv->hwbus_ops->unlock(priv->hwbus_priv);
return ret;
}
int cw1200_data_read(struct cw1200_common *priv, void *buf, size_t buf_len)
{
int ret, retry = 1;
int buf_id_rx = priv->buf_id_rx;
priv->hwbus_ops->lock(priv->hwbus_priv);
while (retry <= MAX_RETRY) {
ret = __cw1200_reg_read(priv,
ST90TDS_IN_OUT_QUEUE_REG_ID, buf,
buf_len, buf_id_rx + 1);
if (!ret) {
buf_id_rx = (buf_id_rx + 1) & 3;
priv->buf_id_rx = buf_id_rx;
break;
} else {
retry++;
mdelay(1);
pr_err("error :[%d]\n", ret);
}
}
priv->hwbus_ops->unlock(priv->hwbus_priv);
return ret;
}
int cw1200_data_write(struct cw1200_common *priv, const void *buf,
size_t buf_len)
{
int ret, retry = 1;
int buf_id_tx = priv->buf_id_tx;
priv->hwbus_ops->lock(priv->hwbus_priv);
while (retry <= MAX_RETRY) {
ret = __cw1200_reg_write(priv,
ST90TDS_IN_OUT_QUEUE_REG_ID, buf,
buf_len, buf_id_tx);
if (!ret) {
buf_id_tx = (buf_id_tx + 1) & 31;
priv->buf_id_tx = buf_id_tx;
break;
} else {
retry++;
mdelay(1);
pr_err("error :[%d]\n", ret);
}
}
priv->hwbus_ops->unlock(priv->hwbus_priv);
return ret;
}
int cw1200_indirect_read(struct cw1200_common *priv, u32 addr, void *buf,
size_t buf_len, u32 prefetch, u16 port_addr)
{
u32 val32 = 0;
int i, ret;
if ((buf_len / 2) >= 0x1000) {
pr_err("Can't read more than 0xfff words.\n");
return -EINVAL;
}
priv->hwbus_ops->lock(priv->hwbus_priv);
/* Write address */
ret = __cw1200_reg_write_32(priv, ST90TDS_SRAM_BASE_ADDR_REG_ID, addr);
if (ret < 0) {
pr_err("Can't write address register.\n");
goto out;
}
/* Read CONFIG Register Value - We will read 32 bits */
ret = __cw1200_reg_read_32(priv, ST90TDS_CONFIG_REG_ID, &val32);
if (ret < 0) {
pr_err("Can't read config register.\n");
goto out;
}
/* Set PREFETCH bit */
ret = __cw1200_reg_write_32(priv, ST90TDS_CONFIG_REG_ID,
val32 | prefetch);
if (ret < 0) {
pr_err("Can't write prefetch bit.\n");
goto out;
}
/* Check for PRE-FETCH bit to be cleared */
for (i = 0; i < 20; i++) {
ret = __cw1200_reg_read_32(priv, ST90TDS_CONFIG_REG_ID, &val32);
if (ret < 0) {
pr_err("Can't check prefetch bit.\n");
goto out;
}
if (!(val32 & prefetch))
break;
mdelay(i);
}
if (val32 & prefetch) {
pr_err("Prefetch bit is not cleared.\n");
goto out;
}
/* Read data port */
ret = __cw1200_reg_read(priv, port_addr, buf, buf_len, 0);
if (ret < 0) {
pr_err("Can't read data port.\n");
goto out;
}
out:
priv->hwbus_ops->unlock(priv->hwbus_priv);
return ret;
}
int cw1200_apb_write(struct cw1200_common *priv, u32 addr, const void *buf,
size_t buf_len)
{
int ret;
if ((buf_len / 2) >= 0x1000) {
pr_err("Can't write more than 0xfff words.\n");
return -EINVAL;
}
priv->hwbus_ops->lock(priv->hwbus_priv);
/* Write address */
ret = __cw1200_reg_write_32(priv, ST90TDS_SRAM_BASE_ADDR_REG_ID, addr);
if (ret < 0) {
pr_err("Can't write address register.\n");
goto out;
}
/* Write data port */
ret = __cw1200_reg_write(priv, ST90TDS_SRAM_DPORT_REG_ID,
buf, buf_len, 0);
if (ret < 0) {
pr_err("Can't write data port.\n");
goto out;
}
out:
priv->hwbus_ops->unlock(priv->hwbus_priv);
return ret;
}
int __cw1200_irq_enable(struct cw1200_common *priv, int enable)
{
u32 val32;
u16 val16;
int ret;
/* We need to do this hack because the SPI layer can sleep on I/O
and the general path involves I/O to the device in interrupt
context.
However, the initial enable call needs to go to the hardware.
We don't worry about shutdown because we do a full reset which
clears the interrupt enabled bits.
*/
if (priv->hwbus_ops->irq_enable) {
ret = priv->hwbus_ops->irq_enable(priv->hwbus_priv, enable);
if (ret || enable < 2)
return ret;
}
if (HIF_8601_SILICON == priv->hw_type) {
ret = __cw1200_reg_read_32(priv, ST90TDS_CONFIG_REG_ID, &val32);
if (ret < 0) {
pr_err("Can't read config register.\n");
return ret;
}
if (enable)
val32 |= ST90TDS_CONF_IRQ_RDY_ENABLE;
else
val32 &= ~ST90TDS_CONF_IRQ_RDY_ENABLE;
ret = __cw1200_reg_write_32(priv, ST90TDS_CONFIG_REG_ID, val32);
if (ret < 0) {
pr_err("Can't write config register.\n");
return ret;
}
} else {
ret = __cw1200_reg_read_16(priv, ST90TDS_CONFIG_REG_ID, &val16);
if (ret < 0) {
pr_err("Can't read control register.\n");
return ret;
}
if (enable)
val16 |= ST90TDS_CONT_IRQ_RDY_ENABLE;
else
val16 &= ~ST90TDS_CONT_IRQ_RDY_ENABLE;
ret = __cw1200_reg_write_16(priv, ST90TDS_CONFIG_REG_ID, val16);
if (ret < 0) {
pr_err("Can't write control register.\n");
return ret;
}
}
return 0;
}