OpenWrt – Rev 4
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/*
* B53 register access through Switch Register Access Bridge Registers
*
* Copyright (C) 2013 Hauke Mehrtens <hauke@hauke-m.de>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/platform_data/b53.h>
#include "b53_priv.h"
/* command and status register of the SRAB */
#define B53_SRAB_CMDSTAT 0x2c
#define B53_SRAB_CMDSTAT_RST BIT(2)
#define B53_SRAB_CMDSTAT_WRITE BIT(1)
#define B53_SRAB_CMDSTAT_GORDYN BIT(0)
#define B53_SRAB_CMDSTAT_PAGE 24
#define B53_SRAB_CMDSTAT_REG 16
/* high order word of write data to switch registe */
#define B53_SRAB_WD_H 0x30
/* low order word of write data to switch registe */
#define B53_SRAB_WD_L 0x34
/* high order word of read data from switch register */
#define B53_SRAB_RD_H 0x38
/* low order word of read data from switch register */
#define B53_SRAB_RD_L 0x3c
/* command and status register of the SRAB */
#define B53_SRAB_CTRLS 0x40
#define B53_SRAB_CTRLS_RCAREQ BIT(3)
#define B53_SRAB_CTRLS_RCAGNT BIT(4)
#define B53_SRAB_CTRLS_SW_INIT_DONE BIT(6)
/* the register captures interrupt pulses from the switch */
#define B53_SRAB_INTR 0x44
static int b53_srab_request_grant(struct b53_device *dev)
{
u8 __iomem *regs = dev->priv;
u32 ctrls;
int i;
ctrls = readl(regs + B53_SRAB_CTRLS);
ctrls |= B53_SRAB_CTRLS_RCAREQ;
writel(ctrls, regs + B53_SRAB_CTRLS);
for (i = 0; i < 20; i++) {
ctrls = readl(regs + B53_SRAB_CTRLS);
if (ctrls & B53_SRAB_CTRLS_RCAGNT)
break;
usleep_range(10, 100);
}
if (WARN_ON(i == 5))
return -EIO;
return 0;
}
static void b53_srab_release_grant(struct b53_device *dev)
{
u8 __iomem *regs = dev->priv;
u32 ctrls;
ctrls = readl(regs + B53_SRAB_CTRLS);
ctrls &= ~B53_SRAB_CTRLS_RCAREQ;
writel(ctrls, regs + B53_SRAB_CTRLS);
}
static int b53_srab_op(struct b53_device *dev, u8 page, u8 reg, u32 op)
{
int i;
u32 cmdstat;
u8 __iomem *regs = dev->priv;
/* set register address */
cmdstat = (page << B53_SRAB_CMDSTAT_PAGE) |
(reg << B53_SRAB_CMDSTAT_REG) |
B53_SRAB_CMDSTAT_GORDYN |
op;
writel(cmdstat, regs + B53_SRAB_CMDSTAT);
/* check if operation completed */
for (i = 0; i < 5; ++i) {
cmdstat = readl(regs + B53_SRAB_CMDSTAT);
if (!(cmdstat & B53_SRAB_CMDSTAT_GORDYN))
break;
usleep_range(10, 100);
}
if (WARN_ON(i == 5))
return -EIO;
return 0;
}
static int b53_srab_read8(struct b53_device *dev, u8 page, u8 reg, u8 *val)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
ret = b53_srab_op(dev, page, reg, 0);
if (ret)
goto err;
*val = readl(regs + B53_SRAB_RD_L) & 0xff;
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_read16(struct b53_device *dev, u8 page, u8 reg, u16 *val)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
ret = b53_srab_op(dev, page, reg, 0);
if (ret)
goto err;
*val = readl(regs + B53_SRAB_RD_L) & 0xffff;
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_read32(struct b53_device *dev, u8 page, u8 reg, u32 *val)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
ret = b53_srab_op(dev, page, reg, 0);
if (ret)
goto err;
*val = readl(regs + B53_SRAB_RD_L);
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_read48(struct b53_device *dev, u8 page, u8 reg, u64 *val)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
ret = b53_srab_op(dev, page, reg, 0);
if (ret)
goto err;
*val = readl(regs + B53_SRAB_RD_L);
*val += ((u64)readl(regs + B53_SRAB_RD_H) & 0xffff) << 32;
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_read64(struct b53_device *dev, u8 page, u8 reg, u64 *val)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
ret = b53_srab_op(dev, page, reg, 0);
if (ret)
goto err;
*val = readl(regs + B53_SRAB_RD_L);
*val += (u64)readl(regs + B53_SRAB_RD_H) << 32;
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_write8(struct b53_device *dev, u8 page, u8 reg, u8 value)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
writel(value, regs + B53_SRAB_WD_L);
ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_write16(struct b53_device *dev, u8 page, u8 reg,
u16 value)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
writel(value, regs + B53_SRAB_WD_L);
ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_write32(struct b53_device *dev, u8 page, u8 reg,
u32 value)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
writel(value, regs + B53_SRAB_WD_L);
ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_write48(struct b53_device *dev, u8 page, u8 reg,
u64 value)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
writel((u32)value, regs + B53_SRAB_WD_L);
writel((u16)(value >> 32), regs + B53_SRAB_WD_H);
ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
err:
b53_srab_release_grant(dev);
return ret;
}
static int b53_srab_write64(struct b53_device *dev, u8 page, u8 reg,
u64 value)
{
u8 __iomem *regs = dev->priv;
int ret = 0;
ret = b53_srab_request_grant(dev);
if (ret)
goto err;
writel((u32)value, regs + B53_SRAB_WD_L);
writel((u32)(value >> 32), regs + B53_SRAB_WD_H);
ret = b53_srab_op(dev, page, reg, B53_SRAB_CMDSTAT_WRITE);
err:
b53_srab_release_grant(dev);
return ret;
}
static struct b53_io_ops b53_srab_ops = {
.read8 = b53_srab_read8,
.read16 = b53_srab_read16,
.read32 = b53_srab_read32,
.read48 = b53_srab_read48,
.read64 = b53_srab_read64,
.write8 = b53_srab_write8,
.write16 = b53_srab_write16,
.write32 = b53_srab_write32,
.write48 = b53_srab_write48,
.write64 = b53_srab_write64,
};
static int b53_srab_probe(struct platform_device *pdev)
{
struct b53_platform_data *pdata = pdev->dev.platform_data;
struct b53_device *dev;
if (!pdata)
return -EINVAL;
dev = b53_switch_alloc(&pdev->dev, &b53_srab_ops, pdata->regs);
if (!dev)
return -ENOMEM;
if (pdata)
dev->pdata = pdata;
platform_set_drvdata(pdev, dev);
return b53_switch_register(dev);
}
static int b53_srab_remove(struct platform_device *pdev)
{
struct b53_device *dev = platform_get_drvdata(pdev);
if (dev)
b53_switch_remove(dev);
return 0;
}
static struct platform_driver b53_srab_driver = {
.probe = b53_srab_probe,
.remove = b53_srab_remove,
.driver = {
.name = "b53-srab-switch",
},
};
module_platform_driver(b53_srab_driver);
MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
MODULE_DESCRIPTION("B53 Switch Register Access Bridge Registers (SRAB) access driver");
MODULE_LICENSE("Dual BSD/GPL");