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|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* netup_unidvb_i2c.c
*
* Internal I2C bus driver for NetUP Universal Dual DVB-CI
*
* Copyright (C) 2014 NetUP Inc.
* Copyright (C) 2014 Sergey Kozlov <serjk@netup.ru>
* Copyright (C) 2014 Abylay Ospan <aospan@netup.ru>
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include "netup_unidvb.h"
#define NETUP_I2C_BUS0_ADDR 0x4800
#define NETUP_I2C_BUS1_ADDR 0x4840
#define NETUP_I2C_TIMEOUT 1000
/* twi_ctrl0_stat reg bits */
#define TWI_IRQEN_COMPL 0x1
#define TWI_IRQEN_ANACK 0x2
#define TWI_IRQEN_DNACK 0x4
#define TWI_IRQ_COMPL (TWI_IRQEN_COMPL << 8)
#define TWI_IRQ_ANACK (TWI_IRQEN_ANACK << 8)
#define TWI_IRQ_DNACK (TWI_IRQEN_DNACK << 8)
#define TWI_IRQ_TX 0x800
#define TWI_IRQ_RX 0x1000
#define TWI_IRQEN (TWI_IRQEN_COMPL | TWI_IRQEN_ANACK | TWI_IRQEN_DNACK)
/* twi_addr_ctrl1 reg bits*/
#define TWI_TRANSFER 0x100
#define TWI_NOSTOP 0x200
#define TWI_SOFT_RESET 0x2000
/* twi_clkdiv reg value */
#define TWI_CLKDIV 156
/* fifo_stat_ctrl reg bits */
#define FIFO_IRQEN 0x8000
#define FIFO_RESET 0x4000
/* FIFO size */
#define FIFO_SIZE 16
struct netup_i2c_fifo_regs {
union {
__u8 data8;
__le16 data16;
__le32 data32;
};
__u8 padding[4];
__le16 stat_ctrl;
} __packed __aligned(1);
struct netup_i2c_regs {
__le16 clkdiv;
__le16 twi_ctrl0_stat;
__le16 twi_addr_ctrl1;
__le16 length;
__u8 padding1[8];
struct netup_i2c_fifo_regs tx_fifo;
__u8 padding2[6];
struct netup_i2c_fifo_regs rx_fifo;
} __packed __aligned(1);
irqreturn_t netup_i2c_interrupt(struct netup_i2c *i2c)
{
u16 reg, tmp;
unsigned long flags;
irqreturn_t iret = IRQ_HANDLED;
spin_lock_irqsave(&i2c->lock, flags);
reg = readw(&i2c->regs->twi_ctrl0_stat);
writew(reg & ~TWI_IRQEN, &i2c->regs->twi_ctrl0_stat);
dev_dbg(i2c->adap.dev.parent,
"%s(): twi_ctrl0_state 0x%x\n", __func__, reg);
if ((reg & TWI_IRQEN_COMPL) != 0 && (reg & TWI_IRQ_COMPL)) {
dev_dbg(i2c->adap.dev.parent,
"%s(): TWI_IRQEN_COMPL\n", __func__);
i2c->state = STATE_DONE;
goto irq_ok;
}
if ((reg & TWI_IRQEN_ANACK) != 0 && (reg & TWI_IRQ_ANACK)) {
dev_dbg(i2c->adap.dev.parent,
"%s(): TWI_IRQEN_ANACK\n", __func__);
i2c->state = STATE_ERROR;
goto irq_ok;
}
if ((reg & TWI_IRQEN_DNACK) != 0 && (reg & TWI_IRQ_DNACK)) {
dev_dbg(i2c->adap.dev.parent,
"%s(): TWI_IRQEN_DNACK\n", __func__);
i2c->state = STATE_ERROR;
goto irq_ok;
}
if ((reg & TWI_IRQ_RX) != 0) {
tmp = readw(&i2c->regs->rx_fifo.stat_ctrl);
writew(tmp & ~FIFO_IRQEN, &i2c->regs->rx_fifo.stat_ctrl);
i2c->state = STATE_WANT_READ;
dev_dbg(i2c->adap.dev.parent,
"%s(): want read\n", __func__);
goto irq_ok;
}
if ((reg & TWI_IRQ_TX) != 0) {
tmp = readw(&i2c->regs->tx_fifo.stat_ctrl);
writew(tmp & ~FIFO_IRQEN, &i2c->regs->tx_fifo.stat_ctrl);
i2c->state = STATE_WANT_WRITE;
dev_dbg(i2c->adap.dev.parent,
"%s(): want write\n", __func__);
goto irq_ok;
}
dev_warn(&i2c->adap.dev, "%s(): not mine interrupt\n", __func__);
iret = IRQ_NONE;
irq_ok:
spin_unlock_irqrestore(&i2c->lock, flags);
if (iret == IRQ_HANDLED)
wake_up(&i2c->wq);
return iret;
}
static void netup_i2c_reset(struct netup_i2c *i2c)
{
dev_dbg(i2c->adap.dev.parent, "%s()\n", __func__);
i2c->state = STATE_DONE;
writew(TWI_SOFT_RESET, &i2c->regs->twi_addr_ctrl1);
writew(TWI_CLKDIV, &i2c->regs->clkdiv);
writew(FIFO_RESET, &i2c->regs->tx_fifo.stat_ctrl);
writew(FIFO_RESET, &i2c->regs->rx_fifo.stat_ctrl);
writew(0x800, &i2c->regs->tx_fifo.stat_ctrl);
writew(0x800, &i2c->regs->rx_fifo.stat_ctrl);
}
static void netup_i2c_fifo_tx(struct netup_i2c *i2c)
{
u8 data;
u32 fifo_space = FIFO_SIZE -
(readw(&i2c->regs->tx_fifo.stat_ctrl) & 0x3f);
u32 msg_length = i2c->msg->len - i2c->xmit_size;
msg_length = (msg_length < fifo_space ? msg_length : fifo_space);
while (msg_length--) {
data = i2c->msg->buf[i2c->xmit_size++];
writeb(data, &i2c->regs->tx_fifo.data8);
dev_dbg(i2c->adap.dev.parent,
"%s(): write 0x%02x\n", __func__, data);
}
if (i2c->xmit_size < i2c->msg->len) {
dev_dbg(i2c->adap.dev.parent,
"%s(): TX IRQ enabled\n", __func__);
writew(readw(&i2c->regs->tx_fifo.stat_ctrl) | FIFO_IRQEN,
&i2c->regs->tx_fifo.stat_ctrl);
}
}
static void netup_i2c_fifo_rx(struct netup_i2c *i2c)
{
u8 data;
u32 fifo_size = readw(&i2c->regs->rx_fifo.stat_ctrl) & 0x3f;
dev_dbg(i2c->adap.dev.parent,
"%s(): RX fifo size %d\n", __func__, fifo_size);
while (fifo_size--) {
data = readb(&i2c->regs->rx_fifo.data8);
if ((i2c->msg->flags & I2C_M_RD) != 0 &&
i2c->xmit_size < i2c->msg->len) {
i2c->msg->buf[i2c->xmit_size++] = data;
dev_dbg(i2c->adap.dev.parent,
"%s(): read 0x%02x\n", __func__, data);
}
}
if (i2c->xmit_size < i2c->msg->len) {
dev_dbg(i2c->adap.dev.parent,
"%s(): RX IRQ enabled\n", __func__);
writew(readw(&i2c->regs->rx_fifo.stat_ctrl) | FIFO_IRQEN,
&i2c->regs->rx_fifo.stat_ctrl);
}
}
static void netup_i2c_start_xfer(struct netup_i2c *i2c)
{
u16 rdflag = ((i2c->msg->flags & I2C_M_RD) ? 1 : 0);
u16 reg = readw(&i2c->regs->twi_ctrl0_stat);
writew(TWI_IRQEN | reg, &i2c->regs->twi_ctrl0_stat);
writew(i2c->msg->len, &i2c->regs->length);
writew(TWI_TRANSFER | (i2c->msg->addr << 1) | rdflag,
&i2c->regs->twi_addr_ctrl1);
dev_dbg(i2c->adap.dev.parent,
"%s(): length %d twi_addr_ctrl1 0x%x twi_ctrl0_stat 0x%x\n",
__func__, readw(&i2c->regs->length),
readw(&i2c->regs->twi_addr_ctrl1),
readw(&i2c->regs->twi_ctrl0_stat));
i2c->state = STATE_WAIT;
i2c->xmit_size = 0;
if (!rdflag)
netup_i2c_fifo_tx(i2c);
else
writew(FIFO_IRQEN | readw(&i2c->regs->rx_fifo.stat_ctrl),
&i2c->regs->rx_fifo.stat_ctrl);
}
static int netup_i2c_xfer(struct i2c_adapter *adap,
struct i2c_msg *msgs, int num)
{
unsigned long flags;
int i, trans_done, res = num;
struct netup_i2c *i2c = i2c_get_adapdata(adap);
u16 reg;
spin_lock_irqsave(&i2c->lock, flags);
if (i2c->state != STATE_DONE) {
dev_dbg(i2c->adap.dev.parent,
"%s(): i2c->state == %d, resetting I2C\n",
__func__, i2c->state);
netup_i2c_reset(i2c);
}
dev_dbg(i2c->adap.dev.parent, "%s() num %d\n", __func__, num);
for (i = 0; i < num; i++) {
i2c->msg = &msgs[i];
netup_i2c_start_xfer(i2c);
trans_done = 0;
while (!trans_done) {
spin_unlock_irqrestore(&i2c->lock, flags);
if (wait_event_timeout(i2c->wq,
i2c->state != STATE_WAIT,
msecs_to_jiffies(NETUP_I2C_TIMEOUT))) {
spin_lock_irqsave(&i2c->lock, flags);
switch (i2c->state) {
case STATE_WANT_READ:
netup_i2c_fifo_rx(i2c);
break;
case STATE_WANT_WRITE:
netup_i2c_fifo_tx(i2c);
break;
case STATE_DONE:
if ((i2c->msg->flags & I2C_M_RD) != 0 &&
i2c->xmit_size != i2c->msg->len)
netup_i2c_fifo_rx(i2c);
dev_dbg(i2c->adap.dev.parent,
"%s(): msg %d OK\n",
__func__, i);
trans_done = 1;
break;
case STATE_ERROR:
res = -EIO;
dev_dbg(i2c->adap.dev.parent,
"%s(): error state\n",
__func__);
goto done;
default:
dev_dbg(i2c->adap.dev.parent,
"%s(): invalid state %d\n",
__func__, i2c->state);
res = -EINVAL;
goto done;
}
if (!trans_done) {
i2c->state = STATE_WAIT;
reg = readw(
&i2c->regs->twi_ctrl0_stat);
writew(TWI_IRQEN | reg,
&i2c->regs->twi_ctrl0_stat);
}
spin_unlock_irqrestore(&i2c->lock, flags);
} else {
spin_lock_irqsave(&i2c->lock, flags);
dev_dbg(i2c->adap.dev.parent,
"%s(): wait timeout\n", __func__);
res = -ETIMEDOUT;
goto done;
}
spin_lock_irqsave(&i2c->lock, flags);
}
}
done:
spin_unlock_irqrestore(&i2c->lock, flags);
dev_dbg(i2c->adap.dev.parent, "%s(): result %d\n", __func__, res);
return res;
}
static u32 netup_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_algorithm netup_i2c_algorithm = {
.master_xfer = netup_i2c_xfer,
.functionality = netup_i2c_func,
};
static const struct i2c_adapter netup_i2c_adapter = {
.owner = THIS_MODULE,
.name = NETUP_UNIDVB_NAME,
.class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
.algo = &netup_i2c_algorithm,
};
static int netup_i2c_init(struct netup_unidvb_dev *ndev, int bus_num)
{
int ret;
struct netup_i2c *i2c;
if (bus_num < 0 || bus_num > 1) {
dev_err(&ndev->pci_dev->dev,
"%s(): invalid bus_num %d\n", __func__, bus_num);
return -EINVAL;
}
i2c = &ndev->i2c[bus_num];
spin_lock_init(&i2c->lock);
init_waitqueue_head(&i2c->wq);
i2c->regs = (struct netup_i2c_regs __iomem *)(ndev->bmmio0 +
(bus_num == 0 ? NETUP_I2C_BUS0_ADDR : NETUP_I2C_BUS1_ADDR));
netup_i2c_reset(i2c);
i2c->adap = netup_i2c_adapter;
i2c->adap.dev.parent = &ndev->pci_dev->dev;
i2c_set_adapdata(&i2c->adap, i2c);
ret = i2c_add_adapter(&i2c->adap);
if (ret)
return ret;
dev_info(&ndev->pci_dev->dev,
"%s(): registered I2C bus %d at 0x%x\n",
__func__,
bus_num, (bus_num == 0 ?
NETUP_I2C_BUS0_ADDR :
NETUP_I2C_BUS1_ADDR));
return 0;
}
static void netup_i2c_remove(struct netup_unidvb_dev *ndev, int bus_num)
{
struct netup_i2c *i2c;
if (bus_num < 0 || bus_num > 1) {
dev_err(&ndev->pci_dev->dev,
"%s(): invalid bus number %d\n", __func__, bus_num);
return;
}
i2c = &ndev->i2c[bus_num];
netup_i2c_reset(i2c);
/* remove adapter */
i2c_del_adapter(&i2c->adap);
dev_info(&ndev->pci_dev->dev,
"netup_i2c_remove: unregistered I2C bus %d\n", bus_num);
}
int netup_i2c_register(struct netup_unidvb_dev *ndev)
{
int ret;
ret = netup_i2c_init(ndev, 0);
if (ret)
return ret;
ret = netup_i2c_init(ndev, 1);
if (ret) {
netup_i2c_remove(ndev, 0);
return ret;
}
return 0;
}
void netup_i2c_unregister(struct netup_unidvb_dev *ndev)
{
netup_i2c_remove(ndev, 0);
netup_i2c_remove(ndev, 1);
}
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