/*
- * drivers/i2c/i2c-ibm_iic.c
+ * drivers/i2c/busses/i2c-ibm_iic.c
*
* Support for the IIC peripheral on IBM PPC 4xx
*
*
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include "i2c-ibm_iic.h"
-#define DRIVER_VERSION "2.01"
+#define DRIVER_VERSION "2.1"
MODULE_DESCRIPTION("IBM IIC driver v" DRIVER_VERSION);
MODULE_LICENSE("GPL");
-static int iic_force_poll = 0;
-MODULE_PARM(iic_force_poll, "i");
+static int iic_force_poll;
+module_param(iic_force_poll, bool, 0);
MODULE_PARM_DESC(iic_force_poll, "Force polling mode");
-static int iic_force_fast = 0;
-MODULE_PARM(iic_force_fast, "i");
+static int iic_force_fast;
+module_param(iic_force_fast, bool, 0);
MODULE_PARM_DESC(iic_fast_poll, "Force fast mode (400 kHz)");
#define DBG_LEVEL 0
#if DBG_LEVEL > 2
static void dump_iic_regs(const char* header, struct ibm_iic_private* dev)
{
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
printk(KERN_DEBUG "ibm-iic%d: %s\n", dev->idx, header);
printk(KERN_DEBUG " cntl = 0x%02x, mdcntl = 0x%02x\n"
KERN_DEBUG " sts = 0x%02x, extsts = 0x%02x\n"
# define DUMP_REGS(h,dev) ((void)0)
#endif
+/* Bus timings (in ns) for bit-banging */
+static struct i2c_timings {
+ unsigned int hd_sta;
+ unsigned int su_sto;
+ unsigned int low;
+ unsigned int high;
+ unsigned int buf;
+} timings [] = {
+/* Standard mode (100 KHz) */
+{
+ .hd_sta = 4000,
+ .su_sto = 4000,
+ .low = 4700,
+ .high = 4000,
+ .buf = 4700,
+},
+/* Fast mode (400 KHz) */
+{
+ .hd_sta = 600,
+ .su_sto = 600,
+ .low = 1300,
+ .high = 600,
+ .buf = 1300,
+}};
+
/* Enable/disable interrupt generation */
static inline void iic_interrupt_mode(struct ibm_iic_private* dev, int enable)
{
*/
static void iic_dev_init(struct ibm_iic_private* dev)
{
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
DBG("%d: init\n", dev->idx);
*/
static void iic_dev_reset(struct ibm_iic_private* dev)
{
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
int i;
u8 dc;
iic_dev_init(dev);
}
+/*
+ * Do 0-length transaction using bit-banging through IIC_DIRECTCNTL register.
+ */
+
+/* Wait for SCL and/or SDA to be high */
+static int iic_dc_wait(volatile struct iic_regs __iomem *iic, u8 mask)
+{
+ unsigned long x = jiffies + HZ / 28 + 2;
+ while ((in_8(&iic->directcntl) & mask) != mask){
+ if (unlikely(time_after(jiffies, x)))
+ return -1;
+ cond_resched();
+ }
+ return 0;
+}
+
+static int iic_smbus_quick(struct ibm_iic_private* dev, const struct i2c_msg* p)
+{
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
+ const struct i2c_timings* t = &timings[dev->fast_mode ? 1 : 0];
+ u8 mask, v, sda;
+ int i, res;
+
+ /* Only 7-bit addresses are supported */
+ if (unlikely(p->flags & I2C_M_TEN)){
+ DBG("%d: smbus_quick - 10 bit addresses are not supported\n",
+ dev->idx);
+ return -EINVAL;
+ }
+
+ DBG("%d: smbus_quick(0x%02x)\n", dev->idx, p->addr);
+
+ /* Reset IIC interface */
+ out_8(&iic->xtcntlss, XTCNTLSS_SRST);
+
+ /* Wait for bus to become free */
+ out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
+ if (unlikely(iic_dc_wait(iic, DIRCNTL_MSDA | DIRCNTL_MSC)))
+ goto err;
+ ndelay(t->buf);
+
+ /* START */
+ out_8(&iic->directcntl, DIRCNTL_SCC);
+ sda = 0;
+ ndelay(t->hd_sta);
+
+ /* Send address */
+ v = (u8)((p->addr << 1) | ((p->flags & I2C_M_RD) ? 1 : 0));
+ for (i = 0, mask = 0x80; i < 8; ++i, mask >>= 1){
+ out_8(&iic->directcntl, sda);
+ ndelay(t->low / 2);
+ sda = (v & mask) ? DIRCNTL_SDAC : 0;
+ out_8(&iic->directcntl, sda);
+ ndelay(t->low / 2);
+
+ out_8(&iic->directcntl, DIRCNTL_SCC | sda);
+ if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
+ goto err;
+ ndelay(t->high);
+ }
+
+ /* ACK */
+ out_8(&iic->directcntl, sda);
+ ndelay(t->low / 2);
+ out_8(&iic->directcntl, DIRCNTL_SDAC);
+ ndelay(t->low / 2);
+ out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
+ if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
+ goto err;
+ res = (in_8(&iic->directcntl) & DIRCNTL_MSDA) ? -EREMOTEIO : 1;
+ ndelay(t->high);
+
+ /* STOP */
+ out_8(&iic->directcntl, 0);
+ ndelay(t->low);
+ out_8(&iic->directcntl, DIRCNTL_SCC);
+ if (unlikely(iic_dc_wait(iic, DIRCNTL_MSC)))
+ goto err;
+ ndelay(t->su_sto);
+ out_8(&iic->directcntl, DIRCNTL_SDAC | DIRCNTL_SCC);
+
+ ndelay(t->buf);
+
+ DBG("%d: smbus_quick -> %s\n", dev->idx, res ? "NACK" : "ACK");
+out:
+ /* Remove reset */
+ out_8(&iic->xtcntlss, 0);
+
+ /* Reinitialize interface */
+ iic_dev_init(dev);
+
+ return res;
+err:
+ DBG("%d: smbus_quick - bus is stuck\n", dev->idx);
+ res = -EREMOTEIO;
+ goto out;
+}
+
/*
* IIC interrupt handler
*/
-static irqreturn_t iic_handler(int irq, void *dev_id, struct pt_regs *regs)
+static irqreturn_t iic_handler(int irq, void *dev_id)
{
struct ibm_iic_private* dev = (struct ibm_iic_private*)dev_id;
- volatile struct iic_regs* iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
DBG2("%d: irq handler, STS = 0x%02x, EXTSTS = 0x%02x\n",
dev->idx, in_8(&iic->sts), in_8(&iic->extsts));
*/
static int iic_xfer_result(struct ibm_iic_private* dev)
{
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
if (unlikely(in_8(&iic->sts) & STS_ERR)){
DBG("%d: xfer error, EXTSTS = 0x%02x\n", dev->idx,
*/
static void iic_abort_xfer(struct ibm_iic_private* dev)
{
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
unsigned long x;
DBG("%d: iic_abort_xfer\n", dev->idx);
*/
static int iic_wait_for_tc(struct ibm_iic_private* dev){
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
int ret = 0;
if (dev->irq >= 0){
/* Interrupt mode */
- wait_queue_t wait;
- init_waitqueue_entry(&wait, current);
-
- add_wait_queue(&dev->wq, &wait);
- set_current_state(TASK_INTERRUPTIBLE);
- if (in_8(&iic->sts) & STS_PT)
- schedule_timeout(dev->adap.timeout * HZ);
- set_current_state(TASK_RUNNING);
- remove_wait_queue(&dev->wq, &wait);
-
- if (unlikely(signal_pending(current))){
+ ret = wait_event_interruptible_timeout(dev->wq,
+ !(in_8(&iic->sts) & STS_PT), dev->adap.timeout * HZ);
+
+ if (unlikely(ret < 0))
DBG("%d: wait interrupted\n", dev->idx);
- ret = -ERESTARTSYS;
- } else if (unlikely(in_8(&iic->sts) & STS_PT)){
+ else if (unlikely(in_8(&iic->sts) & STS_PT)){
DBG("%d: wait timeout\n", dev->idx);
ret = -ETIMEDOUT;
}
static int iic_xfer_bytes(struct ibm_iic_private* dev, struct i2c_msg* pm,
int combined_xfer)
{
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
char* buf = pm->buf;
int i, j, loops, ret = 0;
int len = pm->len;
if (!(cntl & CNTL_RW))
for (j = 0; j < count; ++j)
- out_8((volatile u8*)&iic->mdbuf, *buf++);
+ out_8((void __iomem *)&iic->mdbuf, *buf++);
if (i < loops - 1)
cmd |= CNTL_CHT;
if (cntl & CNTL_RW)
for (j = 0; j < count; ++j)
- *buf++ = in_8((volatile u8*)&iic->mdbuf);
+ *buf++ = in_8((void __iomem *)&iic->mdbuf);
}
return ret > 0 ? 0 : ret;
*/
static inline void iic_address(struct ibm_iic_private* dev, struct i2c_msg* msg)
{
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
u16 addr = msg->addr;
DBG2("%d: iic_address, 0x%03x (%d-bit)\n", dev->idx,
* Generic master transfer entrypoint.
* Returns the number of processed messages or error (<0)
*/
-static int iic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+static int iic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct ibm_iic_private* dev = (struct ibm_iic_private*)(i2c_get_adapdata(adap));
- volatile struct iic_regs *iic = dev->vaddr;
+ volatile struct iic_regs __iomem *iic = dev->vaddr;
int i, ret = 0;
DBG2("%d: iic_xfer, %d msg(s)\n", dev->idx, num);
if (unlikely(msgs[i].len <= 0)){
if (num == 1 && !msgs[0].len){
/* Special case for I2C_SMBUS_QUICK emulation.
- * Although this logic is FAR FROM PERFECT, this
- * is what previous driver version did.
* IBM IIC doesn't support 0-length transactions
- * (except bit-banging through IICx_DIRECTCNTL).
+ * so we have to emulate them using bit-banging.
*/
- DBG("%d: zero-length msg kludge\n", dev->idx);
- return 0;
+ return iic_smbus_quick(dev, &msgs[0]);
}
DBG("%d: invalid len %d in msg[%d]\n", dev->idx,
msgs[i].len, i);
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR;
}
-static struct i2c_algorithm iic_algo = {
- .name = "IBM IIC algorithm",
- .id = I2C_ALGO_OCP,
+static const struct i2c_algorithm iic_algo = {
.master_xfer = iic_xfer,
- .smbus_xfer = NULL,
- .slave_send = NULL,
- .slave_recv = NULL,
- .algo_control = NULL,
.functionality = iic_func
};
printk(KERN_WARNING"ibm-iic%d: missing additional data!\n",
ocp->def->index);
- if (!(dev = kmalloc(sizeof(*dev), GFP_KERNEL))){
+ if (!(dev = kzalloc(sizeof(*dev), GFP_KERNEL))) {
printk(KERN_CRIT "ibm-iic%d: failed to allocate device data\n",
ocp->def->index);
return -ENOMEM;
}
- memset(dev, 0, sizeof(*dev));
dev->idx = ocp->def->index;
ocp_set_drvdata(ocp, dev);
+ if (!request_mem_region(ocp->def->paddr, sizeof(struct iic_regs),
+ "ibm_iic")) {
+ ret = -EBUSY;
+ goto fail1;
+ }
+
if (!(dev->vaddr = ioremap(ocp->def->paddr, sizeof(struct iic_regs)))){
printk(KERN_CRIT "ibm-iic%d: failed to ioremap device registers\n",
dev->idx);
dev->irq = iic_force_poll ? -1 : ocp->def->irq;
if (dev->irq >= 0){
- /* Disable interrupts until we finish intialization,
+ /* Disable interrupts until we finish initialization,
assumes level-sensitive IRQ setup...
*/
iic_interrupt_mode(dev, 0);
adap = &dev->adap;
strcpy(adap->name, "IBM IIC");
i2c_set_adapdata(adap, dev);
- adap->id = I2C_HW_OCP | iic_algo.id;
+ adap->id = I2C_HW_OCP;
+ adap->class = I2C_CLASS_HWMON;
adap->algo = &iic_algo;
adap->client_register = NULL;
adap->client_unregister = NULL;
free_irq(dev->irq, dev);
}
- iounmap((void*)dev->vaddr);
+ iounmap(dev->vaddr);
fail2:
- ocp_set_drvdata(ocp, 0);
+ release_mem_region(ocp->def->paddr, sizeof(struct iic_regs));
+fail1:
+ ocp_set_drvdata(ocp, NULL);
kfree(dev);
return ret;
}
iic_interrupt_mode(dev, 0);
free_irq(dev->irq, dev);
}
- iounmap((void*)dev->vaddr);
+ iounmap(dev->vaddr);
+ release_mem_region(ocp->def->paddr, sizeof(struct iic_regs));
kfree(dev);
}
}
git://git.onelab.eu / linux-2.6.git / blobdiff