Commit b7a36701 authored by Mike Rapoport's avatar Mike Rapoport Committed by Jean Delvare

i2c-pxa: Add polling transfer

Add polling I2C transfer implementation for PXA I2C. This is needed
for cases where I2C transactions have to occur at times interrups are
disabled.
Signed-off-by: default avatarMike Rapoport <mike@compulab.co.il>
Acked-by: default avatareric miao <eric.miao@marvell.com>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent cea443a8
......@@ -24,6 +24,7 @@
#include <asm/arch/ohci.h>
#include <asm/arch/pm.h>
#include <asm/arch/dma.h>
#include <asm/arch/i2c.h>
#include "generic.h"
#include "devices.h"
......@@ -423,6 +424,11 @@ struct platform_device pxa27x_device_i2c_power = {
.num_resources = ARRAY_SIZE(i2c_power_resources),
};
void __init pxa_set_i2c_power_info(struct i2c_pxa_platform_data *info)
{
pxa27x_device_i2c_power.dev.platform_data = info;
}
static struct platform_device *devices[] __initdata = {
&pxa_device_mci,
&pxa_device_udc,
......
......@@ -65,6 +65,7 @@ struct pxa_i2c {
unsigned long iosize;
int irq;
int use_pio;
};
#define _IBMR(i2c) ((i2c)->reg_base + 0)
......@@ -163,6 +164,7 @@ static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
#define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
{
......@@ -554,6 +556,71 @@ static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
writel(icr, _ICR(i2c));
}
static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
{
/* make timeout the same as for interrupt based functions */
long timeout = 2 * DEF_TIMEOUT;
/*
* Wait for the bus to become free.
*/
while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
udelay(1000);
show_state(i2c);
}
if (timeout <= 0) {
show_state(i2c);
dev_err(&i2c->adap.dev,
"i2c_pxa: timeout waiting for bus free\n");
return I2C_RETRY;
}
/*
* Set master mode.
*/
writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
return 0;
}
static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
struct i2c_msg *msg, int num)
{
unsigned long timeout = 500000; /* 5 seconds */
int ret = 0;
ret = i2c_pxa_pio_set_master(i2c);
if (ret)
goto out;
i2c->msg = msg;
i2c->msg_num = num;
i2c->msg_idx = 0;
i2c->msg_ptr = 0;
i2c->irqlogidx = 0;
i2c_pxa_start_message(i2c);
while (timeout-- && i2c->msg_num > 0) {
i2c_pxa_handler(0, i2c);
udelay(10);
}
i2c_pxa_stop_message(i2c);
/*
* We place the return code in i2c->msg_idx.
*/
ret = i2c->msg_idx;
out:
if (timeout == 0)
i2c_pxa_scream_blue_murder(i2c, "timeout");
return ret;
}
/*
* We are protected by the adapter bus mutex.
*/
......@@ -610,6 +677,35 @@ static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
return ret;
}
static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
struct i2c_msg msgs[], int num)
{
struct pxa_i2c *i2c = adap->algo_data;
int ret, i;
/* If the I2C controller is disabled we need to reset it
(probably due to a suspend/resume destroying state). We do
this here as we can then avoid worrying about resuming the
controller before its users. */
if (!(readl(_ICR(i2c)) & ICR_IUE))
i2c_pxa_reset(i2c);
for (i = adap->retries; i >= 0; i--) {
ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
if (ret != I2C_RETRY)
goto out;
if (i2c_debug)
dev_dbg(&adap->dev, "Retrying transmission\n");
udelay(100);
}
i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
ret = -EREMOTEIO;
out:
i2c_pxa_set_slave(i2c, ret);
return ret;
}
/*
* i2c_pxa_master_complete - complete the message and wake up.
*/
......@@ -621,6 +717,7 @@ static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
i2c->msg_num = 0;
if (ret)
i2c->msg_idx = ret;
if (!i2c->use_pio)
wake_up(&i2c->wait);
}
......@@ -840,6 +937,11 @@ static const struct i2c_algorithm i2c_pxa_algorithm = {
.functionality = i2c_pxa_functionality,
};
static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
.master_xfer = i2c_pxa_pio_xfer,
.functionality = i2c_pxa_functionality,
};
static void i2c_pxa_enable(struct platform_device *dev)
{
if (cpu_is_pxa27x()) {
......@@ -890,7 +992,6 @@ static int i2c_pxa_probe(struct platform_device *dev)
}
i2c->adap.owner = THIS_MODULE;
i2c->adap.algo = &i2c_pxa_algorithm;
i2c->adap.retries = 5;
spin_lock_init(&i2c->lock);
......@@ -927,20 +1028,26 @@ static int i2c_pxa_probe(struct platform_device *dev)
clk_enable(i2c->clk);
i2c_pxa_enable(dev);
if (plat) {
i2c->adap.class = plat->class;
i2c->use_pio = plat->use_pio;
}
if (i2c->use_pio) {
i2c->adap.algo = &i2c_pxa_pio_algorithm;
} else {
i2c->adap.algo = &i2c_pxa_algorithm;
ret = request_irq(irq, i2c_pxa_handler, IRQF_DISABLED,
i2c->adap.name, i2c);
if (ret)
goto ereqirq;
}
i2c_pxa_reset(i2c);
i2c->adap.algo_data = i2c;
i2c->adap.dev.parent = &dev->dev;
if (plat) {
i2c->adap.class = plat->class;
}
/*
* If "dev->id" is negative we consider it as zero.
* The reason to do so is to avoid sysfs names that only make
......@@ -966,6 +1073,7 @@ static int i2c_pxa_probe(struct platform_device *dev)
return 0;
eadapt:
if (!i2c->use_pio)
free_irq(irq, i2c);
ereqirq:
clk_disable(i2c->clk);
......@@ -986,6 +1094,7 @@ static int i2c_pxa_remove(struct platform_device *dev)
platform_set_drvdata(dev, NULL);
i2c_del_adapter(&i2c->adap);
if (!i2c->use_pio)
free_irq(i2c->irq, i2c);
clk_disable(i2c->clk);
......
......@@ -65,7 +65,13 @@ struct i2c_pxa_platform_data {
unsigned int slave_addr;
struct i2c_slave_client *slave;
unsigned int class;
int use_pio;
};
extern void pxa_set_i2c_info(struct i2c_pxa_platform_data *info);
#ifdef CONFIG_PXA27x
extern void pxa_set_i2c_power_info(struct i2c_pxa_platform_data *info);
#endif
#endif
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