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path: root/drivers/i2c/busses/i2c-s3c2410.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
-rw-r--r--drivers/i2c/busses/i2c-s3c2410.c128
1 files changed, 99 insertions, 29 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index 3535f3c0f7b..e828a1dba0e 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -36,6 +36,7 @@
#include <linux/cpufreq.h>
#include <linux/slab.h>
#include <linux/io.h>
+#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
@@ -85,6 +86,7 @@
#define QUIRK_S3C2440 (1 << 0)
#define QUIRK_HDMIPHY (1 << 1)
#define QUIRK_NO_GPIO (1 << 2)
+#define QUIRK_POLL (1 << 3)
/* Max time to wait for bus to become idle after a xfer (in us) */
#define S3C2410_IDLE_TIMEOUT 5000
@@ -100,7 +102,7 @@ enum s3c24xx_i2c_state {
struct s3c24xx_i2c {
wait_queue_head_t wait;
- unsigned int quirks;
+ kernel_ulong_t quirks;
unsigned int suspended:1;
struct i2c_msg *msg;
@@ -122,7 +124,7 @@ struct s3c24xx_i2c {
struct s3c2410_platform_i2c *pdata;
int gpios[2];
struct pinctrl *pctrl;
-#ifdef CONFIG_CPU_FREQ
+#if defined(CONFIG_ARM_S3C24XX_CPUFREQ)
struct notifier_block freq_transition;
#endif
};
@@ -141,6 +143,8 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
};
MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
+static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat);
+
#ifdef CONFIG_OF
static const struct of_device_id s3c24xx_i2c_match[] = {
{ .compatible = "samsung,s3c2410-i2c", .data = (void *)0 },
@@ -149,6 +153,8 @@ static const struct of_device_id s3c24xx_i2c_match[] = {
.data = (void *)(QUIRK_S3C2440 | QUIRK_HDMIPHY | QUIRK_NO_GPIO) },
{ .compatible = "samsung,exynos5440-i2c",
.data = (void *)(QUIRK_S3C2440 | QUIRK_NO_GPIO) },
+ { .compatible = "samsung,exynos5-sata-phy-i2c",
+ .data = (void *)(QUIRK_S3C2440 | QUIRK_POLL | QUIRK_NO_GPIO) },
{},
};
MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
@@ -159,12 +165,12 @@ MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
* Get controller type either from device tree or platform device variant.
*/
-static inline unsigned int s3c24xx_get_device_quirks(struct platform_device *pdev)
+static inline kernel_ulong_t s3c24xx_get_device_quirks(struct platform_device *pdev)
{
if (pdev->dev.of_node) {
const struct of_device_id *match;
match = of_match_node(s3c24xx_i2c_match, pdev->dev.of_node);
- return (unsigned int)match->data;
+ return (kernel_ulong_t)match->data;
}
return platform_get_device_id(pdev)->driver_data;
@@ -187,7 +193,8 @@ static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret)
if (ret)
i2c->msg_idx = ret;
- wake_up(&i2c->wait);
+ if (!(i2c->quirks & QUIRK_POLL))
+ wake_up(&i2c->wait);
}
static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c)
@@ -224,6 +231,22 @@ static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c)
writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
}
+static bool is_ack(struct s3c24xx_i2c *i2c)
+{
+ int tries;
+
+ for (tries = 50; tries; --tries) {
+ if (readl(i2c->regs + S3C2410_IICCON)
+ & S3C2410_IICCON_IRQPEND) {
+ if (!(readl(i2c->regs + S3C2410_IICSTAT)
+ & S3C2410_IICSTAT_LASTBIT))
+ return true;
+ }
+ usleep_range(1000, 2000);
+ }
+ dev_err(i2c->dev, "ack was not recieved\n");
+ return false;
+}
/* s3c24xx_i2c_message_start
*
@@ -268,6 +291,16 @@ static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
stat |= S3C2410_IICSTAT_START;
writel(stat, i2c->regs + S3C2410_IICSTAT);
+
+ if (i2c->quirks & QUIRK_POLL) {
+ while ((i2c->msg_num != 0) && is_ack(i2c)) {
+ i2c_s3c_irq_nextbyte(i2c, stat);
+ stat = readl(i2c->regs + S3C2410_IICSTAT);
+
+ if (stat & S3C2410_IICSTAT_ARBITR)
+ dev_err(i2c->dev, "deal with arbitration loss\n");
+ }
+ }
}
static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret)
@@ -568,6 +601,31 @@ static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id)
return IRQ_HANDLED;
}
+/*
+ * Disable the bus so that we won't get any interrupts from now on, or try
+ * to drive any lines. This is the default state when we don't have
+ * anything to send/receive.
+ *
+ * If there is an event on the bus, or we have a pre-existing event at
+ * kernel boot time, we may not notice the event and the I2C controller
+ * will lock the bus with the I2C clock line low indefinitely.
+ */
+static inline void s3c24xx_i2c_disable_bus(struct s3c24xx_i2c *i2c)
+{
+ unsigned long tmp;
+
+ /* Stop driving the I2C pins */
+ tmp = readl(i2c->regs + S3C2410_IICSTAT);
+ tmp &= ~S3C2410_IICSTAT_TXRXEN;
+ writel(tmp, i2c->regs + S3C2410_IICSTAT);
+
+ /* We don't expect any interrupts now, and don't want send acks */
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp &= ~(S3C2410_IICCON_IRQEN | S3C2410_IICCON_IRQPEND |
+ S3C2410_IICCON_ACKEN);
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+}
+
/* s3c24xx_i2c_set_master
*
@@ -675,6 +733,15 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
s3c24xx_i2c_enable_irq(i2c);
s3c24xx_i2c_message_start(i2c, msgs);
+ if (i2c->quirks & QUIRK_POLL) {
+ ret = i2c->msg_idx;
+
+ if (ret != num)
+ dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
+
+ goto out;
+ }
+
timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
ret = i2c->msg_idx;
@@ -693,7 +760,11 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
s3c24xx_i2c_wait_idle(i2c);
+ s3c24xx_i2c_disable_bus(i2c);
+
out:
+ i2c->state = STATE_IDLE;
+
return ret;
}
@@ -820,6 +891,9 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
if (div1 == 512)
iiccon |= S3C2410_IICCON_TXDIV_512;
+ if (i2c->quirks & QUIRK_POLL)
+ iiccon |= S3C2410_IICCON_SCALE(2);
+
writel(iiccon, i2c->regs + S3C2410_IICCON);
if (i2c->quirks & QUIRK_S3C2440) {
@@ -842,7 +916,7 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
return 0;
}
-#ifdef CONFIG_CPU_FREQ
+#if defined(CONFIG_ARM_S3C24XX_CPUFREQ)
#define freq_to_i2c(_n) container_of(_n, struct s3c24xx_i2c, freq_transition)
@@ -959,7 +1033,6 @@ static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c)
static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
{
- unsigned long iicon = S3C2410_IICCON_IRQEN | S3C2410_IICCON_ACKEN;
struct s3c2410_platform_i2c *pdata;
unsigned int freq;
@@ -973,12 +1046,12 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
- writel(iicon, i2c->regs + S3C2410_IICCON);
+ writel(0, i2c->regs + S3C2410_IICCON);
+ writel(0, i2c->regs + S3C2410_IICSTAT);
/* we need to work out the divisors for the clock... */
if (s3c24xx_i2c_clockrate(i2c, &freq) != 0) {
- writel(0, i2c->regs + S3C2410_IICCON);
dev_err(i2c->dev, "cannot meet bus frequency required\n");
return -EINVAL;
}
@@ -986,7 +1059,8 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
/* todo - check that the i2c lines aren't being dragged anywhere */
dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq);
- dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon);
+ dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02x\n",
+ readl(i2c->regs + S3C2410_IICCON));
return 0;
}
@@ -1040,16 +1114,12 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
}
i2c = devm_kzalloc(&pdev->dev, sizeof(struct s3c24xx_i2c), GFP_KERNEL);
- if (!i2c) {
- dev_err(&pdev->dev, "no memory for state\n");
+ if (!i2c)
return -ENOMEM;
- }
i2c->pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
- if (!i2c->pdata) {
- dev_err(&pdev->dev, "no memory for platform data\n");
+ if (!i2c->pdata)
return -ENOMEM;
- }
i2c->quirks = s3c24xx_get_device_quirks(pdev);
if (pdata)
@@ -1061,7 +1131,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
i2c->adap.owner = THIS_MODULE;
i2c->adap.algo = &s3c24xx_i2c_algorithm;
i2c->adap.retries = 2;
- i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+ i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLASS_DEPRECATED;
i2c->tx_setup = 50;
init_waitqueue_head(&i2c->wait);
@@ -1117,18 +1187,20 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
* ensure no current IRQs pending
*/
- i2c->irq = ret = platform_get_irq(pdev, 0);
- if (ret <= 0) {
- dev_err(&pdev->dev, "cannot find IRQ\n");
- return ret;
- }
+ if (!(i2c->quirks & QUIRK_POLL)) {
+ i2c->irq = ret = platform_get_irq(pdev, 0);
+ if (ret <= 0) {
+ dev_err(&pdev->dev, "cannot find IRQ\n");
+ return ret;
+ }
ret = devm_request_irq(&pdev->dev, i2c->irq, s3c24xx_i2c_irq, 0,
- dev_name(&pdev->dev), i2c);
+ dev_name(&pdev->dev), i2c);
- if (ret != 0) {
- dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
- return ret;
+ if (ret != 0) {
+ dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
+ return ret;
+ }
}
ret = s3c24xx_i2c_register_cpufreq(i2c);
@@ -1178,8 +1250,6 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
i2c_del_adapter(&i2c->adap);
- clk_disable_unprepare(i2c->clk);
-
if (pdev->dev.of_node && IS_ERR(i2c->pctrl))
s3c24xx_i2c_dt_gpio_free(i2c);
@@ -1202,10 +1272,10 @@ static int s3c24xx_i2c_resume(struct device *dev)
struct platform_device *pdev = to_platform_device(dev);
struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
- i2c->suspended = 0;
clk_prepare_enable(i2c->clk);
s3c24xx_i2c_init(i2c);
clk_disable_unprepare(i2c->clk);
+ i2c->suspended = 0;
return 0;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-03 23:45:12 +0000