fifo_depth of the HSI2C is not constant
Exynos5420 and Exynos5250 supports fifo_depth of 64bytes
Exynos5260 supports fifo_depth of 16bytes
This patch configures the fifo_depth based on HSI2C modules version.
Signed-off-by: Naveen Krishna Chatradhi <ich.nav...@samsung.com>
[For finding out the difference and initial contribution]
Signed-off-by: Pankaj Dubey <pankaj.du...@samsung.com>
---
Changes since v1:
Added missed out Signed-off-by line for initial contribution
Also rebasing on linux-i2c for-next
drivers/i2c/busses/i2c-exynos5.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 497ff91..a3fdcd8 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -77,12 +77,6 @@
#define HSI2C_RXFIFO_TRIGGER_LEVEL(x) ((x) << 4)
#define HSI2C_TXFIFO_TRIGGER_LEVEL(x) ((x) << 16)
-/* As per user manual FIFO max depth is 64bytes */
-#define HSI2C_FIFO_MAX 0x40
-/* default trigger levels for Tx and Rx FIFOs */
-#define HSI2C_DEF_TXFIFO_LVL (HSI2C_FIFO_MAX - 0x30)
-#define HSI2C_DEF_RXFIFO_LVL (HSI2C_FIFO_MAX - 0x10)
-
/* I2C_TRAILING_CTL Register bits */
#define HSI2C_TRAILING_COUNT (0xf)
@@ -187,6 +181,9 @@ struct exynos5_i2c {
/* Version of HS-I2C Hardware */
unsigned int version;
+
+ /* FIFO depth */
+ unsigned int fifo_depth;
};
enum hsi2c_version {
@@ -437,7 +434,7 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
fifo_level = HSI2C_TX_FIFO_LVL(fifo_status);
- len = HSI2C_FIFO_MAX - fifo_level;
+ len = i2c->fifo_depth - fifo_level;
if (len > (i2c->msg->len - i2c->msg_ptr))
len = i2c->msg->len - i2c->msg_ptr;
@@ -505,6 +502,7 @@ static void exynos5_i2c_message_start(struct exynos5_i2c
*i2c, int stop)
u32 i2c_auto_conf = 0;
u32 fifo_ctl;
unsigned long flags;
+ unsigned short trig_lvl;
i2c_ctl = readl(i2c->regs + HSI2C_CTL);
i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON);
@@ -515,13 +513,19 @@ static void exynos5_i2c_message_start(struct exynos5_i2c
*i2c, int stop)
i2c_auto_conf = HSI2C_READ_WRITE;
- fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(HSI2C_DEF_TXFIFO_LVL);
+ trig_lvl = (i2c->msg->len > i2c->fifo_depth) ?
+ (i2c->fifo_depth * 3/4) : i2c->msg->len;
+ fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(trig_lvl);
+
int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN |
HSI2C_INT_TRAILING_EN);
} else {
i2c_ctl |= HSI2C_TXCHON;
- fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(HSI2C_DEF_RXFIFO_LVL);
+ trig_lvl = (i2c->msg->len > i2c->fifo_depth) ?
+ (i2c->fifo_depth * 1/4) : i2c->msg->len;
+ fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl);
+
int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
}
@@ -716,10 +720,13 @@ static int exynos5_i2c_probe(struct platform_device *pdev)
i2c->version = exynos5_i2c_get_version(pdev);
/* The HS-I2C core on Exynos5260 needs a reset to start with */
- if (i2c->version == EXYNOS_5260)
+ if (i2c->version == EXYNOS_5260) {
+ i2c->fifo_depth = 16;
exynos5_i2c_reset(i2c);
- else
+ } else {
+ i2c->fifo_depth = 64;
exynos5_i2c_init(i2c);
+ }
ret = i2c_add_adapter(&i2c->adap);
if (ret < 0) {
--
1.7.10.4
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