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Subject[PATCH 2/2 v4] i2c: exynos5: configure fifo_depth based on HSI2C module variant
Date
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.naveen@samsung.com>
[For finding out the difference and initial contribution]
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
---
changes since v3:
use variant struct to handle the fifo depths

drivers/i2c/busses/i2c-exynos5.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 12730d1..5c875c0 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -76,12 +76,6 @@
#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)

@@ -455,7 +449,7 @@ 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->variant->fifo_depth - fifo_level;
if (len > (i2c->msg->len - i2c->msg_ptr))
len = i2c->msg->len - i2c->msg_ptr;

@@ -523,6 +517,7 @@ 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);
@@ -533,13 +528,19 @@ 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->variant->fifo_depth) ?
+ (i2c->variant->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->variant->fifo_depth) ?
+ (i2c->variant->fifo_depth * 1/4) : i2c->msg->len;
+ fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl);
+
int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
}

@@ -731,6 +732,8 @@ static int exynos5_i2c_probe(struct platform_device *pdev)
if (ret)
goto err_clk;

+ i2c->variant = exynos5_i2c_get_variant(pdev);
+
exynos5_i2c_reset(i2c);

ret = i2c_add_adapter(&i2c->adap);
--
1.7.9.5


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