Thread (16 messages) 16 messages, 3 authors, 2018-07-20

Re: [PATCH 2/5] i2c: designware: allow IP specific sda_hold_time

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2018-07-17 14:33:44
Also in: linux-i2c, linux-mips, lkml

On Tue, 2018-07-17 at 13:48 +0200, Alexandre Belloni wrote:
Because some old designware IPs were not supporting setting an SDA
hold
time, vendors developed their own solution. Add a way for the final
driver
to provide its own SDA hold time handling.
Thanks for information you provided. See my comment below.
After addressing it, 

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
quoted hunk ↗ jump to hunk
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/i2c/busses/i2c-designware-common.c | 6 ++++++
 drivers/i2c/busses/i2c-designware-core.h   | 1 +
 2 files changed, 7 insertions(+)
diff --git a/drivers/i2c/busses/i2c-designware-common.c
b/drivers/i2c/busses/i2c-designware-common.c
index 9afc3e075b33..545b69d6be3c 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -297,6 +297,12 @@ void i2c_dw_set_sda_hold_time(struct dw_i2c_dev
*dev)
 {
 	u32 reg;
 
+	if (dev->set_sda_hold_time) {
+		dev->set_sda_hold_time(dev);
+
+		return;
+	}
I would rather inject this, for now (*), into if-else-if ladder, i.e.

if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
 ...
} else if (dev->set_sda_hold_time) { // <<<
 ...
} else if (dev->sda_hold_time) {
 ...

(*) Since your IP is of v1.10a I don't believe any new version of IP
would shadow existing DW IP registers, thus version check is okay to
have first in my opinion.
quoted hunk ↗ jump to hunk
+
 	/* Configure SDA Hold Time if required. */
 	reg = dw_readl(dev, DW_IC_COMP_VERSION);
 	if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
diff --git a/drivers/i2c/busses/i2c-designware-core.h
b/drivers/i2c/busses/i2c-designware-core.h
index bc43fb9ac1cf..b2778b6d8aca 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -283,6 +283,7 @@ struct dw_i2c_dev {
 	void			(*disable)(struct dw_i2c_dev
*dev);
 	void			(*disable_int)(struct dw_i2c_dev
*dev);
 	int			(*init)(struct dw_i2c_dev *dev);
+	int			(*set_sda_hold_time)(struct
dw_i2c_dev *dev);
 	int			mode;
 	struct i2c_bus_recovery_info rinfo;
 };
-- 
Andy Shevchenko [off-list ref]
Intel Finland Oy
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