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i2c: mvtwsi: Fix mvtwsi not working on sun6i and newer sunxi SoCs

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On sun6i and newer IFLG is a write-clear bit which is cleared by writing 1,
rather then a normal r/w bit which is cleared by writing 0.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

applied with fixing 3 checkpatch warnings
in drivers/i2c/mvtwsi.c:
WARNING: line over 80 characters
ERROR: code indent should use tabs where possible
WARNING: please, no spaces at the start of a line

Signed-off-by: Heiko Schocher <hs@denx.de>
This commit is contained in:
Hans de Goede 2016-01-14 14:06:25 +01:00 committed by Heiko Schocher
parent 57e5ecaf75
commit 904dfbfd67
1 changed files with 16 additions and 4 deletions
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20
drivers/i2c/mvtwsi.c
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@ -72,6 +72,17 @@ struct mvtwsi_registers {
#define MVTWSI_CONTROL_TWSIEN 0x00000040
#define MVTWSI_CONTROL_INTEN 0x00000080
/*
* On sun6i and newer IFLG is a write-clear bit which is cleared by writing 1,
* on other platforms it is a normal r/w bit which is cleared by writing 0.
*/
#ifdef CONFIG_SUNXI_GEN_SUN6I
#define MVTWSI_CONTROL_CLEAR_IFLG 0x00000008
#else
#define MVTWSI_CONTROL_CLEAR_IFLG 0x00000000
#endif
/*
* Status register values -- only those expected in normal master
* operation on non-10-bit-address devices; whatever status we don't
@ -189,7 +200,8 @@ static int twsi_start(struct i2c_adapter *adap, int expected_status)
/* globally set TWSIEN in case it was not */
twsi_control_flags |= MVTWSI_CONTROL_TWSIEN;
/* assert START */
writel(twsi_control_flags | MVTWSI_CONTROL_START, &twsi->control);
twsi_control_flags |= MVTWSI_CONTROL_START | MVTWSI_CONTROL_CLEAR_IFLG;
writel(twsi_control_flags, &twsi->control);
/* wait for controller to process START */
return twsi_wait(adap, expected_status);
}
@ -204,7 +216,7 @@ static int twsi_send(struct i2c_adapter *adap, u8 byte, int expected_status)
/* put byte in data register for sending */
writel(byte, &twsi->data);
/* clear any pending interrupt -- that'll cause sending */
writel(twsi_control_flags, &twsi->control);
writel(twsi_control_flags | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);
/* wait for controller to receive byte and check ACK */
return twsi_wait(adap, expected_status);
}
@ -224,7 +236,7 @@ static int twsi_recv(struct i2c_adapter *adap, u8 *byte)
else
expected_status = MVTWSI_STATUS_DATA_R_NAK;
/* acknowledge *previous state* and launch receive */
writel(twsi_control_flags, &twsi->control);
writel(twsi_control_flags | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);
/* wait for controller to receive byte and assert ACK or NAK */
status = twsi_wait(adap, expected_status);
/* if we did receive expected byte then store it */
@ -246,7 +258,7 @@ static int twsi_stop(struct i2c_adapter *adap, int status)
/* assert STOP */
control = MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_STOP;
writel(control, &twsi->control);
writel(control | MVTWSI_CONTROL_CLEAR_IFLG, &twsi->control);
/* wait for IDLE; IFLG won't rise so twsi_wait() is no use. */
do {
stop_status = readl(&twsi->status);