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| author | Bastian Stender <bst@pengutronix.de> | 2017-02-23 17:34:49 +0100 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2017-03-02 14:03:43 +0100 |
| commit | 8d38b5205c4b2d2a7b437898119d0240e6e3ebfb (patch) | |
| tree | 67c731aff439895da6b9fe68ddc4ca84b75d6035 /drivers/i2c | |
| parent | 222078a38c4d918a3c1d1ddb977c31898f3f3aeb (diff) | |
| download | barebox-8d38b5205c4b2d2a7b437898119d0240e6e3ebfb.tar.gz barebox-8d38b5205c4b2d2a7b437898119d0240e6e3ebfb.tar.xz | |
i2c: mv64xxx: add software delays
As stated in Marvell's Functional Specifications in MV-S107021-U0 Rev. A
on page 420 ff. software delays are needed. "SW delay represent a delay
of at least 2 internal clock cycles". These delays are hereby
implemented.
The original kernel driver compensates the needed software delays with
the time the interrupts take.
Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mv64xxx.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c index 9b9e6c953f..45d5a2b6dc 100644 --- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -270,6 +270,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) } /* FALLTHRU */ case STATUS_MAST_RD_DATA_ACK: /* 0x50 */ + udelay(2); if (status != STATUS_MAST_RD_DATA_ACK) drv_data->action = ACTION_CONTINUE; else { @@ -280,6 +281,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status) if (drv_data->bytes_left == 1) drv_data->cntl_bits &= ~REG_CONTROL_ACK; + udelay(2); break; case STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */ @@ -318,6 +320,8 @@ static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data) mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs); mv64xxx_write(drv_data, drv_data->cntl_bits | REG_CONTROL_START, drv_data->reg_offsets.control); + + udelay(2); } static void @@ -333,7 +337,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) mv64xxx_i2c_send_start(drv_data); if (drv_data->errata_delay) - udelay(5); + udelay(3); /* * We're never at the start of the message here, and by this @@ -349,6 +353,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) break; case ACTION_SEND_ADDR_1: + udelay(2); mv64xxx_write(drv_data, drv_data->addr1, drv_data->reg_offsets.data); mv64xxx_write(drv_data, drv_data->cntl_bits, @@ -360,9 +365,11 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) drv_data->reg_offsets.data); mv64xxx_write(drv_data, drv_data->cntl_bits, drv_data->reg_offsets.control); + udelay(2); break; case ACTION_SEND_DATA: + udelay(2); mv64xxx_write(drv_data, drv_data->msg->buf[drv_data->byte_posn++], drv_data->reg_offsets.data); mv64xxx_write(drv_data, drv_data->cntl_bits, @@ -383,8 +390,9 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) mv64xxx_write(drv_data, drv_data->cntl_bits | REG_CONTROL_STOP, drv_data->reg_offsets.control); drv_data->block = false; + udelay(2); if (drv_data->errata_delay) - udelay(5); + udelay(3); break; |