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input: qcom-hv-haptics: discard 1-byte FIFO write for HAP520

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For haptics module with HAP520 HW revision, the HW would only read 1
valid byte in every 4 bytes if the 1-byte FIFO write clashes with the
FIFO read operation. To avoid this, don't use 1-byte write but just
pad zeros at end of the pattern to keep the samples 4-byte aligned
and always use 4-byte write for FIFO programming.

Change-Id: I3ebde0fe7378c0dcffb5c51e15e6ffaae5af3e29
Signed-off-by: Fenglin Wu <quic_fenglinw@quicinc.com>
This commit is contained in:
Fenglin Wu 2022-03-21 15:07:59 +08:00 committed by David Collins
parent 7644b7452c
commit 83af7dff89
1 changed files with 36 additions and 13 deletions
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49
drivers/input/misc/qcom-hv-haptics.c
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@ -1601,6 +1601,10 @@ static int haptics_update_memory_data(struct haptics_chip *chip,
{
int rc, count, i;
u32 left;
u8 tmp[HAP_PTN_FIFO_DIN_NUM] = {0};
if (!length)
return 0;
count = length / HAP_PTN_FIFO_DIN_NUM;
for (i = 0; i < count; i++) {
@ -1618,6 +1622,24 @@ static int haptics_update_memory_data(struct haptics_chip *chip,
left = length % HAP_PTN_FIFO_DIN_NUM;
if (left) {
/*
* In HAP520 module, when 1-byte FIFO write clashes
* with the HW FIFO read operation, the HW will only read
* 1 valid byte in every 4 bytes FIFO samples. So avoid
* this by keeping the samples 4-byte aligned and always
* use 4-byte write for HAP520 module.
*/
if (chip->hw_type == HAP520) {
memcpy(tmp, data, left);
rc = haptics_write(chip, chip->ptn_addr_base,
HAP_PTN_FIFO_DIN_0_REG, tmp,
HAP_PTN_FIFO_DIN_NUM);
if (rc < 0)
dev_err(chip->dev, "write FIFO_DIN failed, rc=%d\n", rc);
return rc;
}
for (i = 0; i < left; i++) {
rc = haptics_write(chip, chip->ptn_addr_base,
HAP_PTN_FIFO_DIN_1B_REG,
@ -1894,6 +1916,10 @@ static int haptics_set_fifo(struct haptics_chip *chip, struct fifo_cfg *fifo)
return available;
num = min_t(u32, available, num);
/* Keep the FIFO programming 4-byte aligned if FIFO refilling is needed */
if ((num < fifo->num_s) && (num % HAP_PTN_FIFO_DIN_NUM))
num = round_down(num, HAP_PTN_FIFO_DIN_NUM);
rc = haptics_update_fifo_samples(chip, fifo->samples, num, false);
if (rc < 0) {
dev_err(chip->dev, "write FIFO samples failed, rc=%d\n", rc);
@ -3032,21 +3058,18 @@ static irqreturn_t fifo_empty_irq_handler(int irq, void *data)
if (num < 0)
goto unlock;
/*
* If 1-byte write is done before a 4-byte write, the hardware
* would insert zeros in between to keep the FIFO samples
* 4-byte aligned, and the inserted 0 values would cause HW
* stop driving hence spurs will be seen on the haptics output.
* So only use 1-byte write at the end of FIFO streaming.
*/
if (samples_left <= num)
num = samples_left;
else if (num % HAP_PTN_FIFO_DIN_NUM)
num -= (num % HAP_PTN_FIFO_DIN_NUM);
samples = fifo->samples + status->samples_written;
/* Write more pattern data into FIFO memory. */
/*
* Always use 4-byte burst write in the middle of FIFO programming to
* avoid HW padding zeros during 1-byte write which would cause the HW
* stop driving for the unexpected padding zeros.
*/
if (num < samples_left)
num = round_down(num, HAP_PTN_FIFO_DIN_NUM);
else
num = samples_left;
rc = haptics_update_fifo_samples(chip, samples, num, true);
if (rc < 0) {
dev_err(chip->dev, "Update FIFO samples failed, rc=%d\n",