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soundwire: qcom: wait for fifo space to be available before read/write

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If we write registers very fast we can endup in a situation where some
of the writes will be dropped without any notice.

So wait for the fifo space to be available before reading/writing the
soundwire registers.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210401090058.24041-1-srinivas.kandagatla@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Srinivas Kandagatla 2021-04-01 10:00:58 +01:00 committed by Vinod Koul
parent eb5a909441
commit a661308c34
1 changed files with 66 additions and 0 deletions
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66
drivers/soundwire/qcom.c
View file

@ -24,6 +24,8 @@
#define SWRM_COMP_CFG_IRQ_LEVEL_OR_PULSE_MSK BIT(1)
#define SWRM_COMP_CFG_ENABLE_MSK BIT(0)
#define SWRM_COMP_PARAMS 0x100
#define SWRM_COMP_PARAMS_WR_FIFO_DEPTH GENMASK(14, 10)
#define SWRM_COMP_PARAMS_RD_FIFO_DEPTH GENMASK(19, 15)
#define SWRM_COMP_PARAMS_DOUT_PORTS_MASK GENMASK(4, 0)
#define SWRM_COMP_PARAMS_DIN_PORTS_MASK GENMASK(9, 5)
#define SWRM_INTERRUPT_STATUS 0x200
@ -51,6 +53,8 @@
#define SWRM_CMD_FIFO_CMD 0x308
#define SWRM_CMD_FIFO_FLUSH 0x1
#define SWRM_CMD_FIFO_STATUS 0x30C
#define SWRM_RD_CMD_FIFO_CNT_MASK GENMASK(20, 16)
#define SWRM_WR_CMD_FIFO_CNT_MASK GENMASK(12, 8)
#define SWRM_CMD_FIFO_CFG_ADDR 0x314
#define SWRM_CONTINUE_EXEC_ON_CMD_IGNORE BIT(31)
#define SWRM_RD_WR_CMD_RETRIES 0x7
@ -104,6 +108,7 @@
#define SWR_BROADCAST_CMD_ID 0x0F
#define SWR_MAX_CMD_ID 14
#define MAX_FIFO_RD_RETRY 3
#define SWR_OVERFLOW_RETRY_COUNT 30
struct qcom_swrm_port_config {
u8 si;
@ -147,6 +152,8 @@ struct qcom_swrm_ctrl {
int (*reg_read)(struct qcom_swrm_ctrl *ctrl, int reg, u32 *val);
int (*reg_write)(struct qcom_swrm_ctrl *ctrl, int reg, int val);
u32 slave_status;
u32 wr_fifo_depth;
u32 rd_fifo_depth;
};
struct qcom_swrm_data {
@ -238,6 +245,55 @@ static u32 swrm_get_packed_reg_val(u8 *cmd_id, u8 cmd_data,
return val;
}
static int swrm_wait_for_rd_fifo_avail(struct qcom_swrm_ctrl *swrm)
{
u32 fifo_outstanding_data, value;
int fifo_retry_count = SWR_OVERFLOW_RETRY_COUNT;
do {
/* Check for fifo underflow during read */
swrm->reg_read(swrm, SWRM_CMD_FIFO_STATUS, &value);
fifo_outstanding_data = FIELD_GET(SWRM_RD_CMD_FIFO_CNT_MASK, value);
/* Check if read data is available in read fifo */
if (fifo_outstanding_data > 0)
return 0;
usleep_range(500, 510);
} while (fifo_retry_count--);
if (fifo_outstanding_data == 0) {
dev_err_ratelimited(swrm->dev, "%s err read underflow\n", __func__);
return -EIO;
}
return 0;
}
static int swrm_wait_for_wr_fifo_avail(struct qcom_swrm_ctrl *swrm)
{
u32 fifo_outstanding_cmds, value;
int fifo_retry_count = SWR_OVERFLOW_RETRY_COUNT;
do {
/* Check for fifo overflow during write */
swrm->reg_read(swrm, SWRM_CMD_FIFO_STATUS, &value);
fifo_outstanding_cmds = FIELD_GET(SWRM_WR_CMD_FIFO_CNT_MASK, value);
/* Check for space in write fifo before writing */
if (fifo_outstanding_cmds < swrm->wr_fifo_depth)
return 0;
usleep_range(500, 510);
} while (fifo_retry_count--);
if (fifo_outstanding_cmds == swrm->wr_fifo_depth) {
dev_err_ratelimited(swrm->dev, "%s err write overflow\n", __func__);
return -EIO;
}
return 0;
}
static int qcom_swrm_cmd_fifo_wr_cmd(struct qcom_swrm_ctrl *swrm, u8 cmd_data,
u8 dev_addr, u16 reg_addr)
@ -256,6 +312,9 @@ static int qcom_swrm_cmd_fifo_wr_cmd(struct qcom_swrm_ctrl *swrm, u8 cmd_data,
dev_addr, reg_addr);
}
if (swrm_wait_for_wr_fifo_avail(swrm))
return SDW_CMD_FAIL_OTHER;
/* Its assumed that write is okay as we do not get any status back */
swrm->reg_write(swrm, SWRM_CMD_FIFO_WR_CMD, val);
@ -295,6 +354,9 @@ static int qcom_swrm_cmd_fifo_rd_cmd(struct qcom_swrm_ctrl *swrm,
/* wait for FIFO RD CMD complete to avoid overflow */
usleep_range(250, 255);
if (swrm_wait_for_rd_fifo_avail(swrm))
return SDW_CMD_FAIL_OTHER;
do {
swrm->reg_read(swrm, SWRM_CMD_FIFO_RD_FIFO_ADDR, &cmd_data);
rval[0] = cmd_data & 0xFF;
@ -586,6 +648,10 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
SWRM_INTERRUPT_STATUS_RMSK);
}
ctrl->slave_status = 0;
ctrl->reg_read(ctrl, SWRM_COMP_PARAMS, &val);
ctrl->rd_fifo_depth = FIELD_GET(SWRM_COMP_PARAMS_RD_FIFO_DEPTH, val);
ctrl->wr_fifo_depth = FIELD_GET(SWRM_COMP_PARAMS_WR_FIFO_DEPTH, val);
return 0;
}