In the existing code every soundwire register read and register write are kinda blocked. Each of these are using a special command id that generates interrupt after it successfully finishes. This is really overhead, limiting and not really necessary unless we are doing something special.
We can simply read/write the fifo that should also give exactly what we need! This will also allow to read/write registers in interrupt context, which was not possible with the special command approach.
Signed-off-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org --- drivers/soundwire/qcom.c | 148 +++++++++++++++++++++++++-------------- 1 file changed, 96 insertions(+), 52 deletions(-)
diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c index 83df15d83935..d61b204dc284 100644 --- a/drivers/soundwire/qcom.c +++ b/drivers/soundwire/qcom.c @@ -78,13 +78,15 @@ #define SWRM_SPECIAL_CMD_ID 0xF #define MAX_FREQ_NUM 1 #define TIMEOUT_MS (2 * HZ) -#define QCOM_SWRM_MAX_RD_LEN 0xf +#define QCOM_SWRM_MAX_RD_LEN 0x1 #define QCOM_SDW_MAX_PORTS 14 #define DEFAULT_CLK_FREQ 9600000 #define SWRM_MAX_DAIS 0xF #define SWR_INVALID_PARAM 0xFF #define SWR_HSTOP_MAX_VAL 0xF #define SWR_HSTART_MIN_VAL 0x0 +#define SWR_BROADCAST_CMD_ID 0x0F +#define MAX_FIFO_RD_FAIL_RETRY 3
struct qcom_swrm_port_config { u8 si; @@ -104,11 +106,13 @@ struct qcom_swrm_ctrl { struct regmap *regmap; void __iomem *mmio; struct completion *comp; + struct completion broadcast; struct work_struct slave_work; /* read/write lock */ spinlock_t comp_lock; /* Port alloc/free lock */ struct mutex port_lock; + struct mutex io_lock; struct clk *hclk; u8 wr_cmd_id; u8 rd_cmd_id; @@ -122,6 +126,8 @@ struct qcom_swrm_ctrl { int rows_index; unsigned long dout_port_mask; unsigned long din_port_mask; + u8 rcmd_id; + u8 wcmd_id; struct qcom_swrm_port_config pconfig[QCOM_SDW_MAX_PORTS]; struct sdw_stream_runtime *sruntime[SWRM_MAX_DAIS]; enum sdw_slave_status status[SDW_MAX_DEVICES]; @@ -200,75 +206,111 @@ static int qcom_swrm_cpu_reg_write(struct qcom_swrm_ctrl *ctrl, int reg, return SDW_CMD_OK; }
-static int qcom_swrm_cmd_fifo_wr_cmd(struct qcom_swrm_ctrl *ctrl, u8 cmd_data, - u8 dev_addr, u16 reg_addr) +static u32 swrm_get_packed_reg_val(u8 *cmd_id, u8 cmd_data, + u8 dev_addr, u16 reg_addr) { - DECLARE_COMPLETION_ONSTACK(comp); - unsigned long flags; u32 val; - int ret; - - spin_lock_irqsave(&ctrl->comp_lock, flags); - ctrl->comp = ∁ - spin_unlock_irqrestore(&ctrl->comp_lock, flags); - val = SWRM_REG_VAL_PACK(cmd_data, dev_addr, - SWRM_SPECIAL_CMD_ID, reg_addr); - ret = ctrl->reg_write(ctrl, SWRM_CMD_FIFO_WR_CMD, val); - if (ret) - goto err; - - ret = wait_for_completion_timeout(ctrl->comp, - msecs_to_jiffies(TIMEOUT_MS)); + u8 id = *cmd_id;
- if (!ret) - ret = SDW_CMD_IGNORED; - else - ret = SDW_CMD_OK; -err: - spin_lock_irqsave(&ctrl->comp_lock, flags); - ctrl->comp = NULL; - spin_unlock_irqrestore(&ctrl->comp_lock, flags); + if (id != SWR_BROADCAST_CMD_ID) { + if (id < 14) + id += 1; + else + id = 0; + *cmd_id = id; + } + val = SWRM_REG_VAL_PACK(cmd_data, dev_addr, id, reg_addr);
- return ret; + return val; }
-static int qcom_swrm_cmd_fifo_rd_cmd(struct qcom_swrm_ctrl *ctrl, - u8 dev_addr, u16 reg_addr, - u32 len, u8 *rval) + +static int qcom_swrm_cmd_fifo_wr_cmd(struct qcom_swrm_ctrl *swrm, u8 cmd_data, + u8 dev_addr, u16 reg_addr) { - int i, ret; + u32 val; - DECLARE_COMPLETION_ONSTACK(comp); - unsigned long flags; + int ret = 0; + u8 cmd_id = 0x0; + + mutex_lock(&swrm->io_lock); + if (dev_addr == SDW_BROADCAST_DEV_NUM) { + cmd_id = SWR_BROADCAST_CMD_ID; + val = swrm_get_packed_reg_val(&cmd_id, cmd_data, + dev_addr, reg_addr); + } else { + val = swrm_get_packed_reg_val(&swrm->wcmd_id, cmd_data, + dev_addr, reg_addr); + }
- spin_lock_irqsave(&ctrl->comp_lock, flags); - ctrl->comp = ∁ - spin_unlock_irqrestore(&ctrl->comp_lock, flags); + swrm->reg_write(swrm, SWRM_CMD_FIFO_WR_CMD, val);
- val = SWRM_REG_VAL_PACK(len, dev_addr, SWRM_SPECIAL_CMD_ID, reg_addr); - ret = ctrl->reg_write(ctrl, SWRM_CMD_FIFO_RD_CMD, val); - if (ret) - goto err; + /* version 1.3 or less */ + if (swrm->version_major == 1 && swrm->version_minor <= 3) + usleep_range(150, 155);
- ret = wait_for_completion_timeout(ctrl->comp, - msecs_to_jiffies(TIMEOUT_MS)); + if (cmd_id == SWR_BROADCAST_CMD_ID) { + /* + * sleep for 10ms for MSM soundwire variant to allow broadcast + * command to complete. + */ + ret = wait_for_completion_timeout(&swrm->broadcast, (2 * HZ/10)); + if (!ret) + ret = SDW_CMD_IGNORED; + else + ret = SDW_CMD_OK;
- if (!ret) { - ret = SDW_CMD_IGNORED; - goto err; } else { ret = SDW_CMD_OK; } + mutex_unlock(&swrm->io_lock); + return ret; +}
- for (i = 0; i < len; i++) { - ctrl->reg_read(ctrl, SWRM_CMD_FIFO_RD_FIFO_ADDR, &val); - rval[i] = val & 0xFF; +static int qcom_swrm_cmd_fifo_rd_cmd(struct qcom_swrm_ctrl *swrm, + u8 dev_addr, u16 reg_addr, + u32 len, u8 *rval) +{ + u32 val; + u32 retry_attempt = 0; + u32 cmd_data; + int ret = SDW_CMD_OK; + + mutex_lock(&swrm->io_lock); + val = swrm_get_packed_reg_val(&swrm->rcmd_id, len, dev_addr, reg_addr); + + /* wait for FIFO RD to complete to avoid overflow */ + usleep_range(100, 105); + swrm->reg_write(swrm, SWRM_CMD_FIFO_RD_CMD, val); + /* wait for FIFO RD CMD complete to avoid overflow */ + usleep_range(250, 255); + +retry_read: + + swrm->reg_read(swrm, SWRM_CMD_FIFO_RD_FIFO_ADDR, &cmd_data); + rval[0] = cmd_data & 0xFF; + + if ((((cmd_data) & 0xF00) >> 8) != swrm->rcmd_id) { + if (retry_attempt < MAX_FIFO_RD_FAIL_RETRY) { + /* wait 500 us before retry on fifo read failure */ + usleep_range(500, 505); + if (retry_attempt == (MAX_FIFO_RD_FAIL_RETRY - 1)) { + swrm->reg_write(swrm, SWRM_CMD_FIFO_CMD, 0x1); + swrm->reg_write(swrm, SWRM_CMD_FIFO_RD_CMD, val); + } + retry_attempt++; + goto retry_read; + } else { + dev_err(swrm->dev, + "failed to read fifo: reg: 0x%x, \ + rcmd_id: 0x%x, dev_num: 0x%x, cmd_data: 0x%x\n", + reg_addr, swrm->rcmd_id, + dev_addr, cmd_data); + ret = SDW_CMD_IGNORED; + } }
-err: - spin_lock_irqsave(&ctrl->comp_lock, flags); - ctrl->comp = NULL; - spin_unlock_irqrestore(&ctrl->comp_lock, flags); + mutex_unlock(&swrm->io_lock);
return ret; } @@ -949,6 +991,8 @@ static int qcom_swrm_probe(struct platform_device *pdev) dev_set_drvdata(&pdev->dev, ctrl); spin_lock_init(&ctrl->comp_lock); mutex_init(&ctrl->port_lock); + mutex_init(&ctrl->io_lock); + init_completion(&ctrl->broadcast); INIT_WORK(&ctrl->slave_work, qcom_swrm_slave_wq);
ctrl->bus.ops = &qcom_swrm_ops;