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.
With previous approach number of interrupts generated after enumeration are around 130: $ cat /proc/interrupts | grep soundwire 21: 130 0 0 0 0 0 0 0 GICv3 234 Edge soundwire
after this patch they are just 3 interrupts $ cat /proc/interrupts | grep soundwire 21: 3 0 0 0 0 0 0 0 GICv3 234 Edge soundwire
This has significantly not only reduced interrupting CPU during enumeration but also during streaming!
Signed-off-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org --- drivers/soundwire/qcom.c | 178 ++++++++++++++++++++++----------------- 1 file changed, 99 insertions(+), 79 deletions(-)
diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c index 6a7c0acc8d89..e1cf821ea5e0 100644 --- a/drivers/soundwire/qcom.c +++ b/drivers/soundwire/qcom.c @@ -38,11 +38,13 @@ #define SWRM_CMD_FIFO_WR_CMD 0x300 #define SWRM_CMD_FIFO_RD_CMD 0x304 #define SWRM_CMD_FIFO_CMD 0x308 +#define SWRM_CMD_FIFO_FLUSH 0x1 #define SWRM_CMD_FIFO_STATUS 0x30C #define SWRM_CMD_FIFO_CFG_ADDR 0x314 #define SWRM_CONTINUE_EXEC_ON_CMD_IGNORE BIT(31) #define SWRM_RD_WR_CMD_RETRIES 0x7 #define SWRM_CMD_FIFO_RD_FIFO_ADDR 0x318 +#define SWRM_RD_FIFO_CMD_ID_MASK GENMASK(11, 8) #define SWRM_ENUMERATOR_CFG_ADDR 0x500 #define SWRM_MCP_FRAME_CTRL_BANK_ADDR(m) (0x101C + 0x40 * (m)) #define SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK GENMASK(2, 0) @@ -78,13 +80,16 @@ #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 SWR_MAX_CMD_ID 14 +#define MAX_FIFO_RD_RETRY 3
struct qcom_swrm_port_config { u8 si; @@ -103,10 +108,8 @@ struct qcom_swrm_ctrl { struct device *dev; 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 clk *hclk; @@ -120,6 +123,8 @@ 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]; @@ -198,77 +203,105 @@ 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 < SWR_MAX_CMD_ID) + 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;
- spin_lock_irqsave(&ctrl->comp_lock, flags); - ctrl->comp = ∁ - spin_unlock_irqrestore(&ctrl->comp_lock, flags); + u32 val; + int ret = 0; + u8 cmd_id = 0x0;
- 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; + 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); + }
- ret = wait_for_completion_timeout(ctrl->comp, - msecs_to_jiffies(TIMEOUT_MS)); + swrm->reg_write(swrm, SWRM_CMD_FIFO_WR_CMD, val); + + /* version 1.3 or less */ + if (swrm->version <= 0x01030000) + usleep_range(150, 155); + + 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, + msecs_to_jiffies(TIMEOUT_MS)); + if (!ret) + ret = SDW_CMD_IGNORED; + else + ret = SDW_CMD_OK;
- if (!ret) { - ret = SDW_CMD_IGNORED; - goto err; } else { ret = SDW_CMD_OK; } + 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 cmd_data, cmd_id, val, retry_attempt = 0; + + 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); + + do { + swrm->reg_read(swrm, SWRM_CMD_FIFO_RD_FIFO_ADDR, &cmd_data); + rval[0] = cmd_data & 0xFF; + cmd_id = FIELD_GET(SWRM_RD_FIFO_CMD_ID_MASK, cmd_data); + + if (cmd_id != swrm->rcmd_id) { + if (retry_attempt < (MAX_FIFO_RD_RETRY - 1)) { + /* wait 500 us before retry on fifo read failure */ + usleep_range(500, 505); + swrm->reg_write(swrm, SWRM_CMD_FIFO_CMD, + SWRM_CMD_FIFO_FLUSH); + swrm->reg_write(swrm, SWRM_CMD_FIFO_RD_CMD, val); + } + retry_attempt++; + } else { + return SDW_CMD_OK; + }
-err: - spin_lock_irqsave(&ctrl->comp_lock, flags); - ctrl->comp = NULL; - spin_unlock_irqrestore(&ctrl->comp_lock, flags); + } while (retry_attempt < MAX_FIFO_RD_RETRY);
- return ret; + 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); + + return SDW_CMD_IGNORED; }
static void qcom_swrm_get_device_status(struct qcom_swrm_ctrl *ctrl) @@ -291,7 +324,6 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id) { struct qcom_swrm_ctrl *ctrl = dev_id; u32 sts, value; - unsigned long flags;
ctrl->reg_read(ctrl, SWRM_INTERRUPT_STATUS, &sts);
@@ -304,8 +336,10 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id) }
if ((sts & SWRM_INTERRUPT_STATUS_NEW_SLAVE_ATTACHED) || - sts & SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS) - schedule_work(&ctrl->slave_work); + sts & SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS) { + qcom_swrm_get_device_status(ctrl); + sdw_handle_slave_status(&ctrl->bus, ctrl->status); + }
/** * clear the interrupt before complete() is called, as complete can @@ -314,15 +348,12 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id) */ ctrl->reg_write(ctrl, SWRM_INTERRUPT_CLEAR, sts);
- if (sts & SWRM_INTERRUPT_STATUS_SPECIAL_CMD_ID_FINISHED) { - spin_lock_irqsave(&ctrl->comp_lock, flags); - if (ctrl->comp) - complete(ctrl->comp); - spin_unlock_irqrestore(&ctrl->comp_lock, flags); - } + if (sts & SWRM_INTERRUPT_STATUS_SPECIAL_CMD_ID_FINISHED) + complete(&ctrl->broadcast);
return IRQ_HANDLED; } + static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl) { u32 val; @@ -570,16 +601,6 @@ static u32 qcom_swrm_freq_tbl[MAX_FREQ_NUM] = { DEFAULT_CLK_FREQ, };
-static void qcom_swrm_slave_wq(struct work_struct *work) -{ - struct qcom_swrm_ctrl *ctrl = - container_of(work, struct qcom_swrm_ctrl, slave_work); - - qcom_swrm_get_device_status(ctrl); - sdw_handle_slave_status(&ctrl->bus, ctrl->status); -} - - static void qcom_swrm_stream_free_ports(struct qcom_swrm_ctrl *ctrl, struct sdw_stream_runtime *stream) { @@ -936,9 +957,8 @@ static int qcom_swrm_probe(struct platform_device *pdev)
ctrl->dev = dev; dev_set_drvdata(&pdev->dev, ctrl); - spin_lock_init(&ctrl->comp_lock); mutex_init(&ctrl->port_lock); - INIT_WORK(&ctrl->slave_work, qcom_swrm_slave_wq); + init_completion(&ctrl->broadcast);
ctrl->bus.ops = &qcom_swrm_ops; ctrl->bus.port_ops = &qcom_swrm_port_ops;