> +static void amd_enable_sdw_pads(struct amd_sdw_manager *amd_manager) > +{ > + u32 sw_pad_pulldown_val; > + u32 val = 0; useless init > + > + mutex_lock(amd_manager->sdw_lock); > + val = acp_reg_readl(amd_manager->acp_mmio + ACP_SW_PAD_KEEPER_EN); > + val |= amd_manager->reg_mask->sw_pad_enable_mask; > + acp_reg_writel(val, amd_manager->acp_mmio + ACP_SW_PAD_KEEPER_EN); > + usleep_range(1000, 1500); > + > + sw_pad_pulldown_val = acp_reg_readl(amd_manager->acp_mmio + ACP_PAD_PULLDOWN_CTRL); > + sw_pad_pulldown_val &= amd_manager->reg_mask->sw_pad_pulldown_mask; > + acp_reg_writel(sw_pad_pulldown_val, amd_manager->acp_mmio + ACP_PAD_PULLDOWN_CTRL); > + mutex_unlock(amd_manager->sdw_lock); > +} > + > +static int amd_init_sdw_manager(struct amd_sdw_manager *amd_manager) > +{ > + u32 val = 0; useless init > + u32 timeout = 0; > + u32 retry_count = 0; > + > + acp_reg_writel(AMD_SDW_ENABLE, amd_manager->mmio + ACP_SW_EN); > + do { > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_EN_STATUS); > + if (val) > + break; > + usleep_range(10, 50); > + } while (retry_count++ < AMD_SDW_STAT_MAX_RETRY_COUNT); > + > + if (retry_count > AMD_SDW_STAT_MAX_RETRY_COUNT) > + return -ETIMEDOUT; > + > + /* Soundwire manager bus reset */ > + acp_reg_writel(AMD_SDW_BUS_RESET_REQ, amd_manager->mmio + ACP_SW_BUS_RESET_CTRL); > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_BUS_RESET_CTRL); > + while (!(val & AMD_SDW_BUS_RESET_DONE)) { > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_BUS_RESET_CTRL); > + if (timeout > AMD_DELAY_LOOP_ITERATION) > + break; > + usleep_range(1, 5); > + timeout++; > + } > + if (timeout == AMD_DELAY_LOOP_ITERATION) > + return -ETIMEDOUT; > + timeout = 0; > + acp_reg_writel(AMD_SDW_BUS_RESET_CLEAR_REQ, amd_manager->mmio + ACP_SW_BUS_RESET_CTRL); > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_BUS_RESET_CTRL); > + while (val) { > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_BUS_RESET_CTRL); > + if (timeout > AMD_DELAY_LOOP_ITERATION) > + break; > + usleep_range(1, 5); > + timeout++; > + } > + if (timeout == AMD_DELAY_LOOP_ITERATION) { > + dev_err(amd_manager->dev, "Failed to reset Soundwire manager instance%d\n", > + amd_manager->instance); > + return -ETIMEDOUT; > + } > + retry_count = 0; > + acp_reg_writel(AMD_SDW_DISABLE, amd_manager->mmio + ACP_SW_EN); > + do { > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_EN_STATUS); > + if (!val) > + break; > + usleep_range(10, 50); > + } while (retry_count++ < AMD_SDW_STAT_MAX_RETRY_COUNT); > + > + if (retry_count > AMD_SDW_STAT_MAX_RETRY_COUNT) > + return -ETIMEDOUT; > + return 0; > +} > + > +static int amd_enable_sdw_manager(struct amd_sdw_manager *amd_manager) > +{ > + u32 val = 0; useless init > + u32 retry_count = 0; > + > + acp_reg_writel(AMD_SDW_ENABLE, amd_manager->mmio + ACP_SW_EN); > + do { > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_EN_STATUS); > + if (val) > + break; > + usleep_range(10, 50); > + } while (retry_count++ < AMD_SDW_STAT_MAX_RETRY_COUNT); > + > + if (retry_count > AMD_SDW_STAT_MAX_RETRY_COUNT) > + return -ETIMEDOUT; > + return 0; > +} > + > +static int amd_disable_sdw_manager(struct amd_sdw_manager *amd_manager) > +{ > + u32 val = 0; useless init > + u32 retry_count = 0; > + > + acp_reg_writel(AMD_SDW_DISABLE, amd_manager->mmio + ACP_SW_EN); > + /* > + * After invoking manager disable sequence, check whether > + * manager has executed clock stop sequence. In this case, > + * manager should ignore checking enable status register. > + */ > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_CLK_RESUME_CTRL); > + if (val) > + return 0; > + > + do { > + val = acp_reg_readl(amd_manager->mmio + ACP_SW_EN_STATUS); > + if (!val) > + break; > + usleep_range(10, 50); > + } while (retry_count++ < AMD_SDW_STAT_MAX_RETRY_COUNT); > + > + if (retry_count > AMD_SDW_STAT_MAX_RETRY_COUNT) > + return -ETIMEDOUT; > + return 0; > +} > + > +static void amd_enable_sdw_interrupts(struct amd_sdw_manager *amd_manager) > +{ > + struct sdw_manager_reg_mask *reg_mask = amd_manager->reg_mask; > + u32 val; > + > + mutex_lock(amd_manager->sdw_lock); > + val = acp_reg_readl(amd_manager->acp_mmio + ACP_EXTERNAL_INTR_CNTL(amd_manager->instance)); > + val |= reg_mask->acp_sdw_intr_mask; > + acp_reg_writel(val, amd_manager->acp_mmio + ACP_EXTERNAL_INTR_CNTL(amd_manager->instance)); > + val = acp_reg_readl(amd_manager->acp_mmio + ACP_EXTERNAL_INTR_CNTL(amd_manager->instance)); > + mutex_unlock(amd_manager->sdw_lock); > + dev_dbg(amd_manager->dev, "%s: acp_ext_intr_ctrl[0x%x]:0x%x\n", __func__, > + ACP_EXTERNAL_INTR_CNTL(amd_manager->instance), val); > + val = acp_reg_readl(amd_manager->acp_mmio + ACP_EXTERNAL_INTR_STAT(amd_manager->instance)); > + if (val) > + acp_reg_writel(val, amd_manager->acp_mmio + > + ACP_EXTERNAL_INTR_STAT(amd_manager->instance)); > + > + acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio + > + ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7); > + acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11, amd_manager->mmio + > + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11); > + acp_reg_writel(AMD_SDW_IRQ_ERROR_MASK, amd_manager->mmio + ACP_SW_ERROR_INTR_MASK); > +} > + > +static void amd_disable_sdw_interrupts(struct amd_sdw_manager *amd_manager) > +{ > + struct sdw_manager_reg_mask *reg_mask = amd_manager->reg_mask; > + u32 val; > + > + mutex_lock(amd_manager->sdw_lock); > + val = acp_reg_readl(amd_manager->acp_mmio + ACP_EXTERNAL_INTR_CNTL(amd_manager->instance)); > + val &= ~reg_mask->acp_sdw_intr_mask; > + acp_reg_writel(val, amd_manager->acp_mmio + ACP_EXTERNAL_INTR_CNTL(amd_manager->instance)); > + mutex_unlock(amd_manager->sdw_lock); > + > + acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7); > + acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11); > + acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_ERROR_INTR_MASK); > +} > + > +static void amd_sdw_set_frameshape(struct amd_sdw_manager *amd_manager) > +{ > + u32 frame_size; > + > + frame_size = (amd_manager->rows_index << 3) | amd_manager->cols_index; > + acp_reg_writel(frame_size, amd_manager->mmio + ACP_SW_FRAMESIZE); > +} > + > +static void amd_sdw_ctl_word_prep(u32 *low_word, u32 *high_word, u32 cmd_type, > + struct sdw_msg *msg, int cmd_offset) > +{ > + u32 low_data = 0, high_data = 0; init for high_data is useless > + u16 addr; > + u8 addr_high, addr_low; > + u8 data = 0; > + > + addr = msg->addr + cmd_offset; > + addr_high = (addr & 0xFF00) >> 8; > + addr_low = addr & 0xFF; > + > + if (cmd_type == AMD_SDW_CMD_WRITE) > + data = msg->buf[cmd_offset]; > + > + high_data = FIELD_PREP(AMD_SDW_MCP_CMD_DEV_ADDR, msg->dev_num); > + high_data |= FIELD_PREP(AMD_SDW_MCP_CMD_COMMAND, cmd_type); > + high_data |= FIELD_PREP(AMD_SDW_MCP_CMD_REG_ADDR_HIGH, addr_high); > + low_data |= FIELD_PREP(AMD_SDW_MCP_CMD_REG_ADDR_LOW, addr_low); > + low_data |= FIELD_PREP(AMD_SDW_MCP_CMD_REG_DATA, data); > + > + *high_word = high_data; > + *low_word = low_data; > +} > + > +static u64 amd_sdw_send_cmd_get_resp(struct amd_sdw_manager *amd_manager, u32 lword, u32 uword) > +{ > + u64 resp = 0; useless init > + u32 resp_lower, resp_high; > + u32 sts = 0; useless init > + u32 timeout = 0; > + > + sts = acp_reg_readl(amd_manager->mmio + ACP_SW_IMM_CMD_STS); > + while (sts & AMD_SDW_IMM_CMD_BUSY) { > + sts = acp_reg_readl(amd_manager->mmio + ACP_SW_IMM_CMD_STS); > + if (timeout > AMD_SDW_RETRY_COUNT) { > + dev_err(amd_manager->dev, "SDW%x previous cmd status clear failed\n", > + amd_manager->instance); > + return -ETIMEDOUT; > + } > + timeout++; > + } > + > + timeout = 0; > + if (sts & AMD_SDW_IMM_RES_VALID) { > + dev_err(amd_manager->dev, "SDW%x manager is in bad state\n", amd_manager->instance); > + acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_IMM_CMD_STS); > + } > + acp_reg_writel(uword, amd_manager->mmio + ACP_SW_IMM_CMD_UPPER_WORD); > + acp_reg_writel(lword, amd_manager->mmio + ACP_SW_IMM_CMD_LOWER_QWORD); > + > + sts = acp_reg_readl(amd_manager->mmio + ACP_SW_IMM_CMD_STS); > + while (!(sts & AMD_SDW_IMM_RES_VALID)) { > + sts = acp_reg_readl(amd_manager->mmio + ACP_SW_IMM_CMD_STS); > + if (timeout > AMD_SDW_RETRY_COUNT) { > + dev_err(amd_manager->dev, "SDW%x cmd response timeout occurred\n", > + amd_manager->instance); > + return -ETIMEDOUT; > + } > + timeout++; > + } > + resp_high = acp_reg_readl(amd_manager->mmio + ACP_SW_IMM_RESP_UPPER_WORD); > + resp_lower = acp_reg_readl(amd_manager->mmio + ACP_SW_IMM_RESP_LOWER_QWORD); > + timeout = 0; > + acp_reg_writel(AMD_SDW_IMM_RES_VALID, amd_manager->mmio + ACP_SW_IMM_CMD_STS); > + while ((sts & AMD_SDW_IMM_RES_VALID)) { > + sts = acp_reg_readl(amd_manager->mmio + ACP_SW_IMM_CMD_STS); > + if (timeout > AMD_SDW_RETRY_COUNT) { > + dev_err(amd_manager->dev, "SDW%x cmd status retry failed\n", > + amd_manager->instance); > + return -ETIMEDOUT; > + } > + timeout++; > + } > + resp = resp_high; > + resp = (resp << 32) | resp_lower; > + return resp; > +} > +static unsigned int _amd_sdw_xfer_msg(struct amd_sdw_manager *amd_manager, struct sdw_msg *msg, > + int cmd, int cmd_offset) > +{ > + u64 response = 0; useless init > + u32 uword = 0, lword = 0; > + > + amd_sdw_ctl_word_prep(&lword, &uword, cmd, msg, cmd_offset); > + response = amd_sdw_send_cmd_get_resp(amd_manager, lword, uword); > + return amd_sdw_fill_msg_resp(amd_manager, msg, response, cmd_offset); > +} > + > +static enum sdw_command_response amd_sdw_xfer_msg(struct sdw_bus *bus, struct sdw_msg *msg) > +{ > + struct amd_sdw_manager *amd_manager = to_amd_sdw(bus); > + int ret, i; > + int cmd = 0; > + > + ret = amd_prep_msg(amd_manager, msg, &cmd); > + if (ret) > + return SDW_CMD_FAIL_OTHER; > + for (i = 0; i < msg->len; i++) { > + ret = _amd_sdw_xfer_msg(amd_manager, msg, cmd, i); > + if (ret) > + return ret; > + } > + return SDW_CMD_OK; > +} > + > +static u32 amd_sdw_read_ping_status(struct sdw_bus *bus) > +{ > + struct amd_sdw_manager *amd_manager = to_amd_sdw(bus); > + u64 response; > + u32 slave_stat = 0; useless init > + > + response = amd_sdw_send_cmd_get_resp(amd_manager, 0, 0); > + /* slave status from ping response*/ > + slave_stat = FIELD_GET(AMD_SDW_MCP_SLAVE_STAT_0_3, response); > + slave_stat |= FIELD_GET(AMD_SDW_MCP_SLAVE_STAT_4_11, response) << 8; > + dev_dbg(amd_manager->dev, "%s: slave_stat:0x%x\n", __func__, slave_stat); > + return slave_stat; > +} > +static void amd_sdw_probe_work(struct work_struct *work) > +{ > + struct amd_sdw_manager *amd_manager = container_of(work, struct amd_sdw_manager, > + probe_work); > + struct sdw_master_prop *prop; > + int ret; > + > + prop = &amd_manager->bus.prop; > + if (!prop->hw_disabled) { > + amd_enable_sdw_pads(amd_manager); > + ret = amd_init_sdw_manager(amd_manager); > + if (ret) > + return; > + amd_enable_sdw_interrupts(amd_manager); > + ret = amd_enable_sdw_manager(amd_manager); > + if (ret) > + return; > + amd_sdw_set_frameshape(amd_manager); > + } > +} There should be an explanation as to why you need a workqueue to complete the probe. > + > +static int amd_sdw_manager_probe(struct platform_device *pdev) > +{ > + const struct acp_sdw_pdata *pdata = pdev->dev.platform_data; > + struct resource *res; > + struct device *dev = &pdev->dev; > + struct sdw_master_prop *prop; > + struct sdw_bus_params *params; > + struct amd_sdw_manager *amd_manager; > + int ret; > + > + if (!pdev->dev.platform_data) { > + dev_err(dev, "platform_data not retrieved\n"); > + return -ENODEV; > + } > + amd_manager = devm_kzalloc(dev, sizeof(struct amd_sdw_manager), GFP_KERNEL); > + if (!amd_manager) > + return -ENOMEM; > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) > + return -ENOMEM; > + amd_manager->acp_mmio = devm_ioremap(dev, res->start, resource_size(res)); > + if (IS_ERR(amd_manager->mmio)) { > + dev_err(dev, "mmio not found\n"); > + return PTR_ERR(amd_manager->mmio); > + } > + amd_manager->instance = pdata->instance; > + amd_manager->mmio = amd_manager->acp_mmio + > + (amd_manager->instance * SDW_MANAGER_REG_OFFSET); > + amd_manager->sdw_lock = pdata->sdw_lock; > + amd_manager->cols_index = sdw_find_col_index(AMD_SDW_DEFAULT_COLUMNS); > + amd_manager->rows_index = sdw_find_row_index(AMD_SDW_DEFAULT_ROWS); > + amd_manager->dev = dev; > + amd_manager->bus.ops = &amd_sdw_ops; > + amd_manager->bus.port_ops = &amd_sdw_port_ops; > + amd_manager->bus.compute_params = &amd_sdw_compute_params; > + amd_manager->bus.clk_stop_timeout = 200; > + amd_manager->bus.link_id = amd_manager->instance; > + switch (amd_manager->instance) { > + case ACP_SDW0: > + amd_manager->num_dout_ports = AMD_SDW0_MAX_TX_PORTS; > + amd_manager->num_din_ports = AMD_SDW0_MAX_RX_PORTS; > + break; > + case ACP_SDW1: > + amd_manager->num_dout_ports = AMD_SDW1_MAX_TX_PORTS; > + amd_manager->num_din_ports = AMD_SDW1_MAX_RX_PORTS; > + break; > + default: > + return -EINVAL; > + } > + amd_manager->reg_mask = &sdw_manager_reg_mask_array[amd_manager->instance]; > + params = &amd_manager->bus.params; > + params->max_dr_freq = AMD_SDW_DEFAULT_CLK_FREQ * 2; > + params->curr_dr_freq = AMD_SDW_DEFAULT_CLK_FREQ * 2; > + params->col = AMD_SDW_DEFAULT_COLUMNS; > + params->row = AMD_SDW_DEFAULT_ROWS; > + prop = &amd_manager->bus.prop; > + prop->clk_freq = &amd_sdw_freq_tbl[0]; > + prop->mclk_freq = AMD_SDW_BUS_BASE_FREQ; > + > + ret = sdw_bus_master_add(&amd_manager->bus, dev, dev->fwnode); > + if (ret) { > + dev_err(dev, "Failed to register Soundwire manager(%d)\n", ret); > + return ret; > + } > + dev_set_drvdata(dev, amd_manager); > + INIT_WORK(&amd_manager->probe_work, amd_sdw_probe_work); > + schedule_work(&amd_manager->probe_work); > + return 0; > +} > + > +static int amd_sdw_manager_remove(struct platform_device *pdev) > +{ > + struct amd_sdw_manager *amd_manager = dev_get_drvdata(&pdev->dev); > + int ret; > + > + if (!amd_manager) > + return -ENODEV; is this possible? From the code just above wioth dev_set_drvdata() it seems there's no error code, so the remove can blindly use the pointer. > + cancel_work_sync(&amd_manager->probe_work); > + amd_disable_sdw_interrupts(amd_manager); > + sdw_bus_master_delete(&amd_manager->bus); > + ret = amd_disable_sdw_manager(amd_manager); > + return ret; return amd_disable_sdw_manager(amd_manager); ? > +} > + > +static struct platform_driver amd_sdw_driver = { > + .probe = &amd_sdw_manager_probe, > + .remove = &amd_sdw_manager_remove, > + .driver = { > + .name = "amd_sdw_manager", > + } > +}; > +module_platform_driver(amd_sdw_driver); > +struct acp_sdw_pdata { > + u16 instance; > + /* mutex to protect acp common register access */ > + struct mutex *sdw_lock; may be acp_sdw_lock then? sdw_lock sounds very generic and confusing IMHO. > +};