diff options
Diffstat (limited to 'drivers/soundwire/cadence_master.c')
| -rw-r--r-- | drivers/soundwire/cadence_master.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index d7f01d39767b..dc29556eaf94 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -231,6 +231,24 @@ static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value) return -EAGAIN; } +static int cdns_set_wait(struct sdw_cdns *cdns, int offset, u32 mask, u32 value) +{ + int timeout = 10; + u32 reg_read; + + /* Wait for bit to be set */ + do { + reg_read = readl(cdns->registers + offset); + if ((reg_read & mask) == value) + return 0; + + timeout--; + usleep_range(50, 100); + } while (timeout != 0); + + return -ETIMEDOUT; +} + /* * all changes to the MCP_CONFIG, MCP_CONTROL, MCP_CMDCTRL and MCP_PHYCTRL * need to be confirmed with a write to MCP_CONFIG_UPDATE @@ -1224,6 +1242,145 @@ bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns) EXPORT_SYMBOL(sdw_cdns_is_clock_stop); /** + * sdw_cdns_clock_stop: Cadence clock stop configuration routine + * + * @cdns: Cadence instance + * @block_wake: prevent wakes if required by the platform + */ +int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake) +{ + bool slave_present = false; + struct sdw_slave *slave; + int ret; + + /* Check suspend status */ + if (sdw_cdns_is_clock_stop(cdns)) { + dev_dbg(cdns->dev, "Clock is already stopped\n"); + return 0; + } + + /* + * For specific platforms, it is required to be able to put + * master into a state in which it ignores wake-up trials + * in clock stop state + */ + if (block_wake) + cdns_updatel(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_BLOCK_WAKEUP, + CDNS_MCP_CONTROL_BLOCK_WAKEUP); + + list_for_each_entry(slave, &cdns->bus.slaves, node) { + if (slave->status == SDW_SLAVE_ATTACHED || + slave->status == SDW_SLAVE_ALERT) { + slave_present = true; + break; + } + } + + /* + * This CMD_ACCEPT should be used when there are no devices + * attached on the link when entering clock stop mode. If this is + * not set and there is a broadcast write then the command ignored + * will be treated as a failure + */ + if (!slave_present) + cdns_updatel(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_CMD_ACCEPT, + CDNS_MCP_CONTROL_CMD_ACCEPT); + else + cdns_updatel(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_CMD_ACCEPT, 0); + + /* commit changes */ + ret = cdns_config_update(cdns); + if (ret < 0) { + dev_err(cdns->dev, "%s: config_update failed\n", __func__); + return ret; + } + + /* Prepare slaves for clock stop */ + ret = sdw_bus_prep_clk_stop(&cdns->bus); + if (ret < 0) { + dev_err(cdns->dev, "prepare clock stop failed %d", ret); + return ret; + } + + /* + * Enter clock stop mode and only report errors if there are + * Slave devices present (ALERT or ATTACHED) + */ + ret = sdw_bus_clk_stop(&cdns->bus); + if (ret < 0 && slave_present && ret != -ENODATA) { + dev_err(cdns->dev, "bus clock stop failed %d", ret); + return ret; + } + + ret = cdns_set_wait(cdns, CDNS_MCP_STAT, + CDNS_MCP_STAT_CLK_STOP, + CDNS_MCP_STAT_CLK_STOP); + if (ret < 0) + dev_err(cdns->dev, "Clock stop failed %d\n", ret); + + return ret; +} +EXPORT_SYMBOL(sdw_cdns_clock_stop); + +/** + * sdw_cdns_clock_restart: Cadence PM clock restart configuration routine + * + * @cdns: Cadence instance + * @bus_reset: context may be lost while in low power modes and the bus + * may require a Severe Reset and re-enumeration after a wake. + */ +int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset) +{ + int ret; + + ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_CLK_STOP_CLR); + if (ret < 0) { + dev_err(cdns->dev, "Couldn't exit from clock stop\n"); + return ret; + } + + ret = cdns_set_wait(cdns, CDNS_MCP_STAT, CDNS_MCP_STAT_CLK_STOP, 0); + if (ret < 0) { + dev_err(cdns->dev, "clock stop exit failed %d\n", ret); + return ret; + } + + cdns_updatel(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_BLOCK_WAKEUP, 0); + + /* + * clear CMD_ACCEPT so that the command ignored + * will be treated as a failure during a broadcast write + */ + cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT, 0); + + if (!bus_reset) { + + /* enable bus operations with clock and data */ + cdns_updatel(cdns, CDNS_MCP_CONFIG, + CDNS_MCP_CONFIG_OP, + CDNS_MCP_CONFIG_OP_NORMAL); + + ret = cdns_config_update(cdns); + if (ret < 0) { + dev_err(cdns->dev, "%s: config_update failed\n", __func__); + return ret; + } + + ret = sdw_bus_exit_clk_stop(&cdns->bus); + if (ret < 0) + dev_err(cdns->dev, "bus failed to exit clock stop %d\n", ret); + } + + return ret; +} +EXPORT_SYMBOL(sdw_cdns_clock_restart); + +/** * sdw_cdns_probe() - Cadence probe routine * @cdns: Cadence instance */ |