@@ -225,12 +225,30 @@ static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value)
return 0;
timeout--;
- udelay(50);
+ usleep_range(50, 100);
} while (timeout != 0);
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
@@ -1231,6 +1249,147 @@ 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;
+ u32 status;
+ int ret;
+
+ /* Check suspend status */
+ status = cdns_readl(cdns, CDNS_MCP_STAT);
+ if (status & CDNS_MCP_STAT_CLK_STOP) {
+ dev_dbg(cdns->dev, "Clock is already stopped\n");
+ return 1;
+ }
+
+ /*
+ * 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
@@ -145,6 +145,8 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns);
int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns, bool state);
bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns);
+int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake);
+int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset);
#ifdef CONFIG_DEBUG_FS
void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root);