Qualcomm SoundWire controller supports Auto Enumeration of the
devices within the IP. This patch enables support for this feature.

Signed-off-by: Srinivas Kandagatla <srinivas.kandaga...@linaro.org>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.boss...@linux.intel.com>
---
 drivers/soundwire/qcom.c | 86 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 81 insertions(+), 5 deletions(-)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index 6a563fb52444..c6c923329b15 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -57,6 +57,8 @@
 #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_ENUMERATOR_SLAVE_DEV_ID_1(m)              (0x530 + 0x8 * (m))
+#define SWRM_ENUMERATOR_SLAVE_DEV_ID_2(m)              (0x534 + 0x8 * (m))
 #define SWRM_MCP_FRAME_CTRL_BANK_ADDR(m)               (0x101C + 0x40 * (m))
 #define SWRM_MCP_FRAME_CTRL_BANK_COL_CTRL_BMSK                 GENMASK(2, 0)
 #define SWRM_MCP_FRAME_CTRL_BANK_ROW_CTRL_BMSK                 GENMASK(7, 3)
@@ -143,6 +145,7 @@ struct qcom_swrm_ctrl {
        enum sdw_slave_status status[SDW_MAX_DEVICES];
        int (*reg_read)(struct qcom_swrm_ctrl *ctrl, int reg, u32 *val);
        int (*reg_write)(struct qcom_swrm_ctrl *ctrl, int reg, int val);
+       u32 slave_status;
 };
 
 struct qcom_swrm_data {
@@ -342,6 +345,7 @@ static void qcom_swrm_get_device_status(struct 
qcom_swrm_ctrl *ctrl)
        int i;
 
        ctrl->reg_read(ctrl, SWRM_MCP_SLV_STATUS, &val);
+       ctrl->slave_status = val;
 
        for (i = 0; i < SDW_MAX_DEVICES; i++) {
                u32 s;
@@ -352,10 +356,74 @@ static void qcom_swrm_get_device_status(struct 
qcom_swrm_ctrl *ctrl)
        }
 }
 
+static void qcom_swrm_set_slave_dev_num(struct sdw_bus *bus,
+                                       struct sdw_slave *slave, int devnum)
+{
+       struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
+       u32 status;
+
+       ctrl->reg_read(ctrl, SWRM_MCP_SLV_STATUS, &status);
+       status = (status >> (devnum * SWRM_MCP_SLV_STATUS_SZ));
+       status &= SWRM_MCP_SLV_STATUS_MASK;
+
+       if (status == SDW_SLAVE_ATTACHED) {
+               if (slave)
+                       slave->dev_num = devnum;
+               mutex_lock(&bus->bus_lock);
+               set_bit(devnum, bus->assigned);
+               mutex_unlock(&bus->bus_lock);
+       }
+}
+
+static int qcom_swrm_enumerate(struct sdw_bus *bus)
+{
+       struct qcom_swrm_ctrl *ctrl = to_qcom_sdw(bus);
+       struct sdw_slave *slave, *_s;
+       struct sdw_slave_id id;
+       u32 val1, val2;
+       bool found;
+       u64 addr;
+       int i;
+       char *buf1 = (char *)&val1, *buf2 = (char *)&val2;
+
+       for (i = 1; i <= SDW_MAX_DEVICES; i++) {
+               /*SCP_Devid5 - Devid 4*/
+               ctrl->reg_read(ctrl, SWRM_ENUMERATOR_SLAVE_DEV_ID_1(i), &val1);
+
+               /*SCP_Devid3 - DevId 2 Devid 1 Devid 0*/
+               ctrl->reg_read(ctrl, SWRM_ENUMERATOR_SLAVE_DEV_ID_2(i), &val2);
+
+               if (!val1 && !val2)
+                       break;
+
+               addr = buf2[1] | (buf2[0] << 8) | (buf1[3] << 16) |
+                       ((u64)buf1[2] << 24) | ((u64)buf1[1] << 32) |
+                       ((u64)buf1[0] << 40);
+
+               sdw_extract_slave_id(bus, addr, &id);
+               found = false;
+               /* Now compare with entries */
+               list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
+                       if (sdw_compare_devid(slave, id) == 0) {
+                               qcom_swrm_set_slave_dev_num(bus, slave, i);
+                               found = true;
+                               break;
+                       }
+               }
+
+               if (!found) {
+                       qcom_swrm_set_slave_dev_num(bus, NULL, i);
+                       sdw_slave_add(bus, &id, NULL);
+               }
+       }
+
+       return 0;
+}
+
 static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
 {
        struct qcom_swrm_ctrl *swrm = dev_id;
-       u32 value, intr_sts, intr_sts_masked;
+       u32 value, intr_sts, intr_sts_masked, slave_status;
        u32 i;
        u8 devnum = 0;
        int ret = IRQ_HANDLED;
@@ -384,8 +452,15 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void 
*dev_id)
                        case SWRM_INTERRUPT_STATUS_CHANGE_ENUM_SLAVE_STATUS:
                                dev_err_ratelimited(swrm->dev, "%s: SWR new 
slave attached\n",
                                        __func__);
-                               qcom_swrm_get_device_status(swrm);
-                               sdw_handle_slave_status(&swrm->bus, 
swrm->status);
+                               swrm->reg_read(swrm, SWRM_MCP_SLV_STATUS, 
&slave_status);
+                               if (swrm->slave_status == slave_status) {
+                                       dev_err(swrm->dev, "Slave status not 
changed %x\n",
+                                               slave_status);
+                               } else {
+                                       qcom_swrm_get_device_status(swrm);
+                                       qcom_swrm_enumerate(&swrm->bus);
+                                       sdw_handle_slave_status(&swrm->bus, 
swrm->status);
+                               }
                                break;
                        case SWRM_INTERRUPT_STATUS_MASTER_CLASH_DET:
                                dev_err_ratelimited(swrm->dev,
@@ -472,8 +547,8 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
 
        ctrl->reg_write(ctrl, SWRM_MCP_FRAME_CTRL_BANK_ADDR(0), val);
 
-       /* Disable Auto enumeration */
-       ctrl->reg_write(ctrl, SWRM_ENUMERATOR_CFG_ADDR, 0);
+       /* Enable Auto enumeration */
+       ctrl->reg_write(ctrl, SWRM_ENUMERATOR_CFG_ADDR, 1);
 
        ctrl->intr_mask = SWRM_INTERRUPT_STATUS_RMSK;
        /* Mask soundwire interrupts */
@@ -507,6 +582,7 @@ static int qcom_swrm_init(struct qcom_swrm_ctrl *ctrl)
                ctrl->reg_write(ctrl, SWRM_INTERRUPT_CPU_EN,
                                SWRM_INTERRUPT_STATUS_RMSK);
        }
+       ctrl->slave_status = 0;
        return 0;
 }
 
-- 
2.21.0

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