[PATCH v6 8/9] soundwire: qcom: add auto enumeration support

From: Srinivas Kandagatla
Date: Tue Mar 30 2021 - 10:48:29 EST


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.kandagatla@xxxxxxxxxx>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
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 1ad07784db4b..b1dbaf8263e5 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 {
@@ -343,6 +346,7 @@ 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;
@@ -353,10 +357,74 @@ 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;
@@ -385,8 +453,15 @@ 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,
@@ -473,8 +548,8 @@ 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 */
@@ -508,6 +583,7 @@ 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