[RFC PATCH v2 2/3] bluetooth: ti-st: Add GNSS subdevice for TI Wilink chips

Andreas Kemnade
2024-01-28T18:06:16Z

Some of these chips have GNSS support. GNSS support
is available through channel 9 whilst FM is through channel 8.
Add a platform subdevice for GNSS so that a driver for that
functionality can be build. To avoid having useless GNSS
devices, do it only when the devicetree node namecontains gnss.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
---
drivers/bluetooth/hci_ll.c | 81 ++++++++++++++++++++++++++++++++++++
include/linux/ti_wilink_st.h | 8 ++++
2 files changed, 89 insertions(+)

diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index 4a0b5c3160c2b..09e5a4dbd2f8c 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -32,6 +32,7 @@
#include <linux/signal.h>
#include <linux/ioctl.h>
#include <linux/of.h>
+#include <linux/platform_device.h>
#include <linux/serdev.h>
#include <linux/skbuff.h>
#include <linux/ti_wilink_st.h>
@@ -68,6 +69,9 @@ struct ll_device {
struct gpio_desc *enable_gpio;
struct clk *ext_clk;
bdaddr_t bdaddr;
+
+ void (*gnss_recv_func)(struct device *dev, struct sk_buff *skb);
+ struct platform_device *gnssdev;
};

struct ll_struct {
@@ -78,6 +82,8 @@ struct ll_struct {
struct sk_buff_head tx_wait_q; /* HCILL wait queue */
};

+static int ll_gnss_register(struct ll_device *lldev);
+static int ll_gnss_recv_frame(struct hci_dev *hdev, struct sk_buff *skb);
/*
* Builds and sends an HCILL command packet.
* These are very simple packets with only 1 cmd byte
@@ -411,6 +417,13 @@ static int ll_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
.lsize = 0, \
.maxlen = 0

+#define LL_RECV_GNSS \
+ .type = 9, \
+ .hlen = 3, \
+ .loff = 1, \
+ .lsize = 2
+
+
static const struct h4_recv_pkt ll_recv_pkts[] = {
{ H4_RECV_ACL, .recv = hci_recv_frame },
{ H4_RECV_SCO, .recv = hci_recv_frame },
@@ -419,6 +432,7 @@ static const struct h4_recv_pkt ll_recv_pkts[] = {
{ LL_RECV_SLEEP_ACK, .recv = ll_recv_frame },
{ LL_RECV_WAKE_IND, .recv = ll_recv_frame },
{ LL_RECV_WAKE_ACK, .recv = ll_recv_frame },
+ { LL_RECV_GNSS, .recv = ll_gnss_recv_frame },
};

/* Recv data */
@@ -677,9 +691,69 @@ static int ll_setup(struct hci_uart *hu)
}
}

+ if (strstr(of_node_full_name(serdev->dev.of_node), "gnss"))
+ ll_gnss_register(lldev);
+
+ return 0;
+}
+
+struct hci_dev *st_get_hci(struct device *dev)
+{
+ struct ll_device *lldev = dev_get_drvdata(dev);
+
+ return lldev->hu.hdev;
+}
+EXPORT_SYMBOL(st_get_hci);
+
+void st_set_gnss_recv_func(struct device *dev,
+ void (*recv_frame)(struct device *, struct sk_buff *))
+{
+ struct ll_device *lldev = dev_get_drvdata(dev);
+
+ lldev->gnss_recv_func = recv_frame;
+}
+EXPORT_SYMBOL(st_set_gnss_recv_func);
+
+static int ll_gnss_recv_frame(struct hci_dev *hdev, struct sk_buff *skb)
+{
+ struct hci_uart *hu = hci_get_drvdata(hdev);
+ struct ll_device *lldev = container_of(hu, struct ll_device, hu);
+
+ if (!lldev->gnssdev)
+ return 0;
+
+ if (lldev->gnss_recv_func) {
+ lldev->gnss_recv_func(&lldev->gnssdev->dev, skb);
+ return 0;
+ }
+ kfree_skb(skb);
+
return 0;
}

+static int ll_gnss_register(struct ll_device *lldev)
+{
+ struct platform_device *pdev;
+ int ret;
+
+ pdev = platform_device_alloc("ti-ai2-gnss", PLATFORM_DEVID_AUTO);
+ if (!pdev)
+ return -ENOMEM;
+
+ pdev->dev.parent = &lldev->serdev->dev;
+ lldev->gnssdev = pdev;
+ ret = platform_device_add(pdev);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ lldev->gnssdev = NULL;
+ platform_device_put(pdev);
+ return ret;
+}
+
static const struct hci_uart_proto llp;

static int hci_ti_probe(struct serdev_device *serdev)
@@ -757,12 +831,19 @@ static int hci_ti_probe(struct serdev_device *serdev)
}

return hci_uart_register_device(hu, &llp);
+
+
+ return 0;
}

+
static void hci_ti_remove(struct serdev_device *serdev)
{
struct ll_device *lldev = serdev_device_get_drvdata(serdev);

+ if (lldev->gnssdev)
+ platform_device_unregister(lldev->gnssdev);
+
hci_uart_unregister_device(&lldev->hu);
}

diff --git a/include/linux/ti_wilink_st.h b/include/linux/ti_wilink_st.h
index 10642d4844f0c..eccc2db004069 100644
--- a/include/linux/ti_wilink_st.h
+++ b/include/linux/ti_wilink_st.h
@@ -381,6 +381,14 @@ unsigned long st_ll_getstate(struct st_data_s *);
unsigned long st_ll_sleep_state(struct st_data_s *, unsigned char);
void st_ll_wakeup(struct st_data_s *);

+/**
+ * various funcs used to interact between FM, GPS and BT
+ */
+struct hci_dev *st_get_hci(struct device *dev);
+void st_set_gnss_recv_func(struct device *dev,
+ void (*recv_frame)(struct device *, struct sk_buff *));
+
+
/*
* header information used by st_core.c for FM and GPS
* packet parsing, the bluetooth headers are already available
--
2.39.2