[RFC,2/2] bluetooth: hci_uart: add LL protocol serdev driver support

diff --git a/drivers/bluetooth/hci_ll.c b/drivers/bluetooth/hci_ll.c
index 02692fe30279..716c610fa54a 100644
--- a/drivers/bluetooth/hci_ll.c
+++ b/drivers/bluetooth/hci_ll.c
@@ -34,20 +34,23 @@ 
 #include <linux/sched.h>
 #include <linux/types.h>
 #include <linux/fcntl.h>
+#include <linux/firmware.h>
 #include <linux/interrupt.h>
 #include <linux/ptrace.h>
 #include <linux/poll.h>
 
 #include <linux/slab.h>
-#include <linux/tty.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/signal.h>
 #include <linux/ioctl.h>
+#include <linux/serdev.h>
 #include <linux/skbuff.h>
+#include <linux/ti_wilink_st.h>
 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
+#include <linux/gpio/consumer.h>
 
 #include "hci_uart.h"
 
@@ -76,6 +79,12 @@  struct hcill_cmd {
 	u8 cmd;
 } __packed;
 
+struct ll_device {
+	struct hci_uart hu;
+	struct serdev_device *serdev;
+	struct gpio_desc *nshutdown;
+};
+
 struct ll_struct {
 	unsigned long rx_state;
 	unsigned long rx_count;
@@ -164,6 +173,11 @@  static int ll_close(struct hci_uart *hu)
 
 	kfree_skb(ll->rx_skb);
 
+	if (hu->serdev) {
+		struct ll_device *lldev = serdev_device_get_drvdata(hu->serdev);
+		gpiod_set_value_cansleep(lldev->nshutdown, 1);
+	}
+
 	hu->priv = NULL;
 
 	kfree(ll);
@@ -171,6 +185,184 @@  static int ll_close(struct hci_uart *hu)
 	return 0;
 }
 
+static int read_local_version(struct hci_dev *hdev)
+{
+	int err = 0;
+	unsigned short version = 0;
+	struct sk_buff *skb;
+	struct hci_rp_read_local_version *ver;
+
+	skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_VERSION, 0, NULL, HCI_INIT_TIMEOUT);
+	if (IS_ERR(skb)) {
+		bt_dev_err(hdev, "Reading TI version information failed (%ld)",
+			   PTR_ERR(skb));
+		err = PTR_ERR(skb);
+		goto out;
+	}
+	if (skb->len != sizeof(*ver)) {
+		err = -EILSEQ;
+		goto out;
+	}
+
+	ver = (struct hci_rp_read_local_version *)skb->data;
+	if (le16_to_cpu(ver->manufacturer) != 13) {
+		err = -ENODEV;
+		goto out;
+	}
+
+	version = le16_to_cpu(ver->lmp_subver);
+
+out:
+	if (err) bt_dev_err(hdev, "Failed to read TI version info: %d", err);
+	kfree_skb(skb);
+	return err ? err : version;
+}
+
+/**
+ * download_firmware -
+ *	internal function which parses through the .bts firmware
+ *	script file intreprets SEND, DELAY actions only as of now
+ */
+static int download_firmware(struct ll_device *lldev)
+{
+	unsigned short chip, min_ver, maj_ver;
+	int version, err, len;
+	unsigned char *ptr, *action_ptr;
+	unsigned char bts_scr_name[40];	/* 40 char long bts scr name? */
+	const struct firmware *fw;
+	struct sk_buff *skb;
+	struct hci_command *cmd;
+
+	version = read_local_version(lldev->hu.hdev);
+	if (version < 0)
+		return version;
+
+	chip = (version & 0x7C00) >> 10;
+	min_ver = (version & 0x007F);
+	maj_ver = (version & 0x0380) >> 7;
+	if (version & 0x8000)
+		maj_ver |= 0x0008;
+
+	snprintf(bts_scr_name, sizeof(bts_scr_name),
+		 "ti-connectivity/TIInit_%d.%d.%d.bts",
+		 chip, maj_ver, min_ver);
+
+	err = request_firmware(&fw, bts_scr_name, &lldev->serdev->dev);
+	if (err || !fw->data || !fw->size) {
+		pr_err(" request_firmware failed(errno %d) for %s", err,
+			   bts_scr_name);
+		return -EINVAL;
+	}
+	ptr = (void *)fw->data;
+	len = fw->size;
+	/* bts_header to remove out magic number and
+	 * version
+	 */
+	ptr += sizeof(struct bts_header);
+	len -= sizeof(struct bts_header);
+
+	while (len > 0 && ptr) {
+		pr_debug(" action size %d, type %d ",
+			   ((struct bts_action *)ptr)->size,
+			   ((struct bts_action *)ptr)->type);
+
+		action_ptr = &(((struct bts_action *)ptr)->data[0]);
+
+		switch (((struct bts_action *)ptr)->type) {
+		case ACTION_SEND_COMMAND:	/* action send */
+			pr_debug("S");
+			cmd = (struct hci_command *)action_ptr;
+			if (cmd->opcode == 0xff36) {
+				/* ignore remote change
+				 * baud rate HCI VS command */
+				pr_warn("change remote baud"
+				    " rate command in firmware");
+				break;
+			}
+			if (cmd->prefix != 1)
+				printk("command type %d\n", cmd->prefix);
+
+			skb = __hci_cmd_sync(lldev->hu.hdev, cmd->opcode, cmd->plen, &cmd->speed, HCI_INIT_TIMEOUT);
+			if (IS_ERR(skb)) {
+				printk("send command failed\n");
+				goto out_rel_fw;
+			}
+			kfree_skb(skb);
+			break;
+		case ACTION_WAIT_EVENT:  /* wait */
+			/* no need to wait as command was synchronous */
+			pr_debug("W");
+			break;
+		case ACTION_DELAY:	/* sleep */
+			pr_info("sleep command in scr");
+			mdelay(((struct bts_action_delay *)action_ptr)->msec);
+			break;
+		}
+		len -= (sizeof(struct bts_action) +
+			((struct bts_action *)ptr)->size);
+		ptr += sizeof(struct bts_action) +
+			((struct bts_action *)ptr)->size;
+	}
+
+out_rel_fw:
+	/* fw download complete */
+	release_firmware(fw);
+	return err;
+}
+
+static int ll_setup(struct hci_uart *hu)
+{
+	int err, retry = 3;
+	struct ll_device *lldev;
+	u32 speed;
+
+	if (!hu->serdev)
+		return 0;
+
+	lldev = serdev_device_get_drvdata(hu->serdev);
+
+	serdev_device_set_flow_control(hu->serdev, true);
+
+	do {
+		/* Configure BT nShutdown to HIGH state */
+		gpiod_set_value_cansleep(lldev->nshutdown, 1);
+		msleep(5);	/* FIXME: a proper toggle */
+		gpiod_set_value_cansleep(lldev->nshutdown, 0);
+		msleep(100);
+
+		err = download_firmware(lldev);
+		if (err != 0) {
+			/* ldisc installed but fw download failed,
+			 * flush uart & power cycle BT_EN */
+			pr_err("download firmware failed");
+			continue;
+		} else {	/* on success don't retry */
+			break;
+		}
+	} while (retry--);
+
+	if (err)
+		return err;
+
+	/* Operational speed if any */
+	if (hu->oper_speed)
+		speed = hu->oper_speed;
+	else if (hu->proto->oper_speed)
+		speed = hu->proto->oper_speed;
+	else
+		speed = 0;
+
+	if (speed) {
+		struct sk_buff *skb = __hci_cmd_sync(hu->hdev, 0xff36, sizeof(speed), &speed, HCI_INIT_TIMEOUT);
+		if (!IS_ERR(skb)) {
+			kfree_skb(skb);
+			serdev_device_set_baudrate(hu->serdev, speed);
+		}
+	}
+
+	return 0;
+}
+
 /*
  * internal function, which does common work of the device wake up process:
  * 1. places all pending packets (waiting in tx_wait_q list) in txq list.
@@ -508,6 +700,7 @@  static struct sk_buff *ll_dequeue(struct hci_uart *hu)
 static const struct hci_uart_proto llp = {
 	.id		= HCI_UART_LL,
 	.name		= "LL",
+	.setup		= ll_setup,
 	.open		= ll_open,
 	.close		= ll_close,
 	.recv		= ll_recv,
@@ -525,3 +718,56 @@  int __exit ll_deinit(void)
 {
 	return hci_uart_unregister_proto(&llp);
 }
+
+static int hci_ti_probe(struct serdev_device *serdev)
+{
+	struct hci_uart *hu;
+	struct ll_device *lldev;
+	u32 max_speed = 3000000;
+
+	lldev = devm_kzalloc(&serdev->dev, sizeof(struct ll_device), GFP_KERNEL);
+	if (!lldev)
+		return -ENOMEM;
+	hu = &lldev->hu;
+
+	serdev_device_set_drvdata(serdev, lldev);
+	lldev->serdev = hu->serdev = serdev;
+
+	lldev->nshutdown = devm_gpiod_get(&serdev->dev, "shutdown", GPIOD_OUT_HIGH);
+	if (IS_ERR(lldev->nshutdown))
+		return PTR_ERR(lldev->nshutdown);
+
+	of_property_read_u32(serdev->dev.of_node, "max-speed", &max_speed);
+	hci_uart_set_speeds(hu, 115200, max_speed);
+
+	return hci_uart_register_device(hu, &llp);
+}
+
+static void hci_ti_remove(struct serdev_device *serdev)
+{
+	struct ll_device *lldev = serdev_device_get_drvdata(serdev);
+	struct hci_uart *hu = &lldev->hu;
+	struct hci_dev *hdev = hu->hdev;
+
+	cancel_work_sync(&hu->write_work);
+
+	hci_unregister_dev(hdev);
+	hci_free_dev(hdev);
+	hu->proto->close(hu);
+}
+
+static const struct of_device_id hci_ti_of_match[] = {
+	{ .compatible = "ti,wl1835-st" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, hci_ti_of_match);
+
+static struct serdev_device_driver hci_ti_drv = {
+	.driver		= {
+		.name	= "hci-ti",
+		.of_match_table = of_match_ptr(hci_ti_of_match),
+	},
+	.probe	= hci_ti_probe,
+	.remove	= hci_ti_remove,
+};
+module_serdev_device_driver(hci_ti_drv);