1 files changed, 415 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-mtk-sch.c b/drivers/usb/host/xhci-mtk-sch.c
new file mode 100644
index 000000000000..c30de7c39f44
--- /dev/null
+++ b/drivers/usb/host/xhci-mtk-sch.c
@@ -0,0 +1,415 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ * Author:
+ *  Zhigang.Wei <zhigang.wei@mediatek.com>
+ *  Chunfeng.Yun <chunfeng.yun@mediatek.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "xhci.h"
+#include "xhci-mtk.h"
+
+#define SS_BW_BOUNDARY	51000
+/* table 5-5. High-speed Isoc Transaction Limits in usb_20 spec */
+#define HS_BW_BOUNDARY	6144
+/* usb2 spec section11.18.1: at most 188 FS bytes per microframe */
+#define FS_PAYLOAD_MAX 188
+
+/* mtk scheduler bitmasks */
+#define EP_BPKTS(p)	((p) & 0x3f)
+#define EP_BCSCOUNT(p)	(((p) & 0x7) << 8)
+#define EP_BBM(p)	((p) << 11)
+#define EP_BOFFSET(p)	((p) & 0x3fff)
+#define EP_BREPEAT(p)	(((p) & 0x7fff) << 16)
+
+static int is_fs_or_ls(enum usb_device_speed speed)
+{
+	return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
+}
+
+/*
+* get the index of bandwidth domains array which @ep belongs to.
+*
+* the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
+* each HS root port is treated as a single bandwidth domain,
+* but each SS root port is treated as two bandwidth domains, one for IN eps,
+* one for OUT eps.
+* @real_port value is defined as follow according to xHCI spec:
+* 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
+* so the bandwidth domain array is organized as follow for simplification:
+* SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
+*/
+static int get_bw_index(struct xhci_hcd *xhci, struct usb_device *udev,
+	struct usb_host_endpoint *ep)
+{
+	struct xhci_virt_device *virt_dev;
+	int bw_index;
+
+	virt_dev = xhci->devs[udev->slot_id];
+
+	if (udev->speed == USB_SPEED_SUPER) {
+		if (usb_endpoint_dir_out(&ep->desc))
+			bw_index = (virt_dev->real_port - 1) * 2;
+		else
+			bw_index = (virt_dev->real_port - 1) * 2 + 1;
+	} else {
+		/* add one more for each SS port */
+		bw_index = virt_dev->real_port + xhci->num_usb3_ports - 1;
+	}
+
+	return bw_index;
+}
+
+static void setup_sch_info(struct usb_device *udev,
+		struct xhci_ep_ctx *ep_ctx, struct mu3h_sch_ep_info *sch_ep)
+{
+	u32 ep_type;
+	u32 ep_interval;
+	u32 max_packet_size;
+	u32 max_burst;
+	u32 mult;
+	u32 esit_pkts;
+
+	ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
+	ep_interval = CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
+	max_packet_size = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
+	max_burst = CTX_TO_MAX_BURST(le32_to_cpu(ep_ctx->ep_info2));
+	mult = CTX_TO_EP_MULT(le32_to_cpu(ep_ctx->ep_info));
+
+	sch_ep->esit = 1 << ep_interval;
+	sch_ep->offset = 0;
+	sch_ep->burst_mode = 0;
+
+	if (udev->speed == USB_SPEED_HIGH) {
+		sch_ep->cs_count = 0;
+
+		/*
+		 * usb_20 spec section5.9
+		 * a single microframe is enough for HS synchromous endpoints
+		 * in a interval
+		 */
+		sch_ep->num_budget_microframes = 1;
+		sch_ep->repeat = 0;
+
+		/*
+		 * xHCI spec section6.2.3.4
+		 * @max_burst is the number of additional transactions
+		 * opportunities per microframe
+		 */
+		sch_ep->pkts = max_burst + 1;
+		sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
+	} else if (udev->speed == USB_SPEED_SUPER) {
+		/* usb3_r1 spec section4.4.7 & 4.4.8 */
+		sch_ep->cs_count = 0;
+		esit_pkts = (mult + 1) * (max_burst + 1);
+		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
+			sch_ep->pkts = esit_pkts;
+			sch_ep->num_budget_microframes = 1;
+			sch_ep->repeat = 0;
+		}
+
+		if (ep_type == ISOC_IN_EP || ep_type == ISOC_OUT_EP) {
+			if (esit_pkts <= sch_ep->esit)
+				sch_ep->pkts = 1;
+			else
+				sch_ep->pkts = roundup_pow_of_two(esit_pkts)
+					/ sch_ep->esit;
+
+			sch_ep->num_budget_microframes =
+				DIV_ROUND_UP(esit_pkts, sch_ep->pkts);
+
+			if (sch_ep->num_budget_microframes > 1)
+				sch_ep->repeat = 1;
+			else
+				sch_ep->repeat = 0;
+		}
+		sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
+	} else if (is_fs_or_ls(udev->speed)) {
+
+		/*
+		 * usb_20 spec section11.18.4
+		 * assume worst cases
+		 */
+		sch_ep->repeat = 0;
+		sch_ep->pkts = 1; /* at most one packet for each microframe */
+		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
+			sch_ep->cs_count = 3; /* at most need 3 CS*/
+			/* one for SS and one for budgeted transaction */
+			sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
+			sch_ep->bw_cost_per_microframe = max_packet_size;
+		}
+		if (ep_type == ISOC_OUT_EP) {
+
+			/*
+			 * the best case FS budget assumes that 188 FS bytes
+			 * occur in each microframe
+			 */
+			sch_ep->num_budget_microframes = DIV_ROUND_UP(
+				max_packet_size, FS_PAYLOAD_MAX);
+			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
+			sch_ep->cs_count = sch_ep->num_budget_microframes;
+		}
+		if (ep_type == ISOC_IN_EP) {
+			/* at most need additional two CS. */
+			sch_ep->cs_count = DIV_ROUND_UP(
+				max_packet_size, FS_PAYLOAD_MAX) + 2;
+			sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
+			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
+		}
+	}
+}
+
+/* Get maximum bandwidth when we schedule at offset slot. */
+static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
+	struct mu3h_sch_ep_info *sch_ep, u32 offset)
+{
+	u32 num_esit;
+	u32 max_bw = 0;
+	int i;
+	int j;
+
+	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
+	for (i = 0; i < num_esit; i++) {
+		u32 base = offset + i * sch_ep->esit;
+
+		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
+			if (sch_bw->bus_bw[base + j] > max_bw)
+				max_bw = sch_bw->bus_bw[base + j];
+		}
+	}
+	return max_bw;
+}
+
+static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
+	struct mu3h_sch_ep_info *sch_ep, int bw_cost)
+{
+	u32 num_esit;
+	u32 base;
+	int i;
+	int j;
+
+	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
+	for (i = 0; i < num_esit; i++) {
+		base = sch_ep->offset + i * sch_ep->esit;
+		for (j = 0; j < sch_ep->num_budget_microframes; j++)
+			sch_bw->bus_bw[base + j] += bw_cost;
+	}
+}
+
+static int check_sch_bw(struct usb_device *udev,
+	struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
+{
+	u32 offset;
+	u32 esit;
+	u32 num_budget_microframes;
+	u32 min_bw;
+	u32 min_index;
+	u32 worst_bw;
+	u32 bw_boundary;
+
+	if (sch_ep->esit > XHCI_MTK_MAX_ESIT)
+		sch_ep->esit = XHCI_MTK_MAX_ESIT;
+
+	esit = sch_ep->esit;
+	num_budget_microframes = sch_ep->num_budget_microframes;
+
+	/*
+	 * Search through all possible schedule microframes.
+	 * and find a microframe where its worst bandwidth is minimum.
+	 */
+	min_bw = ~0;
+	min_index = 0;
+	for (offset = 0; offset < esit; offset++) {
+		if ((offset + num_budget_microframes) > sch_ep->esit)
+			break;
+
+		/*
+		 * usb_20 spec section11.18:
+		 * must never schedule Start-Split in Y6
+		 */
+		if (is_fs_or_ls(udev->speed) && (offset % 8 == 6))
+			continue;
+
+		worst_bw = get_max_bw(sch_bw, sch_ep, offset);
+		if (min_bw > worst_bw) {
+			min_bw = worst_bw;
+			min_index = offset;
+		}
+		if (min_bw == 0)
+			break;
+	}
+	sch_ep->offset = min_index;
+
+	bw_boundary = (udev->speed == USB_SPEED_SUPER)
+				? SS_BW_BOUNDARY : HS_BW_BOUNDARY;
+
+	/* check bandwidth */
+	if (min_bw + sch_ep->bw_cost_per_microframe > bw_boundary)
+		return -ERANGE;
+
+	/* update bus bandwidth info */
+	update_bus_bw(sch_bw, sch_ep, sch_ep->bw_cost_per_microframe);
+
+	return 0;
+}
+
+static bool need_bw_sch(struct usb_host_endpoint *ep,
+	enum usb_device_speed speed, int has_tt)
+{
+	/* only for periodic endpoints */
+	if (usb_endpoint_xfer_control(&ep->desc)
+		|| usb_endpoint_xfer_bulk(&ep->desc))
+		return false;
+
+	/*
+	 * for LS & FS periodic endpoints which its device don't attach
+	 * to TT are also ignored, root-hub will schedule them directly
+	 */
+	if (is_fs_or_ls(speed) && !has_tt)
+		return false;
+
+	return true;
+}
+
+int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
+{
+	struct mu3h_sch_bw_info *sch_array;
+	int num_usb_bus;
+	int i;
+
+	/* ss IN and OUT are separated */
+	num_usb_bus = mtk->num_u3_ports * 2 + mtk->num_u2_ports;
+
+	sch_array = kcalloc(num_usb_bus, sizeof(*sch_array), GFP_KERNEL);
+	if (sch_array == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < num_usb_bus; i++)
+		INIT_LIST_HEAD(&sch_array[i].bw_ep_list);
+
+	mtk->sch_array = sch_array;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_mtk_sch_init);
+
+void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
+{
+	kfree(mtk->sch_array);
+}
+EXPORT_SYMBOL_GPL(xhci_mtk_sch_exit);
+
+int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
+		struct usb_host_endpoint *ep)
+{
+	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
+	struct xhci_hcd *xhci;
+	struct xhci_ep_ctx *ep_ctx;
+	struct xhci_slot_ctx *slot_ctx;
+	struct xhci_virt_device *virt_dev;
+	struct mu3h_sch_bw_info *sch_bw;
+	struct mu3h_sch_ep_info *sch_ep;
+	struct mu3h_sch_bw_info *sch_array;
+	unsigned int ep_index;
+	int bw_index;
+	int ret = 0;
+
+	xhci = hcd_to_xhci(hcd);
+	virt_dev = xhci->devs[udev->slot_id];
+	ep_index = xhci_get_endpoint_index(&ep->desc);
+	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+	ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
+	sch_array = mtk->sch_array;
+
+	xhci_dbg(xhci, "%s() type:%d, speed:%d, mpkt:%d, dir:%d, ep:%p\n",
+		__func__, usb_endpoint_type(&ep->desc), udev->speed,
+		GET_MAX_PACKET(usb_endpoint_maxp(&ep->desc)),
+		usb_endpoint_dir_in(&ep->desc), ep);
+
+	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
+		return 0;
+
+	bw_index = get_bw_index(xhci, udev, ep);
+	sch_bw = &sch_array[bw_index];
+
+	sch_ep = kzalloc(sizeof(struct mu3h_sch_ep_info), GFP_NOIO);
+	if (!sch_ep)
+		return -ENOMEM;
+
+	setup_sch_info(udev, ep_ctx, sch_ep);
+
+	ret = check_sch_bw(udev, sch_bw, sch_ep);
+	if (ret) {
+		xhci_err(xhci, "Not enough bandwidth!\n");
+		kfree(sch_ep);
+		return -ENOSPC;
+	}
+
+	list_add_tail(&sch_ep->endpoint, &sch_bw->bw_ep_list);
+	sch_ep->ep = ep;
+
+	ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(sch_ep->pkts)
+		| EP_BCSCOUNT(sch_ep->cs_count) | EP_BBM(sch_ep->burst_mode));
+	ep_ctx->reserved[1] |= cpu_to_le32(EP_BOFFSET(sch_ep->offset)
+		| EP_BREPEAT(sch_ep->repeat));
+
+	xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
+			sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
+			sch_ep->offset, sch_ep->repeat);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(xhci_mtk_add_ep_quirk);
+
+void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
+		struct usb_host_endpoint *ep)
+{
+	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
+	struct xhci_hcd *xhci;
+	struct xhci_slot_ctx *slot_ctx;
+	struct xhci_virt_device *virt_dev;
+	struct mu3h_sch_bw_info *sch_array;
+	struct mu3h_sch_bw_info *sch_bw;
+	struct mu3h_sch_ep_info *sch_ep;
+	int bw_index;
+
+	xhci = hcd_to_xhci(hcd);
+	virt_dev = xhci->devs[udev->slot_id];
+	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+	sch_array = mtk->sch_array;
+
+	xhci_dbg(xhci, "%s() type:%d, speed:%d, mpks:%d, dir:%d, ep:%p\n",
+		__func__, usb_endpoint_type(&ep->desc), udev->speed,
+		GET_MAX_PACKET(usb_endpoint_maxp(&ep->desc)),
+		usb_endpoint_dir_in(&ep->desc), ep);
+
+	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
+		return;
+
+	bw_index = get_bw_index(xhci, udev, ep);
+	sch_bw = &sch_array[bw_index];
+
+	list_for_each_entry(sch_ep, &sch_bw->bw_ep_list, endpoint) {
+		if (sch_ep->ep == ep) {
+			update_bus_bw(sch_bw, sch_ep,
+				-sch_ep->bw_cost_per_microframe);
+			list_del(&sch_ep->endpoint);
+			kfree(sch_ep);
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);