USB: EHCI: EHCI 1.1 addendum: preparation

EHCI 1.1 addendum introduced several energy efficiency extensions for
EHCI USB host controllers:
1. LPM (link power management)
2. Per-port change
3. Shorter periodic frame list
4. Hardware prefetching

This patch is intended to define the HW bits and debug interface for
EHCI 1.1 addendum. The LPM and Per-port change patches will be sent out
after this patch.

Signed-off-by: Jacob Pan <[e-mail]>
Signed-off-by: Alek Du <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/host/ehci-dbg.c

···
 			HCC_64BIT_ADDR(params) ? " 64 bit addr" : "");
 	} else {
 		ehci_dbg (ehci,
-			"%s hcc_params %04x thresh %d uframes %s%s%s\n",
+			"%s hcc_params %04x thresh %d uframes %s%s%s%s%s%s%s\n",
 			label,
 			params,
 			HCC_ISOC_THRES(params),
 			HCC_PGM_FRAMELISTLEN(params) ? "256/512/1024" : "1024",
 			HCC_CANPARK(params) ? " park" : "",
-			HCC_64BIT_ADDR(params) ? " 64 bit addr" : "");
+			HCC_64BIT_ADDR(params) ? " 64 bit addr" : "",
+			HCC_LPM(params) ? " LPM" : "",
+			HCC_PER_PORT_CHANGE_EVENT(params) ? " ppce" : "",
+			HCC_HW_PREFETCH(params) ? " hw prefetch" : "",
+			HCC_32FRAME_PERIODIC_LIST(params) ?
+				" 32 peridic list" : "");
 	}
 }
 #else
···
 dbg_status_buf (char *buf, unsigned len, const char *label, u32 status)
 {
 	return scnprintf (buf, len,
-		"%s%sstatus %04x%s%s%s%s%s%s%s%s%s%s",
+		"%s%sstatus %04x%s%s%s%s%s%s%s%s%s%s%s",
 		label, label [0] ? " " : "", status,
+		(status & STS_PPCE_MASK) ? " PPCE" : "",
 		(status & STS_ASS) ? " Async" : "",
 		(status & STS_PSS) ? " Periodic" : "",
 		(status & STS_RECL) ? " Recl" : "",
···
 dbg_intr_buf (char *buf, unsigned len, const char *label, u32 enable)
 {
 	return scnprintf (buf, len,
-		"%s%sintrenable %02x%s%s%s%s%s%s",
+		"%s%sintrenable %02x%s%s%s%s%s%s%s",
 		label, label [0] ? " " : "", enable,
+		(enable & STS_PPCE_MASK) ? " PPCE" : "",
 		(enable & STS_IAA) ? " IAA" : "",
 		(enable & STS_FATAL) ? " FATAL" : "",
 		(enable & STS_FLR) ? " FLR" : "",
···
 dbg_command_buf (char *buf, unsigned len, const char *label, u32 command)
 {
 	return scnprintf (buf, len,
-		"%s%scommand %06x %s=%d ithresh=%d%s%s%s%s period=%s%s %s",
+		"%s%scommand %07x %s%s%s%s%s%s=%d ithresh=%d%s%s%s%s "
+		"period=%s%s %s",
 		label, label [0] ? " " : "", command,
-		(command & CMD_PARK) ? "park" : "(park)",
+		(command & CMD_HIRD) ? " HIRD" : "",
+		(command & CMD_PPCEE) ? " PPCEE" : "",
+		(command & CMD_FSP) ? " FSP" : "",
+		(command & CMD_ASPE) ? " ASPE" : "",
+		(command & CMD_PSPE) ? " PSPE" : "",
+		(command & CMD_PARK) ? " park" : "(park)",
 		CMD_PARK_CNT (command),
 		(command >> 16) & 0x3f,
 		(command & CMD_LRESET) ? " LReset" : "",
···
 	}
 
 	return scnprintf (buf, len,
-		"%s%sport %d status %06x%s%s sig=%s%s%s%s%s%s%s%s%s%s",
+		"%s%sport:%d status %06x %d %s%s%s%s%s%s "
+		"sig=%s%s%s%s%s%s%s%s%s%s%s",
 		label, label [0] ? " " : "", port, status,
+		status>>25,/*device address */
+		(status & PORT_SSTS)>>23 == PORTSC_SUSPEND_STS_ACK ?
+						" ACK" : "",
+		(status & PORT_SSTS)>>23 == PORTSC_SUSPEND_STS_NYET ?
+						" NYET" : "",
+		(status & PORT_SSTS)>>23 == PORTSC_SUSPEND_STS_STALL ?
+						" STALL" : "",
+		(status & PORT_SSTS)>>23 == PORTSC_SUSPEND_STS_ERR ?
+						" ERR" : "",
 		(status & PORT_POWER) ? " POWER" : "",
 		(status & PORT_OWNER) ? " OWNER" : "",
 		sig,
+		(status & PORT_LPM) ? " LPM" : "",
 		(status & PORT_RESET) ? " RESET" : "",
 		(status & PORT_SUSPEND) ? " SUSPEND" : "",
 		(status & PORT_RESUME) ? " RESUME" : "",
···
 static int debug_periodic_open(struct inode *, struct file *);
 static int debug_registers_open(struct inode *, struct file *);
 static int debug_async_open(struct inode *, struct file *);
+static int debug_lpm_open(struct inode *, struct file *);
+static ssize_t debug_lpm_read(struct file *file, char __user *user_buf,
+				   size_t count, loff_t *ppos);
+static ssize_t debug_lpm_write(struct file *file, const char __user *buffer,
+			      size_t count, loff_t *ppos);
+static int debug_lpm_close(struct inode *inode, struct file *file);
+
 static ssize_t debug_output(struct file*, char __user*, size_t, loff_t*);
 static int debug_close(struct inode *, struct file *);
 
···
 	.open		= debug_registers_open,
 	.read		= debug_output,
 	.release	= debug_close,
+};
+static const struct file_operations debug_lpm_fops = {
+	.owner		= THIS_MODULE,
+	.open		= debug_lpm_open,
+	.read		= debug_lpm_read,
+	.write		= debug_lpm_write,
+	.release	= debug_lpm_close,
 };
 
 static struct dentry *ehci_debug_root;
···
 	return file->private_data ? 0 : -ENOMEM;
 }
 
+static int debug_lpm_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static int debug_lpm_close(struct inode *inode, struct file *file)
+{
+	return 0;
+}
+
+static ssize_t debug_lpm_read(struct file *file, char __user *user_buf,
+				   size_t count, loff_t *ppos)
+{
+	/* TODO: show lpm stats */
+	return 0;
+}
+
+static ssize_t debug_lpm_write(struct file *file, const char __user *user_buf,
+			      size_t count, loff_t *ppos)
+{
+	struct usb_hcd		*hcd;
+	struct ehci_hcd		*ehci;
+	char buf[50];
+	size_t len;
+	u32 temp;
+	unsigned long port;
+	u32 __iomem	*portsc ;
+	u32 params;
+
+	hcd = bus_to_hcd(file->private_data);
+	ehci = hcd_to_ehci(hcd);
+
+	len = min(count, sizeof(buf) - 1);
+	if (copy_from_user(buf, user_buf, len))
+		return -EFAULT;
+	buf[len] = '\0';
+	if (len > 0 && buf[len - 1] == '\n')
+		buf[len - 1] = '\0';
+
+	if (strncmp(buf, "enable", 5) == 0) {
+		if (strict_strtoul(buf + 7, 10, &port))
+			return -EINVAL;
+		params = ehci_readl(ehci, &ehci->caps->hcs_params);
+		if (port > HCS_N_PORTS(params)) {
+			ehci_dbg(ehci, "ERR: LPM on bad port %lu\n", port);
+			return -ENODEV;
+		}
+		portsc = &ehci->regs->port_status[port-1];
+		temp = ehci_readl(ehci, portsc);
+		if (!(temp & PORT_DEV_ADDR)) {
+			ehci_dbg(ehci, "LPM: no device attached\n");
+			return -ENODEV;
+		}
+		temp |= PORT_LPM;
+		ehci_writel(ehci, temp, portsc);
+		printk(KERN_INFO "force enable LPM for port %lu\n", port);
+	} else if (strncmp(buf, "hird=", 5) == 0) {
+		unsigned long hird;
+		if (strict_strtoul(buf + 5, 16, &hird))
+			return -EINVAL;
+		printk(KERN_INFO "setting hird %s %lu\n", buf + 6, hird);
+		temp = ehci_readl(ehci, &ehci->regs->command);
+		temp &= ~CMD_HIRD;
+		temp |= hird << 24;
+		ehci_writel(ehci, temp, &ehci->regs->command);
+	} else if (strncmp(buf, "disable", 7) == 0) {
+		if (strict_strtoul(buf + 8, 10, &port))
+			return -EINVAL;
+		params = ehci_readl(ehci, &ehci->caps->hcs_params);
+		if (port > HCS_N_PORTS(params)) {
+			ehci_dbg(ehci, "ERR: LPM off bad port %lu\n", port);
+			return -ENODEV;
+		}
+		portsc = &ehci->regs->port_status[port-1];
+		temp = ehci_readl(ehci, portsc);
+		if (!(temp & PORT_DEV_ADDR)) {
+			ehci_dbg(ehci, "ERR: no device attached\n");
+			return -ENODEV;
+		}
+		temp &= ~PORT_LPM;
+		ehci_writel(ehci, temp, portsc);
+		printk(KERN_INFO "disabled LPM for port %lu\n", port);
+	} else
+		return -EOPNOTSUPP;
+	return count;
+}
+
 static inline void create_debug_files (struct ehci_hcd *ehci)
 {
 	struct usb_bus *bus = &ehci_to_hcd(ehci)->self;
···
 	ehci->debug_registers = debugfs_create_file("registers", S_IRUGO,
 						    ehci->debug_dir, bus,
 						    &debug_registers_fops);
+
+	ehci->debug_registers = debugfs_create_file("lpm", S_IRUGO|S_IWUGO,
+						    ehci->debug_dir, bus,
+						    &debug_lpm_fops);
 	if (!ehci->debug_registers)
 		goto registers_error;
 	return;

drivers/usb/host/ehci-hcd.c

···
 #include <linux/dma-mapping.h>
 #include <linux/debugfs.h>
 #include <linux/slab.h>
+#include <linux/uaccess.h>
 
 #include <asm/byteorder.h>
 #include <asm/io.h>

drivers/usb/host/ehci.h

···
 	struct dentry		*debug_async;
 	struct dentry		*debug_periodic;
 	struct dentry		*debug_registers;
+	struct dentry		*debug_lpm;
 #endif
 };
 

include/linux/usb/ehci_def.h

···
 #define HCS_N_PORTS(p)		(((p)>>0)&0xf)	/* bits 3:0, ports on HC */
 
 	u32		hcc_params;      /* HCCPARAMS - offset 0x8 */
+/* EHCI 1.1 addendum */
+#define HCC_32FRAME_PERIODIC_LIST(p)	((p)&(1 << 19))
+#define HCC_PER_PORT_CHANGE_EVENT(p)	((p)&(1 << 18))
+#define HCC_LPM(p)			((p)&(1 << 17))
+#define HCC_HW_PREFETCH(p)		((p)&(1 << 16))
+
 #define HCC_EXT_CAPS(p)		(((p)>>8)&0xff)	/* for pci extended caps */
 #define HCC_ISOC_CACHE(p)       ((p)&(1 << 7))  /* true: can cache isoc frame */
 #define HCC_ISOC_THRES(p)       (((p)>>4)&0x7)  /* bits 6:4, uframes cached */
···
 
 	/* USBCMD: offset 0x00 */
 	u32		command;
+
+/* EHCI 1.1 addendum */
+#define CMD_HIRD	(0xf<<24)	/* host initiated resume duration */
+#define CMD_PPCEE	(1<<15)		/* per port change event enable */
+#define CMD_FSP		(1<<14)		/* fully synchronized prefetch */
+#define CMD_ASPE	(1<<13)		/* async schedule prefetch enable */
+#define CMD_PSPE	(1<<12)		/* periodic schedule prefetch enable */
 /* 23:16 is r/w intr rate, in microframes; default "8" == 1/msec */
 #define CMD_PARK	(1<<11)		/* enable "park" on async qh */
 #define CMD_PARK_CNT(c)	(((c)>>8)&3)	/* how many transfers to park for */
···
 
 	/* USBSTS: offset 0x04 */
 	u32		status;
+#define STS_PPCE_MASK	(0xff<<16)	/* Per-Port change event 1-16 */
 #define STS_ASS		(1<<15)		/* Async Schedule Status */
 #define STS_PSS		(1<<14)		/* Periodic Schedule Status */
 #define STS_RECL	(1<<13)		/* Reclamation */
···
 
 	/* PORTSC: offset 0x44 */
 	u32		port_status[0];	/* up to N_PORTS */
+/* EHCI 1.1 addendum */
+#define PORTSC_SUSPEND_STS_ACK 0
+#define PORTSC_SUSPEND_STS_NYET 1
+#define PORTSC_SUSPEND_STS_STALL 2
+#define PORTSC_SUSPEND_STS_ERR 3
+
+#define PORT_DEV_ADDR	(0x7f<<25)		/* device address */
+#define PORT_SSTS	(0x3<<23)		/* suspend status */
 /* 31:23 reserved */
 #define PORT_WKOC_E	(1<<22)		/* wake on overcurrent (enable) */
 #define PORT_WKDISC_E	(1<<21)		/* wake on disconnect (enable) */
···
 #define PORT_USB11(x) (((x)&(3<<10)) == (1<<10))	/* USB 1.1 device */
 /* 11:10 for detecting lowspeed devices (reset vs release ownership) */
 /* 9 reserved */
+#define PORT_LPM	(1<<9)		/* LPM transaction */
 #define PORT_RESET	(1<<8)		/* reset port */
 #define PORT_SUSPEND	(1<<7)		/* suspend port */
 #define PORT_RESUME	(1<<6)		/* resume it */