firewire: ohci: enable 1394a enhancements

The OHCI spec says that, if the programPhyEnable bit is set, the driver
is responsible for configuring the IEEE1394a enhancements within the PHY
and the link consistently.  So do this.

Also add a quirk to allow disabling these enhancements; this is needed
for the TSB12LV22 where ack accelerations are buggy (erratum b).
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/core.h

@@ -27,8 +27,12 @@ struct fw_packet;
 #define PHY_LINK_ACTIVE		0x80
 #define PHY_CONTENDER		0x40
 #define PHY_BUS_RESET		0x40
+#define PHY_EXTENDED_REGISTERS	0xe0
 #define PHY_BUS_SHORT_RESET	0x40
 #define PHY_INT_STATUS_BITS	0x3c
+#define PHY_ENABLE_ACCEL	0x02
+#define PHY_ENABLE_MULTI	0x01
+#define PHY_PAGE_SELECT		0xe0
 
 #define BANDWIDTH_AVAILABLE_INITIAL	4915
 #define BROADCAST_CHANNEL_INITIAL	(1 << 31 | 31)

drivers/firewire/ohci.c

@@ -236,13 +236,15 @@ static char ohci_driver_name[] = KBUILD_MODNAME;
 #define QUIRK_CYCLE_TIMER		1
 #define QUIRK_RESET_PACKET		2
 #define QUIRK_BE_HEADERS		4
+#define QUIRK_NO_1394A			8
 
 /* In case of multiple matches in ohci_quirks[], only the first one is used. */
 static const struct {
 	unsigned short vendor, device, flags;
 } ohci_quirks[] = {
 	{PCI_VENDOR_ID_TI,	PCI_DEVICE_ID_TI_TSB12LV22, QUIRK_CYCLE_TIMER |
-							    QUIRK_RESET_PACKET},
+							    QUIRK_RESET_PACKET |
+							    QUIRK_NO_1394A},
 	{PCI_VENDOR_ID_TI,	PCI_ANY_ID,	QUIRK_RESET_PACKET},
 	{PCI_VENDOR_ID_AL,	PCI_ANY_ID,	QUIRK_CYCLE_TIMER},
 	{PCI_VENDOR_ID_NEC,	PCI_ANY_ID,	QUIRK_CYCLE_TIMER},
@@ -257,6 +259,7 @@ MODULE_PARM_DESC(quirks, "Chip quirks (default = 0"
 	", nonatomic cycle timer = "	__stringify(QUIRK_CYCLE_TIMER)
 	", reset packet generation = "	__stringify(QUIRK_RESET_PACKET)
 	", AR/selfID endianess = "	__stringify(QUIRK_BE_HEADERS)
+	", no 1394a enhancements = "	__stringify(QUIRK_NO_1394A)
 	")");
 
 #ifdef CONFIG_FIREWIRE_OHCI_DEBUG
@@ -504,6 +507,27 @@ static int ohci_update_phy_reg(struct fw_card *card, int addr,
 	return 0;
 }
 
+static int read_paged_phy_reg(struct fw_card *card,
+			      int page, int addr, u32 *value)
+{
+	struct fw_ohci *ohci = fw_ohci(card);
+	u32 reg;
+	int err;
+
+	err = ohci_update_phy_reg(card, 7, PHY_PAGE_SELECT, page << 5);
+	if (err < 0)
+		return err;
+	flush_writes(ohci);
+	msleep(2);
+	reg = reg_read(ohci, OHCI1394_PhyControl);
+	if ((reg & OHCI1394_PhyControl_WritePending) != 0) {
+		fw_error("failed to write phy reg bits\n");
+		return -EBUSY;
+	}
+
+	return read_phy_reg(card, addr, value);
+}
+
 static int ar_context_add_page(struct ar_context *ctx)
 {
 	struct device *dev = ctx->ohci->card.device;
@@ -1511,13 +1535,64 @@ static void copy_config_rom(__be32 *dest, const __be32 *src, size_t length)
 		memset(&dest[length], 0, CONFIG_ROM_SIZE - size);
 }
 
+static int configure_1394a_enhancements(struct fw_ohci *ohci)
+{
+	bool enable_1394a;
+	u32 reg, phy_compliance;
+	int clear, set, offset;
+
+	/* Check if the driver should configure link and PHY. */
+	if (!(reg_read(ohci, OHCI1394_HCControlSet) &
+	      OHCI1394_HCControl_programPhyEnable))
+		return 0;
+
+	/* Paranoia: check whether the PHY supports 1394a, too. */
+	enable_1394a = false;
+	if (read_phy_reg(&ohci->card, 2, &reg) < 0)
+		return -EIO;
+	if ((reg & PHY_EXTENDED_REGISTERS) == PHY_EXTENDED_REGISTERS) {
+		if (read_paged_phy_reg(&ohci->card, 1, 8, &phy_compliance) < 0)
+			return -EIO;
+		if (phy_compliance >= 1)
+			enable_1394a = true;
+	}
+
+	if (ohci->quirks & QUIRK_NO_1394A)
+		enable_1394a = false;
+
+	/* Configure PHY and link consistently. */
+	if (enable_1394a) {
+		clear = 0;
+		set = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
+	} else {
+		clear = PHY_ENABLE_ACCEL | PHY_ENABLE_MULTI;
+		set = 0;
+	}
+	if (ohci_update_phy_reg(&ohci->card, 5, clear, set) < 0)
+		return -EIO;
+	flush_writes(ohci);
+	msleep(2);
+
+	if (enable_1394a)
+		offset = OHCI1394_HCControlSet;
+	else
+		offset = OHCI1394_HCControlClear;
+	reg_write(ohci, offset, OHCI1394_HCControl_aPhyEnhanceEnable);
+
+	/* Clean up: configuration has been taken care of. */
+	reg_write(ohci, OHCI1394_HCControlClear,
+		  OHCI1394_HCControl_programPhyEnable);
+
+	return 0;
+}
+
 static int ohci_enable(struct fw_card *card,
 		       const __be32 *config_rom, size_t length)
 {
 	struct fw_ohci *ohci = fw_ohci(card);
 	struct pci_dev *dev = to_pci_dev(card->device);
 	u32 lps;
-	int i;
+	int i, err;
 
 	if (software_reset(ohci)) {
 		fw_error("Failed to reset ohci card.\n");
@@ -1581,6 +1656,10 @@ static int ohci_enable(struct fw_card *card,
 	if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
 		reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_busReset);
 
+	err = configure_1394a_enhancements(ohci);
+	if (err < 0)
+		return err;
+
 	/* Activate link_on bit and contender bit in our self ID packets.*/
 	if (ohci_update_phy_reg(card, 4, 0,
 				PHY_LINK_ACTIVE | PHY_CONTENDER) < 0)

drivers/firewire/ohci.h

@@ -67,7 +67,7 @@
 #define   OHCI1394_PhyControl_ReadDone		0x80000000
 #define   OHCI1394_PhyControl_ReadData(r)	(((r) & 0x00ff0000) >> 16)
 #define   OHCI1394_PhyControl_Write(addr, data)	(((addr) << 8) | (data) | 0x00004000)
-#define   OHCI1394_PhyControl_WriteDone		0x00004000
+#define   OHCI1394_PhyControl_WritePending	0x00004000
 #define OHCI1394_IsochronousCycleTimer        0x0F0
 #define OHCI1394_AsReqFilterHiSet             0x100
 #define OHCI1394_AsReqFilterHiClear           0x104