aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorChristian Fetzer <fetzer.ch@gmail.com>2015-11-19 14:13:48 -0500
committerWolfram Sang <wsa@the-dreams.de>2015-11-30 08:36:25 -0500
commit2fee61d22e606fc99ade9079fda15fdee83ec33e (patch)
treed4cc17f9b1f10caf71a2297b4a143f91b5015145
parentca2061e1283b787b49e3f6817645b9f0a2151671 (diff)
i2c: piix4: Add support for multiplexed main adapter in SB800
The SB800 chipset supports a multiplexed main SMBus controller with four ports. The multiplexed ports share the same SMBus address and register set. The port is selected by bits 2:1 of the smb_en register (0x2C). Only one port can be active at any point in time therefore a mutex is needed in order to synchronize access. Additionally, the commit avoids requesting and releasing the SMBus base address index region on every multiplexed transfer by moving the request_region call into piix4_probe. Tested on HP ProLiant MicroServer G7 N54L (where this patch adds support to access sensor data from the w83795adg). Cc: Thomas Brandon <tbrandonau@gmail.com> Cc: Eddi De Pieri <eddi@depieri.net> Signed-off-by: Christian Fetzer <fetzer.ch@gmail.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
-rw-r--r--drivers/i2c/busses/i2c-piix4.c169
1 files changed, 147 insertions, 22 deletions
diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 9c32eb124b72..6b4231d406d5 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -23,6 +23,9 @@
23 23
24 Note: we assume there can only be one device, with one or more 24 Note: we assume there can only be one device, with one or more
25 SMBus interfaces. 25 SMBus interfaces.
26 The device can register multiple i2c_adapters (up to PIIX4_MAX_ADAPTERS).
27 For devices supporting multiple ports the i2c_adapter should provide
28 an i2c_algorithm to access them.
26*/ 29*/
27 30
28#include <linux/module.h> 31#include <linux/module.h>
@@ -37,6 +40,7 @@
37#include <linux/dmi.h> 40#include <linux/dmi.h>
38#include <linux/acpi.h> 41#include <linux/acpi.h>
39#include <linux/io.h> 42#include <linux/io.h>
43#include <linux/mutex.h>
40 44
41 45
42/* PIIX4 SMBus address offsets */ 46/* PIIX4 SMBus address offsets */
@@ -78,6 +82,13 @@
78/* Multi-port constants */ 82/* Multi-port constants */
79#define PIIX4_MAX_ADAPTERS 4 83#define PIIX4_MAX_ADAPTERS 4
80 84
85/* SB800 constants */
86#define SB800_PIIX4_SMB_IDX 0xcd6
87
88/* SB800 port is selected by bits 2:1 of the smb_en register (0x2c) */
89#define SB800_PIIX4_PORT_IDX 0x2c
90#define SB800_PIIX4_PORT_IDX_MASK 0x06
91
81/* insmod parameters */ 92/* insmod parameters */
82 93
83/* If force is set to anything different from 0, we forcibly enable the 94/* If force is set to anything different from 0, we forcibly enable the
@@ -127,6 +138,11 @@ static const struct dmi_system_id piix4_dmi_ibm[] = {
127 138
128struct i2c_piix4_adapdata { 139struct i2c_piix4_adapdata {
129 unsigned short smba; 140 unsigned short smba;
141
142 /* SB800 */
143 bool sb800_main;
144 unsigned short port;
145 struct mutex *mutex;
130}; 146};
131 147
132static int piix4_setup(struct pci_dev *PIIX4_dev, 148static int piix4_setup(struct pci_dev *PIIX4_dev,
@@ -232,7 +248,6 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
232 const struct pci_device_id *id, u8 aux) 248 const struct pci_device_id *id, u8 aux)
233{ 249{
234 unsigned short piix4_smba; 250 unsigned short piix4_smba;
235 unsigned short smba_idx = 0xcd6;
236 u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status; 251 u8 smba_en_lo, smba_en_hi, smb_en, smb_en_status;
237 u8 i2ccfg, i2ccfg_offset = 0x10; 252 u8 i2ccfg, i2ccfg_offset = 0x10;
238 253
@@ -254,16 +269,10 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
254 else 269 else
255 smb_en = (aux) ? 0x28 : 0x2c; 270 smb_en = (aux) ? 0x28 : 0x2c;
256 271
257 if (!request_region(smba_idx, 2, "smba_idx")) { 272 outb_p(smb_en, SB800_PIIX4_SMB_IDX);
258 dev_err(&PIIX4_dev->dev, "SMBus base address index region " 273 smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
259 "0x%x already in use!\n", smba_idx); 274 outb_p(smb_en + 1, SB800_PIIX4_SMB_IDX);
260 return -EBUSY; 275 smba_en_hi = inb_p(SB800_PIIX4_SMB_IDX + 1);
261 }
262 outb_p(smb_en, smba_idx);
263 smba_en_lo = inb_p(smba_idx + 1);
264 outb_p(smb_en + 1, smba_idx);
265 smba_en_hi = inb_p(smba_idx + 1);
266 release_region(smba_idx, 2);
267 276
268 if (!smb_en) { 277 if (!smb_en) {
269 smb_en_status = smba_en_lo & 0x10; 278 smb_en_status = smba_en_lo & 0x10;
@@ -527,6 +536,43 @@ static s32 piix4_access(struct i2c_adapter * adap, u16 addr,
527 return 0; 536 return 0;
528} 537}
529 538
539/*
540 * Handles access to multiple SMBus ports on the SB800.
541 * The port is selected by bits 2:1 of the smb_en register (0x2c).
542 * Returns negative errno on error.
543 *
544 * Note: The selected port must be returned to the initial selection to avoid
545 * problems on certain systems.
546 */
547static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
548 unsigned short flags, char read_write,
549 u8 command, int size, union i2c_smbus_data *data)
550{
551 struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
552 u8 smba_en_lo;
553 u8 port;
554 int retval;
555
556 mutex_lock(adapdata->mutex);
557
558 outb_p(SB800_PIIX4_PORT_IDX, SB800_PIIX4_SMB_IDX);
559 smba_en_lo = inb_p(SB800_PIIX4_SMB_IDX + 1);
560
561 port = adapdata->port;
562 if ((smba_en_lo & SB800_PIIX4_PORT_IDX_MASK) != (port << 1))
563 outb_p((smba_en_lo & ~SB800_PIIX4_PORT_IDX_MASK) | (port << 1),
564 SB800_PIIX4_SMB_IDX + 1);
565
566 retval = piix4_access(adap, addr, flags, read_write,
567 command, size, data);
568
569 outb_p(smba_en_lo, SB800_PIIX4_SMB_IDX + 1);
570
571 mutex_unlock(adapdata->mutex);
572
573 return retval;
574}
575
530static u32 piix4_func(struct i2c_adapter *adapter) 576static u32 piix4_func(struct i2c_adapter *adapter)
531{ 577{
532 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 578 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
@@ -539,6 +585,11 @@ static const struct i2c_algorithm smbus_algorithm = {
539 .functionality = piix4_func, 585 .functionality = piix4_func,
540}; 586};
541 587
588static const struct i2c_algorithm piix4_smbus_algorithm_sb800 = {
589 .smbus_xfer = piix4_access_sb800,
590 .functionality = piix4_func,
591};
592
542static const struct pci_device_id piix4_ids[] = { 593static const struct pci_device_id piix4_ids[] = {
543 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) }, 594 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371AB_3) },
544 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) }, 595 { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82443MX_3) },
@@ -614,6 +665,53 @@ static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
614 return 0; 665 return 0;
615} 666}
616 667
668static int piix4_add_adapters_sb800(struct pci_dev *dev, unsigned short smba)
669{
670 struct mutex *mutex;
671 struct i2c_piix4_adapdata *adapdata;
672 int port;
673 int retval;
674
675 mutex = kzalloc(sizeof(*mutex), GFP_KERNEL);
676 if (mutex == NULL)
677 return -ENOMEM;
678
679 mutex_init(mutex);
680
681 for (port = 0; port < PIIX4_MAX_ADAPTERS; port++) {
682 retval = piix4_add_adapter(dev, smba,
683 &piix4_main_adapters[port]);
684 if (retval < 0)
685 goto error;
686
687 piix4_main_adapters[port]->algo = &piix4_smbus_algorithm_sb800;
688
689 adapdata = i2c_get_adapdata(piix4_main_adapters[port]);
690 adapdata->sb800_main = true;
691 adapdata->port = port;
692 adapdata->mutex = mutex;
693 }
694
695 return retval;
696
697error:
698 dev_err(&dev->dev,
699 "Error setting up SB800 adapters. Unregistering!\n");
700 while (--port >= 0) {
701 adapdata = i2c_get_adapdata(piix4_main_adapters[port]);
702 if (adapdata->smba) {
703 i2c_del_adapter(piix4_main_adapters[port]);
704 kfree(adapdata);
705 kfree(piix4_main_adapters[port]);
706 piix4_main_adapters[port] = NULL;
707 }
708 }
709
710 kfree(mutex);
711
712 return retval;
713}
714
617static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id) 715static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
618{ 716{
619 int retval; 717 int retval;
@@ -621,20 +719,41 @@ static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
621 if ((dev->vendor == PCI_VENDOR_ID_ATI && 719 if ((dev->vendor == PCI_VENDOR_ID_ATI &&
622 dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS && 720 dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
623 dev->revision >= 0x40) || 721 dev->revision >= 0x40) ||
624 dev->vendor == PCI_VENDOR_ID_AMD) 722 dev->vendor == PCI_VENDOR_ID_AMD) {
723 if (!request_region(SB800_PIIX4_SMB_IDX, 2, "smba_idx")) {
724 dev_err(&dev->dev,
725 "SMBus base address index region 0x%x already in use!\n",
726 SB800_PIIX4_SMB_IDX);
727 return -EBUSY;
728 }
729
625 /* base address location etc changed in SB800 */ 730 /* base address location etc changed in SB800 */
626 retval = piix4_setup_sb800(dev, id, 0); 731 retval = piix4_setup_sb800(dev, id, 0);
627 else 732 if (retval < 0) {
628 retval = piix4_setup(dev, id); 733 release_region(SB800_PIIX4_SMB_IDX, 2);
734 return retval;
735 }
629 736
630 /* If no main SMBus found, give up */ 737 /*
631 if (retval < 0) 738 * Try to register multiplexed main SMBus adapter,
632 return retval; 739 * give up if we can't
740 */
741 retval = piix4_add_adapters_sb800(dev, retval);
742 if (retval < 0) {
743 release_region(SB800_PIIX4_SMB_IDX, 2);
744 return retval;
745 }
746 } else {
747 retval = piix4_setup(dev, id);
748 if (retval < 0)
749 return retval;
633 750
634 /* Try to register main SMBus adapter, give up if we can't */ 751 /* Try to register main SMBus adapter, give up if we can't */
635 retval = piix4_add_adapter(dev, retval, &piix4_main_adapters[0]); 752 retval = piix4_add_adapter(dev, retval,
636 if (retval < 0) 753 &piix4_main_adapters[0]);
637 return retval; 754 if (retval < 0)
755 return retval;
756 }
638 757
639 /* Check for auxiliary SMBus on some AMD chipsets */ 758 /* Check for auxiliary SMBus on some AMD chipsets */
640 retval = -ENODEV; 759 retval = -ENODEV;
@@ -669,7 +788,13 @@ static void piix4_adap_remove(struct i2c_adapter *adap)
669 788
670 if (adapdata->smba) { 789 if (adapdata->smba) {
671 i2c_del_adapter(adap); 790 i2c_del_adapter(adap);
672 release_region(adapdata->smba, SMBIOSIZE); 791 if (adapdata->port == 0) {
792 release_region(adapdata->smba, SMBIOSIZE);
793 if (adapdata->sb800_main) {
794 kfree(adapdata->mutex);
795 release_region(SB800_PIIX4_SMB_IDX, 2);
796 }
797 }
673 kfree(adapdata); 798 kfree(adapdata);
674 kfree(adap); 799 kfree(adap);
675 } 800 }