[C] [PATCH 7/8] i2c: Add drivers for the AMD PCIe MP2 I2C controller
Kai-Heng Feng
kai.heng.feng at canonical.com
Tue Apr 2 03:38:42 UTC 2019
From: Elie Morisse <syniurge at gmail.com>
BugLink: https://bugs.launchpad.net/bugs/1787775
MP2 controllers have two separate busses, so may accommodate up to two I2C
adapters. Those adapters are listed in the ACPI namespace with the
"AMDI0011" HID, and probed by a platform driver.
Communication with the MP2 takes place through MMIO registers, or through
DMA for more than 32 bytes transfers.
This is major rework of the patch submitted by Nehal-bakulchandra Shah from
AMD (https://patchwork.kernel.org/patch/10597369/).
Most of the event handling of v3 was rewritten to make it work with more
than one bus (e.g on Ryzen-based Lenovo Yoga 530), and this version
contains many other improvements.
Signed-off-by: Elie Morisse <syniurge at gmail.com>
Signed-off-by: Wolfram Sang <wsa at the-dreams.de>
(backported from commit 529766e0a0114438887382a68d97341fbf8349fb linux-next)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
Documentation/i2c/busses/i2c-amd-mp2 | 23 ++
MAINTAINERS | 8 +
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-amd-mp2-pci.c | 483 ++++++++++++++++++++++++++
drivers/i2c/busses/i2c-amd-mp2-plat.c | 367 +++++++++++++++++++
drivers/i2c/busses/i2c-amd-mp2.h | 219 ++++++++++++
7 files changed, 1111 insertions(+)
create mode 100644 Documentation/i2c/busses/i2c-amd-mp2
create mode 100644 drivers/i2c/busses/i2c-amd-mp2-pci.c
create mode 100644 drivers/i2c/busses/i2c-amd-mp2-plat.c
create mode 100644 drivers/i2c/busses/i2c-amd-mp2.h
diff --git a/Documentation/i2c/busses/i2c-amd-mp2 b/Documentation/i2c/busses/i2c-amd-mp2
new file mode 100644
index 000000000000..6571487171f4
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-amd-mp2
@@ -0,0 +1,23 @@
+Kernel driver i2c-amd-mp2
+
+Supported adapters:
+ * AMD MP2 PCIe interface
+
+Datasheet: not publicly available.
+
+Authors:
+ Shyam Sundar S K <Shyam-sundar.S-k at amd.com>
+ Nehal Shah <nehal-bakulchandra.shah at amd.com>
+ Elie Morisse <syniurge at gmail.com>
+
+Description
+-----------
+
+The MP2 is an ARM processor programmed as an I2C controller and communicating
+with the x86 host through PCI.
+
+If you see something like this:
+
+03:00.7 MP2 I2C controller: Advanced Micro Devices, Inc. [AMD] Device 15e6
+
+in your 'lspci -v', then this driver is for your device.
diff --git a/MAINTAINERS b/MAINTAINERS
index e21c58a827b0..ef166b53a5a7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -777,6 +777,14 @@ F: drivers/gpu/drm/amd/include/vi_structs.h
F: drivers/gpu/drm/amd/include/v9_structs.h
F: include/uapi/linux/kfd_ioctl.h
+AMD MP2 I2C DRIVER
+M: Elie Morisse <syniurge at gmail.com>
+M: Nehal Shah <nehal-bakulchandra.shah at amd.com>
+M: Shyam Sundar S K <shyam-sundar.s-k at amd.com>
+L: linux-i2c at vger.kernel.org
+S: Maintained
+F: drivers/i2c/busses/i2c-amd-mp2*
+
AMD SEATTLE DEVICE TREE SUPPORT
M: Brijesh Singh <brijeshkumar.singh at amd.com>
M: Suravee Suthikulpanit <suravee.suthikulpanit at amd.com>
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 033958bcdd4b..8fefa5d4d252 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -77,6 +77,16 @@ config I2C_AMD8111
This driver can also be built as a module. If so, the module
will be called i2c-amd8111.
+config I2C_AMD_MP2
+ tristate "AMD MP2 PCIe"
+ depends on PCI && ACPI
+ help
+ If you say yes to this option, support will be included for the AMD
+ MP2 PCIe I2C adapter.
+
+ This driver can also be built as modules. If so, the modules will
+ be called i2c-amd-mp2-pci and i2c-amd-mp2-plat.
+
config I2C_HIX5HD2
tristate "Hix5hd2 high-speed I2C driver"
depends on ARCH_HISI || ARCH_HIX5HD2 || COMPILE_TEST
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index d6e48ec3372a..930142bf4f32 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o
# Embedded system I2C/SMBus host controller drivers
obj-$(CONFIG_I2C_ALTERA) += i2c-altera.o
+obj-$(CONFIG_I2C_AMD_MP2) += i2c-amd-mp2-pci.o i2c-amd-mp2-plat.o
obj-$(CONFIG_I2C_ASPEED) += i2c-aspeed.o
obj-$(CONFIG_I2C_AT91) += i2c-at91.o
obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
diff --git a/drivers/i2c/busses/i2c-amd-mp2-pci.c b/drivers/i2c/busses/i2c-amd-mp2-pci.c
new file mode 100644
index 000000000000..455e1f36a2a3
--- /dev/null
+++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c
@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * AMD MP2 PCIe communication driver
+ *
+ * Authors: Shyam Sundar S K <Shyam-sundar.S-k at amd.com>
+ * Elie Morisse <syniurge at gmail.com>
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include "i2c-amd-mp2.h"
+
+#include <linux/io-64-nonatomic-lo-hi.h>
+
+static void amd_mp2_c2p_mutex_lock(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ /* there is only one data mailbox for two i2c adapters */
+ mutex_lock(&privdata->c2p_lock);
+ privdata->c2p_lock_busid = i2c_common->bus_id;
+}
+
+static void amd_mp2_c2p_mutex_unlock(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ if (unlikely(privdata->c2p_lock_busid != i2c_common->bus_id)) {
+ dev_warn(ndev_dev(privdata),
+ "bus %d attempting to unlock C2P locked by bus %d\n",
+ i2c_common->bus_id, privdata->c2p_lock_busid);
+ return;
+ }
+
+ mutex_unlock(&privdata->c2p_lock);
+}
+
+static int amd_mp2_cmd(struct amd_i2c_common *i2c_common,
+ union i2c_cmd_base i2c_cmd_base)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ void __iomem *reg;
+
+ i2c_common->reqcmd = i2c_cmd_base.s.i2c_cmd;
+
+ reg = privdata->mmio + ((i2c_cmd_base.s.bus_id == 1) ?
+ AMD_C2P_MSG1 : AMD_C2P_MSG0);
+ writel(i2c_cmd_base.ul, reg);
+
+ return 0;
+}
+
+int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ union i2c_cmd_base i2c_cmd_base;
+
+ dev_dbg(ndev_dev(privdata), "%s id: %d\n", __func__,
+ i2c_common->bus_id);
+
+ i2c_cmd_base.ul = 0;
+ i2c_cmd_base.s.i2c_cmd = enable ? i2c_enable : i2c_disable;
+ i2c_cmd_base.s.bus_id = i2c_common->bus_id;
+ i2c_cmd_base.s.i2c_speed = i2c_common->i2c_speed;
+
+ amd_mp2_c2p_mutex_lock(i2c_common);
+
+ return amd_mp2_cmd(i2c_common, i2c_cmd_base);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_bus_enable_set);
+
+static void amd_mp2_cmd_rw_fill(struct amd_i2c_common *i2c_common,
+ union i2c_cmd_base *i2c_cmd_base,
+ enum i2c_cmd reqcmd)
+{
+ i2c_cmd_base->s.i2c_cmd = reqcmd;
+ i2c_cmd_base->s.bus_id = i2c_common->bus_id;
+ i2c_cmd_base->s.i2c_speed = i2c_common->i2c_speed;
+ i2c_cmd_base->s.slave_addr = i2c_common->msg->addr;
+ i2c_cmd_base->s.length = i2c_common->msg->len;
+}
+
+int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ union i2c_cmd_base i2c_cmd_base;
+
+ amd_mp2_cmd_rw_fill(i2c_common, &i2c_cmd_base, reqcmd);
+ amd_mp2_c2p_mutex_lock(i2c_common);
+
+ if (i2c_common->msg->len <= 32) {
+ i2c_cmd_base.s.mem_type = use_c2pmsg;
+ if (reqcmd == i2c_write)
+ memcpy_toio(privdata->mmio + AMD_C2P_MSG2,
+ i2c_common->msg->buf,
+ i2c_common->msg->len);
+ } else {
+ i2c_cmd_base.s.mem_type = use_dram;
+ writeq((u64)i2c_common->dma_addr,
+ privdata->mmio + AMD_C2P_MSG2);
+ }
+
+ return amd_mp2_cmd(i2c_common, i2c_cmd_base);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_rw);
+
+static void amd_mp2_pci_check_rw_event(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ int len = i2c_common->eventval.r.length;
+ u32 slave_addr = i2c_common->eventval.r.slave_addr;
+ bool err = false;
+
+ if (unlikely(len != i2c_common->msg->len)) {
+ dev_err(ndev_dev(privdata),
+ "length %d in event doesn't match buffer length %d!\n",
+ len, i2c_common->msg->len);
+ err = true;
+ }
+
+ if (unlikely(slave_addr != i2c_common->msg->addr)) {
+ dev_err(ndev_dev(privdata),
+ "unexpected slave address %x (expected: %x)!\n",
+ slave_addr, i2c_common->msg->addr);
+ err = true;
+ }
+
+ if (!err)
+ i2c_common->cmd_success = true;
+}
+
+static void __amd_mp2_process_event(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ enum status_type sts = i2c_common->eventval.r.status;
+ enum response_type res = i2c_common->eventval.r.response;
+ int len = i2c_common->eventval.r.length;
+
+ if (res != command_success) {
+ if (res != command_failed)
+ dev_err(ndev_dev(privdata), "invalid response to i2c command!\n");
+ return;
+ }
+
+ switch (i2c_common->reqcmd) {
+ case i2c_read:
+ if (sts == i2c_readcomplete_event) {
+ amd_mp2_pci_check_rw_event(i2c_common);
+ if (len <= 32)
+ memcpy_fromio(i2c_common->msg->buf,
+ privdata->mmio + AMD_C2P_MSG2,
+ len);
+ } else if (sts != i2c_readfail_event) {
+ dev_err(ndev_dev(privdata),
+ "invalid i2c status after read (%d)!\n", sts);
+ }
+ break;
+ case i2c_write:
+ if (sts == i2c_writecomplete_event)
+ amd_mp2_pci_check_rw_event(i2c_common);
+ else if (sts != i2c_writefail_event)
+ dev_err(ndev_dev(privdata),
+ "invalid i2c status after write (%d)!\n", sts);
+ break;
+ case i2c_enable:
+ if (sts == i2c_busenable_complete)
+ i2c_common->cmd_success = true;
+ else if (sts != i2c_busenable_failed)
+ dev_err(ndev_dev(privdata),
+ "invalid i2c status after bus enable (%d)!\n",
+ sts);
+ break;
+ case i2c_disable:
+ if (sts == i2c_busdisable_complete)
+ i2c_common->cmd_success = true;
+ else if (sts != i2c_busdisable_failed)
+ dev_err(ndev_dev(privdata),
+ "invalid i2c status after bus disable (%d)!\n",
+ sts);
+ break;
+ default:
+ break;
+ }
+}
+
+void amd_mp2_process_event(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ if (unlikely(i2c_common->reqcmd == i2c_none)) {
+ dev_warn(ndev_dev(privdata),
+ "received msg but no cmd was sent (bus = %d)!\n",
+ i2c_common->bus_id);
+ return;
+ }
+
+ __amd_mp2_process_event(i2c_common);
+
+ i2c_common->reqcmd = i2c_none;
+ amd_mp2_c2p_mutex_unlock(i2c_common);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_process_event);
+
+static irqreturn_t amd_mp2_irq_isr(int irq, void *dev)
+{
+ struct amd_mp2_dev *privdata = dev;
+ struct amd_i2c_common *i2c_common;
+ u32 val;
+ unsigned int bus_id;
+ void __iomem *reg;
+ enum irqreturn ret = IRQ_NONE;
+
+ for (bus_id = 0; bus_id < 2; bus_id++) {
+ i2c_common = privdata->busses[bus_id];
+ if (!i2c_common)
+ continue;
+
+ reg = privdata->mmio + ((bus_id == 0) ?
+ AMD_P2C_MSG1 : AMD_P2C_MSG2);
+ val = readl(reg);
+ if (val != 0) {
+ writel(0, reg);
+ writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+ i2c_common->eventval.ul = val;
+ i2c_common->cmd_completion(i2c_common);
+
+ ret = IRQ_HANDLED;
+ }
+ }
+
+ if (ret != IRQ_HANDLED) {
+ val = readl(privdata->mmio + AMD_P2C_MSG_INTEN);
+ if (val != 0) {
+ writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+ dev_warn(ndev_dev(privdata),
+ "received irq without message\n");
+ ret = IRQ_HANDLED;
+ }
+ }
+
+ return ret;
+}
+
+void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common)
+{
+ i2c_common->reqcmd = i2c_none;
+ amd_mp2_c2p_mutex_unlock(i2c_common);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_rw_timeout);
+
+int amd_mp2_register_cb(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ if (i2c_common->bus_id > 1)
+ return -EINVAL;
+
+ if (privdata->busses[i2c_common->bus_id]) {
+ dev_err(ndev_dev(privdata),
+ "Bus %d already taken!\n", i2c_common->bus_id);
+ return -EINVAL;
+ }
+
+ privdata->busses[i2c_common->bus_id] = i2c_common;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(amd_mp2_register_cb);
+
+int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ privdata->busses[i2c_common->bus_id] = NULL;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(amd_mp2_unregister_cb);
+
+static void amd_mp2_clear_reg(struct amd_mp2_dev *privdata)
+{
+ int reg;
+
+ for (reg = AMD_C2P_MSG0; reg <= AMD_C2P_MSG9; reg += 4)
+ writel(0, privdata->mmio + reg);
+
+ for (reg = AMD_P2C_MSG1; reg <= AMD_P2C_MSG2; reg += 4)
+ writel(0, privdata->mmio + reg);
+}
+
+static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
+ struct pci_dev *pci_dev)
+{
+ int rc;
+
+ pci_set_drvdata(pci_dev, privdata);
+
+ rc = pcim_enable_device(pci_dev);
+ if (rc) {
+ dev_err(ndev_dev(privdata), "Failed to enable MP2 PCI device\n");
+ goto err_pci_enable;
+ }
+
+ rc = pcim_iomap_regions(pci_dev, 1 << 2, pci_name(pci_dev));
+ if (rc) {
+ dev_err(ndev_dev(privdata), "I/O memory remapping failed\n");
+ goto err_pci_enable;
+ }
+ privdata->mmio = pcim_iomap_table(pci_dev)[2];
+
+ pci_set_master(pci_dev);
+
+ rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(64));
+ if (rc) {
+ rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
+ if (rc)
+ goto err_dma_mask;
+ }
+
+ /* Set up intx irq */
+ writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+ pci_intx(pci_dev, 1);
+ rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_mp2_irq_isr,
+ IRQF_SHARED, dev_name(&pci_dev->dev), privdata);
+ if (rc)
+ dev_err(&pci_dev->dev, "Failure requesting irq %i: %d\n",
+ pci_dev->irq, rc);
+
+ return rc;
+
+err_dma_mask:
+ pci_clear_master(pci_dev);
+err_pci_enable:
+ pci_set_drvdata(pci_dev, NULL);
+ return rc;
+}
+
+static int amd_mp2_pci_probe(struct pci_dev *pci_dev,
+ const struct pci_device_id *id)
+{
+ struct amd_mp2_dev *privdata;
+ int rc;
+
+ privdata = devm_kzalloc(&pci_dev->dev, sizeof(*privdata), GFP_KERNEL);
+ if (!privdata)
+ return -ENOMEM;
+
+ rc = amd_mp2_pci_init(privdata, pci_dev);
+ if (rc)
+ return rc;
+
+ mutex_init(&privdata->c2p_lock);
+ privdata->pci_dev = pci_dev;
+
+ pm_runtime_set_autosuspend_delay(&pci_dev->dev, 1000);
+ pm_runtime_use_autosuspend(&pci_dev->dev);
+ pm_runtime_put_autosuspend(&pci_dev->dev);
+ pm_runtime_allow(&pci_dev->dev);
+
+ privdata->probed = true;
+
+ dev_info(&pci_dev->dev, "MP2 device registered.\n");
+ return 0;
+}
+
+static void amd_mp2_pci_remove(struct pci_dev *pci_dev)
+{
+ struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
+
+ pm_runtime_forbid(&pci_dev->dev);
+ pm_runtime_get_noresume(&pci_dev->dev);
+
+ pci_intx(pci_dev, 0);
+ pci_clear_master(pci_dev);
+
+ amd_mp2_clear_reg(privdata);
+}
+
+#ifdef CONFIG_PM
+static int amd_mp2_pci_suspend(struct device *dev)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
+ struct amd_i2c_common *i2c_common;
+ unsigned int bus_id;
+ int ret = 0;
+
+ for (bus_id = 0; bus_id < 2; bus_id++) {
+ i2c_common = privdata->busses[bus_id];
+ if (i2c_common)
+ i2c_common->suspend(i2c_common);
+ }
+
+ ret = pci_save_state(pci_dev);
+ if (ret) {
+ dev_err(ndev_dev(privdata),
+ "pci_save_state failed = %d\n", ret);
+ return ret;
+ }
+
+ pci_disable_device(pci_dev);
+ return ret;
+}
+
+static int amd_mp2_pci_resume(struct device *dev)
+{
+ struct pci_dev *pci_dev = to_pci_dev(dev);
+ struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
+ struct amd_i2c_common *i2c_common;
+ unsigned int bus_id;
+ int ret = 0;
+
+ pci_restore_state(pci_dev);
+ ret = pci_enable_device(pci_dev);
+ if (ret < 0) {
+ dev_err(ndev_dev(privdata),
+ "pci_enable_device failed = %d\n", ret);
+ return ret;
+ }
+
+ for (bus_id = 0; bus_id < 2; bus_id++) {
+ i2c_common = privdata->busses[bus_id];
+ if (i2c_common) {
+ ret = i2c_common->resume(i2c_common);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+static UNIVERSAL_DEV_PM_OPS(amd_mp2_pci_pm_ops, amd_mp2_pci_suspend,
+ amd_mp2_pci_resume, NULL);
+#endif /* CONFIG_PM */
+
+static const struct pci_device_id amd_mp2_pci_tbl[] = {
+ {PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2)},
+ {0}
+};
+MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl);
+
+static struct pci_driver amd_mp2_pci_driver = {
+ .name = "i2c_amd_mp2",
+ .id_table = amd_mp2_pci_tbl,
+ .probe = amd_mp2_pci_probe,
+ .remove = amd_mp2_pci_remove,
+#ifdef CONFIG_PM
+ .driver = {
+ .pm = &amd_mp2_pci_pm_ops,
+ },
+#endif
+};
+module_pci_driver(amd_mp2_pci_driver);
+
+static int amd_mp2_device_match(struct device *dev, void *data)
+{
+ return 1;
+}
+
+struct amd_mp2_dev *amd_mp2_find_device(void)
+{
+ struct device *dev;
+ struct pci_dev *pci_dev;
+
+ dev = driver_find_device(&amd_mp2_pci_driver.driver, NULL, NULL,
+ amd_mp2_device_match);
+ if (!dev)
+ return NULL;
+
+ pci_dev = to_pci_dev(dev);
+ return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_find_device);
+
+MODULE_DESCRIPTION("AMD(R) PCI-E MP2 I2C Controller Driver");
+MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k at amd.com>");
+MODULE_AUTHOR("Elie Morisse <syniurge at gmail.com>");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/i2c/busses/i2c-amd-mp2-plat.c b/drivers/i2c/busses/i2c-amd-mp2-plat.c
new file mode 100644
index 000000000000..f5b3f00c6559
--- /dev/null
+++ b/drivers/i2c/busses/i2c-amd-mp2-plat.c
@@ -0,0 +1,367 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * AMD MP2 platform driver
+ *
+ * Setup the I2C adapters enumerated in the ACPI namespace.
+ * MP2 controllers have 2 separate busses, up to 2 I2C adapters may be listed.
+ *
+ * Authors: Nehal Bakulchandra Shah <Nehal-bakulchandra.shah at amd.com>
+ * Elie Morisse <syniurge at gmail.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "i2c-amd-mp2.h"
+
+#define AMD_MP2_I2C_MAX_RW_LENGTH ((1 << 12) - 1)
+#define AMD_I2C_TIMEOUT (msecs_to_jiffies(250))
+
+/**
+ * struct amd_i2c_dev - MP2 bus/i2c adapter context
+ * @common: shared context with the MP2 PCI driver
+ * @pdev: platform driver node
+ * @adap: i2c adapter
+ * @cmd_complete: xfer completion object
+ */
+struct amd_i2c_dev {
+ struct amd_i2c_common common;
+ struct platform_device *pdev;
+ struct i2c_adapter adap;
+ struct completion cmd_complete;
+};
+
+#define amd_i2c_dev_common(__common) \
+ container_of(__common, struct amd_i2c_dev, common)
+
+static int i2c_amd_dma_map(struct amd_i2c_common *i2c_common)
+{
+ struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;
+ struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
+ enum dma_data_direction dma_direction =
+ i2c_common->msg->flags & I2C_M_RD ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+ i2c_common->dma_buf = i2c_get_dma_safe_msg_buf(i2c_common->msg, 0);
+ i2c_common->dma_addr = dma_map_single(dev_pci, i2c_common->dma_buf,
+ i2c_common->msg->len,
+ dma_direction);
+
+ if (unlikely(dma_mapping_error(dev_pci, i2c_common->dma_addr))) {
+ dev_err(&i2c_dev->pdev->dev,
+ "Error while mapping dma buffer %p\n",
+ i2c_common->dma_buf);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static void i2c_amd_dma_unmap(struct amd_i2c_common *i2c_common)
+{
+ struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;
+ enum dma_data_direction dma_direction =
+ i2c_common->msg->flags & I2C_M_RD ?
+ DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+ dma_unmap_single(dev_pci, i2c_common->dma_addr,
+ i2c_common->msg->len, dma_direction);
+
+ i2c_release_dma_safe_msg_buf(i2c_common->msg, i2c_common->dma_buf);
+}
+
+static void i2c_amd_start_cmd(struct amd_i2c_dev *i2c_dev)
+{
+ struct amd_i2c_common *i2c_common = &i2c_dev->common;
+
+ reinit_completion(&i2c_dev->cmd_complete);
+ i2c_common->cmd_success = false;
+}
+
+static void i2c_amd_cmd_completion(struct amd_i2c_common *i2c_common)
+{
+ struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
+ union i2c_event *event = &i2c_common->eventval;
+
+ if (event->r.status == i2c_readcomplete_event)
+ dev_dbg(&i2c_dev->pdev->dev, "%s readdata:%*ph\n",
+ __func__, event->r.length,
+ i2c_common->msg->buf);
+
+ complete(&i2c_dev->cmd_complete);
+}
+
+static int i2c_amd_check_cmd_completion(struct amd_i2c_dev *i2c_dev)
+{
+ struct amd_i2c_common *i2c_common = &i2c_dev->common;
+ unsigned long timeout;
+
+ timeout = wait_for_completion_timeout(&i2c_dev->cmd_complete,
+ i2c_dev->adap.timeout);
+
+ if ((i2c_common->reqcmd == i2c_read ||
+ i2c_common->reqcmd == i2c_write) &&
+ i2c_common->msg->len > 32)
+ i2c_amd_dma_unmap(i2c_common);
+
+ if (timeout == 0) {
+ amd_mp2_rw_timeout(i2c_common);
+ return -ETIMEDOUT;
+ }
+
+ amd_mp2_process_event(i2c_common);
+
+ if (!i2c_common->cmd_success)
+ return -EIO;
+
+ return 0;
+}
+
+static int i2c_amd_enable_set(struct amd_i2c_dev *i2c_dev, bool enable)
+{
+ struct amd_i2c_common *i2c_common = &i2c_dev->common;
+
+ i2c_amd_start_cmd(i2c_dev);
+ amd_mp2_bus_enable_set(i2c_common, enable);
+
+ return i2c_amd_check_cmd_completion(i2c_dev);
+}
+
+static int i2c_amd_xfer_msg(struct amd_i2c_dev *i2c_dev, struct i2c_msg *pmsg)
+{
+ struct amd_i2c_common *i2c_common = &i2c_dev->common;
+
+ i2c_amd_start_cmd(i2c_dev);
+ i2c_common->msg = pmsg;
+
+ if (pmsg->len > 32)
+ if (i2c_amd_dma_map(i2c_common))
+ return -EIO;
+
+ if (pmsg->flags & I2C_M_RD)
+ amd_mp2_rw(i2c_common, i2c_read);
+ else
+ amd_mp2_rw(i2c_common, i2c_write);
+
+ return i2c_amd_check_cmd_completion(i2c_dev);
+}
+
+static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+ int i;
+ struct i2c_msg *pmsg;
+ int err;
+
+ /* the adapter might have been deleted while waiting for the bus lock */
+ if (unlikely(!i2c_dev->common.mp2_dev))
+ return -EINVAL;
+
+ amd_mp2_pm_runtime_get(i2c_dev->common.mp2_dev);
+
+ for (i = 0; i < num; i++) {
+ pmsg = &msgs[i];
+ err = i2c_amd_xfer_msg(i2c_dev, pmsg);
+ if (err)
+ break;
+ }
+
+ amd_mp2_pm_runtime_put(i2c_dev->common.mp2_dev);
+ return err ? err : num;
+}
+
+static u32 i2c_amd_func(struct i2c_adapter *a)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm i2c_amd_algorithm = {
+ .master_xfer = i2c_amd_xfer,
+ .functionality = i2c_amd_func,
+};
+
+#ifdef CONFIG_PM
+static int i2c_amd_suspend(struct amd_i2c_common *i2c_common)
+{
+ struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
+
+ i2c_amd_enable_set(i2c_dev, false);
+ return 0;
+}
+
+static int i2c_amd_resume(struct amd_i2c_common *i2c_common)
+{
+ struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
+
+ return i2c_amd_enable_set(i2c_dev, true);
+}
+#endif
+
+static enum speed_enum i2c_amd_get_bus_speed(struct platform_device *pdev)
+{
+ u32 acpi_speed;
+ int i;
+ static const u32 supported_speeds[] = {
+ 0, 100000, 400000, 1000000, 1400000, 3400000
+ };
+
+ acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
+ /* round down to the lowest standard speed */
+ for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) {
+ if (acpi_speed < supported_speeds[i])
+ break;
+ }
+ acpi_speed = supported_speeds[i - 1];
+
+ switch (acpi_speed) {
+ case 100000:
+ return speed100k;
+ case 400000:
+ return speed400k;
+ case 1000000:
+ return speed1000k;
+ case 1400000:
+ return speed1400k;
+ case 3400000:
+ return speed3400k;
+ default:
+ return speed400k;
+ }
+}
+
+static const struct i2c_adapter_quirks amd_i2c_dev_quirks = {
+ .max_read_len = AMD_MP2_I2C_MAX_RW_LENGTH,
+ .max_write_len = AMD_MP2_I2C_MAX_RW_LENGTH,
+};
+
+static int i2c_amd_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct amd_i2c_dev *i2c_dev;
+ acpi_handle handle = ACPI_HANDLE(&pdev->dev);
+ struct acpi_device *adev;
+ struct amd_mp2_dev *mp2_dev;
+ const char *uid;
+
+ if (acpi_bus_get_device(handle, &adev))
+ return -ENODEV;
+
+ /* The ACPI namespace doesn't contain information about which MP2 PCI
+ * device an AMDI0011 ACPI device is related to, so assume that there's
+ * only one MP2 PCI device per system.
+ */
+ mp2_dev = amd_mp2_find_device();
+ if (!mp2_dev || !mp2_dev->probed)
+ /* The MP2 PCI device should get probed later */
+ return -EPROBE_DEFER;
+
+ i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
+ if (!i2c_dev)
+ return -ENOMEM;
+
+ i2c_dev->common.mp2_dev = mp2_dev;
+ i2c_dev->pdev = pdev;
+ platform_set_drvdata(pdev, i2c_dev);
+
+ i2c_dev->common.cmd_completion = &i2c_amd_cmd_completion;
+#ifdef CONFIG_PM
+ i2c_dev->common.suspend = &i2c_amd_suspend;
+ i2c_dev->common.resume = &i2c_amd_resume;
+#endif
+
+ uid = adev->pnp.unique_id;
+ if (!uid) {
+ dev_err(&pdev->dev, "missing UID/bus id!\n");
+ return -EINVAL;
+ } else if (strcmp(uid, "0") == 0) {
+ i2c_dev->common.bus_id = 0;
+ } else if (strcmp(uid, "1") == 0) {
+ i2c_dev->common.bus_id = 1;
+ } else {
+ dev_err(&pdev->dev, "incorrect UID/bus id \"%s\"!\n", uid);
+ return -EINVAL;
+ }
+ dev_dbg(&pdev->dev, "bus id is %u\n", i2c_dev->common.bus_id);
+
+ /* Register the adapter */
+ amd_mp2_pm_runtime_get(mp2_dev);
+
+ i2c_dev->common.reqcmd = i2c_none;
+ if (amd_mp2_register_cb(&i2c_dev->common))
+ return -EINVAL;
+ device_link_add(&i2c_dev->pdev->dev, &mp2_dev->pci_dev->dev,
+ DL_FLAG_AUTOREMOVE);
+
+ i2c_dev->common.i2c_speed = i2c_amd_get_bus_speed(pdev);
+
+ /* Setup i2c adapter description */
+ i2c_dev->adap.owner = THIS_MODULE;
+ i2c_dev->adap.algo = &i2c_amd_algorithm;
+ i2c_dev->adap.quirks = &amd_i2c_dev_quirks;
+ i2c_dev->adap.dev.parent = &pdev->dev;
+ i2c_dev->adap.algo_data = i2c_dev;
+ i2c_dev->adap.timeout = AMD_I2C_TIMEOUT;
+ ACPI_COMPANION_SET(&i2c_dev->adap.dev, ACPI_COMPANION(&pdev->dev));
+ i2c_dev->adap.dev.of_node = pdev->dev.of_node;
+ snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
+ "AMD MP2 i2c bus %u", i2c_dev->common.bus_id);
+ i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
+
+ init_completion(&i2c_dev->cmd_complete);
+
+ /* Enable the bus */
+ if (i2c_amd_enable_set(i2c_dev, true))
+ dev_err(&pdev->dev, "initial bus enable failed\n");
+
+ /* Attach to the i2c layer */
+ ret = i2c_add_adapter(&i2c_dev->adap);
+
+ amd_mp2_pm_runtime_put(mp2_dev);
+
+ if (ret < 0)
+ dev_err(&pdev->dev, "i2c add adapter failed = %d\n", ret);
+
+ return ret;
+}
+
+static int i2c_amd_remove(struct platform_device *pdev)
+{
+ struct amd_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+ struct amd_i2c_common *i2c_common = &i2c_dev->common;
+
+ i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
+
+ i2c_amd_enable_set(i2c_dev, false);
+ amd_mp2_unregister_cb(i2c_common);
+ i2c_common->mp2_dev = NULL;
+
+ i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
+
+ i2c_del_adapter(&i2c_dev->adap);
+ return 0;
+}
+
+static const struct acpi_device_id i2c_amd_acpi_match[] = {
+ { "AMDI0011" },
+ { },
+};
+MODULE_DEVICE_TABLE(acpi, i2c_amd_acpi_match);
+
+static struct platform_driver i2c_amd_plat_driver = {
+ .probe = i2c_amd_probe,
+ .remove = i2c_amd_remove,
+ .driver = {
+ .name = "i2c_amd_mp2",
+ .acpi_match_table = ACPI_PTR(i2c_amd_acpi_match),
+ },
+};
+module_platform_driver(i2c_amd_plat_driver);
+
+MODULE_DESCRIPTION("AMD(R) MP2 I2C Platform Driver");
+MODULE_AUTHOR("Nehal Shah <nehal-bakulchandra.shah at amd.com>");
+MODULE_AUTHOR("Elie Morisse <syniurge at gmail.com>");
+MODULE_LICENSE("Dual BSD/GPL");
diff --git a/drivers/i2c/busses/i2c-amd-mp2.h b/drivers/i2c/busses/i2c-amd-mp2.h
new file mode 100644
index 000000000000..058362edebaa
--- /dev/null
+++ b/drivers/i2c/busses/i2c-amd-mp2.h
@@ -0,0 +1,219 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * AMD MP2 I2C adapter driver
+ *
+ * Authors: Shyam Sundar S K <Shyam-sundar.S-k at amd.com>
+ * Elie Morisse <syniurge at gmail.com>
+ */
+
+#ifndef I2C_AMD_PCI_MP2_H
+#define I2C_AMD_PCI_MP2_H
+
+#include <linux/i2c.h>
+#include <linux/pci.h>
+#include <linux/pm_runtime.h>
+
+#define PCI_DEVICE_ID_AMD_MP2 0x15E6
+
+struct amd_i2c_common;
+struct amd_mp2_dev;
+
+enum {
+ /* MP2 C2P Message Registers */
+ AMD_C2P_MSG0 = 0x10500, /* MP2 Message for I2C0 */
+ AMD_C2P_MSG1 = 0x10504, /* MP2 Message for I2C1 */
+ AMD_C2P_MSG2 = 0x10508, /* DRAM Address Lo / Data 0 */
+ AMD_C2P_MSG3 = 0x1050c, /* DRAM Address HI / Data 1 */
+ AMD_C2P_MSG4 = 0x10510, /* Data 2 */
+ AMD_C2P_MSG5 = 0x10514, /* Data 3 */
+ AMD_C2P_MSG6 = 0x10518, /* Data 4 */
+ AMD_C2P_MSG7 = 0x1051c, /* Data 5 */
+ AMD_C2P_MSG8 = 0x10520, /* Data 6 */
+ AMD_C2P_MSG9 = 0x10524, /* Data 7 */
+
+ /* MP2 P2C Message Registers */
+ AMD_P2C_MSG0 = 0x10680, /* Do not use */
+ AMD_P2C_MSG1 = 0x10684, /* I2C0 interrupt register */
+ AMD_P2C_MSG2 = 0x10688, /* I2C1 interrupt register */
+ AMD_P2C_MSG3 = 0x1068C, /* MP2 debug info */
+ AMD_P2C_MSG_INTEN = 0x10690, /* MP2 interrupt gen register */
+ AMD_P2C_MSG_INTSTS = 0x10694, /* Interrupt status */
+};
+
+/* Command register data structures */
+
+#define i2c_none (-1)
+enum i2c_cmd {
+ i2c_read = 0,
+ i2c_write,
+ i2c_enable,
+ i2c_disable,
+ number_of_sensor_discovered,
+ is_mp2_active,
+ invalid_cmd = 0xF,
+};
+
+enum speed_enum {
+ speed100k = 0,
+ speed400k = 1,
+ speed1000k = 2,
+ speed1400k = 3,
+ speed3400k = 4
+};
+
+enum mem_type {
+ use_dram = 0,
+ use_c2pmsg = 1,
+};
+
+/**
+ * union i2c_cmd_base : bit access of C2P commands
+ * @i2c_cmd: bit 0..3 i2c R/W command
+ * @bus_id: bit 4..7 i2c bus index
+ * @slave_addr: bit 8..15 slave address
+ * @length: bit 16..27 read/write length
+ * @i2c_speed: bit 28..30 bus speed
+ * @mem_type: bit 31 0-DRAM; 1-C2P msg o/p
+ */
+union i2c_cmd_base {
+ u32 ul;
+ struct {
+ enum i2c_cmd i2c_cmd : 4;
+ u8 bus_id : 4;
+ u32 slave_addr : 8;
+ u32 length : 12;
+ enum speed_enum i2c_speed : 3;
+ enum mem_type mem_type : 1;
+ } s;
+};
+
+enum response_type {
+ invalid_response = 0,
+ command_success = 1,
+ command_failed = 2,
+};
+
+enum status_type {
+ i2c_readcomplete_event = 0,
+ i2c_readfail_event = 1,
+ i2c_writecomplete_event = 2,
+ i2c_writefail_event = 3,
+ i2c_busenable_complete = 4,
+ i2c_busenable_failed = 5,
+ i2c_busdisable_complete = 6,
+ i2c_busdisable_failed = 7,
+ invalid_data_length = 8,
+ invalid_slave_address = 9,
+ invalid_i2cbus_id = 10,
+ invalid_dram_addr = 11,
+ invalid_command = 12,
+ mp2_active = 13,
+ numberof_sensors_discovered_resp = 14,
+ i2c_bus_notinitialized
+};
+
+/**
+ * union i2c_event : bit access of P2C events
+ * @response: bit 0..1 i2c response type
+ * @status: bit 2..6 status_type
+ * @mem_type: bit 7 0-DRAM; 1-C2P msg o/p
+ * @bus_id: bit 8..11 i2c bus id
+ * @length: bit 12..23 message length
+ * @slave_addr: bit 24-31 slave address
+ */
+union i2c_event {
+ u32 ul;
+ struct {
+ enum response_type response : 2;
+ enum status_type status : 5;
+ enum mem_type mem_type : 1;
+ u8 bus_id : 4;
+ u32 length : 12;
+ u32 slave_addr : 8;
+ } r;
+};
+
+/**
+ * struct amd_i2c_common - per bus/i2c adapter context, shared
+ * between the pci and the platform driver
+ * @eventval: MP2 event value set by the IRQ handler
+ * @mp2_dev: MP2 pci device this adapter is part of
+ * @msg: i2c message
+ * @cmd_completion: function called by the IRQ handler to signal
+ * the platform driver
+ * @reqcmd: requested i2c command type
+ * @cmd_success: set to true if the MP2 responded to a command with
+ * the expected status and response type
+ * @bus_id: bus index
+ * @i2c_speed: i2c bus speed determined by the slowest slave
+ * @dma_buf: if msg length > 32, holds the DMA buffer virtual address
+ * @dma_addr: if msg length > 32, holds the DMA buffer address
+ */
+struct amd_i2c_common {
+ union i2c_event eventval;
+ struct amd_mp2_dev *mp2_dev;
+ struct i2c_msg *msg;
+ void (*cmd_completion)(struct amd_i2c_common *i2c_common);
+ enum i2c_cmd reqcmd;
+ u8 cmd_success;
+ u8 bus_id;
+ enum speed_enum i2c_speed;
+ u8 *dma_buf;
+ dma_addr_t dma_addr;
+#ifdef CONFIG_PM
+ int (*suspend)(struct amd_i2c_common *i2c_common);
+ int (*resume)(struct amd_i2c_common *i2c_common);
+#endif /* CONFIG_PM */
+};
+
+/**
+ * struct amd_mp2_dev - per PCI device context
+ * @pci_dev: PCI driver node
+ * @busses: MP2 devices may have up to two busses,
+ * each bus corresponding to an i2c adapter
+ * @mmio: iommapped registers
+ * @c2p_lock: controls access to the C2P mailbox shared between
+ * the two adapters
+ * @c2p_lock_busid: id of the adapter which locked c2p_lock
+ */
+struct amd_mp2_dev {
+ struct pci_dev *pci_dev;
+ struct amd_i2c_common *busses[2];
+ void __iomem *mmio;
+ struct mutex c2p_lock;
+ u8 c2p_lock_busid;
+ unsigned int probed;
+};
+
+#define ndev_pdev(ndev) ((ndev)->pci_dev)
+#define ndev_name(ndev) pci_name(ndev_pdev(ndev))
+#define ndev_dev(ndev) (&ndev_pdev(ndev)->dev)
+#define work_amd_i2c_common(__work) \
+ container_of(__work, struct amd_i2c_common, work.work)
+
+/* PCIe communication driver */
+
+int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd);
+int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable);
+
+void amd_mp2_process_event(struct amd_i2c_common *i2c_common);
+
+void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common);
+
+int amd_mp2_register_cb(struct amd_i2c_common *i2c_common);
+int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common);
+
+struct amd_mp2_dev *amd_mp2_find_device(void);
+
+static inline void amd_mp2_pm_runtime_get(struct amd_mp2_dev *mp2_dev)
+{
+ pm_runtime_get_sync(&mp2_dev->pci_dev->dev);
+}
+
+static inline void amd_mp2_pm_runtime_put(struct amd_mp2_dev *mp2_dev)
+{
+ pm_runtime_mark_last_busy(&mp2_dev->pci_dev->dev);
+ pm_runtime_put_autosuspend(&mp2_dev->pci_dev->dev);
+}
+
+#endif
--
2.17.1
More information about the kernel-team
mailing list