Re: [PATCH v15] i2c: Add drivers for the AMD PCIe MP2 I2C controller
From: Elie Morisse
Date: Fri Dec 28 2018 - 14:18:50 EST
Hi,
Nehal isn't responding, while the end of the merge window is closing
in. I addressed his last requests, will this get merged?
Elie
Le mer. 26 dÃc. 2018 Ã 20:23, Elie Morisse <syniurge@xxxxxxxxx> a Ãcrit :
>
> 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@xxxxxxxxx>
> ---
> Changes since v1 (https://www.spinics.net/lists/linux-i2c/msg34650.html):
> -> Add fix for IOMMU
> -> Add dependency of ACPI
> -> Add locks to avoid the crash
>
> Changes since v2 (https://patchwork.ozlabs.org/patch/961270/):
>
> -> fix for review comments
> -> fix for more than 32 bytes write issue
>
> Changes since v3 (https://patchwork.kernel.org/patch/10597369/) by Elie M.:
>
> -> support more than one bus/adapter
> -> support more than one slave per bus
> -> use the bus speed specified by the slaves declared in the DSDT instead of
> assuming speed == 400kbits/s
> -> instead of kzalloc'ing a buffer for every less than 32 bytes reads, simply
> use i2c_msg.buf
> -> fix buffer overreads/overflows when (<=32 bytes) message lengths aren't a
> multiple of 4 by using memcpy_fromio and memcpy_toio
> -> use streaming DMA mappings instead of allocating a coherent DMA buffer for
> every >32 bytes read/write
> -> properly check for timeouts during i2c_amd_xfer and increase it from 50
> jiffies to 250 msecs (which is more in line with other drivers)
> -> complete amd_i2c_dev.msg even if the device doesn't return a xxx_success
> event, instead of stalling i2c_amd_xfer
> -> removed the spinlock and mdelay during i2c_amd_pci_configure, I didn't see
> the point since it's already waiting for a i2c_busenable_complete event
> -> add an adapter-specific mutex lock for i2c_amd_xfer, since we don't want
> parallel calls writing to AMD_C2P_MSG0 (or AMD_C2P_MSG1)
> -> add a global mutex lock for registers AMD_C2P_MSG2 to AMD_C2P_MSG9, which
> are shared across the two busses/adapters
> -> add MODULE_DEVICE_TABLE to automatically load i2c-amd-platdrv if the DSDT
> enumerates devices with the "AMDI0011" HID
> -> set maximum length of reads/writes to 4095 (event's length field is 12 bits)
> -> basic PM support
> -> style corrections to match the kernel code style, and tried to reduce code
> duplication whenever possible
>
> Changes since v4 by Elie M.:
>
> -> fix missing typecast warning
> -> removed the duplicated entry in Kconfig
>
> Changes since v5 by Elie M.:
>
> -> move DMA mapping from the platform driver to the PCI driver
> -> attempt to find the platform device's PCI parent through the _DEP ACPI method
> (if not found take the first MP2 device registred in the i2c-amd-pci-mp2
> driver, like before)
> -> do not assume anymore that the PCI device is owned by the i2c-amd-pci-mp2
> driver
> -> address other review comments by Bjorn Helgaas (meant for v3)
>
> Changes since v6 by Elie M.:
>
> -> remove unnecessary memcpy from the DMA buffer during i2c_amd_read_completion
>
> Changes since v7 by Elie M.:
>
> -> merge the two modules into one named i2c-amd-mp2, delete now useless exports
> -> unlock the C2P mutex if i2c_amd_xfer_msg timeouts, to prevent stalling the
> MP2 controller if a slave doesn't respond to a read or write request
> -> unmap the DMA buffer before read/write_complete
> -> fix bus_disable commands handling (no more errors during module exit)
> -> prefer managed versions of pci_ and dev_ functions whenever possible
> -> increase adapter retries from 0 to 3
> -> reduce code duplication in debugfs functions
> -> address other review points by Bjorn Helgaas (except regarding the _DEP
> hint)
>
> Changes since v8 by Elie M.:
>
> -> remove mostly redundant amd_i2c_rw_config, refer to i2c_msg whenever
> possible
> -> use i2c_get_dma_safe_msg_buf and i2c_put_dma_safe_msg_buf
> -> defer probe() by the platform driver if no MP2 device has been probed
> yet by the PCI driver (which should address Bjorn Helgaas' concern while
> preserving the platform driver)
> -> if the interrupt following a command doesn't get handled after 250ms,
> zero AMD_P2C_MSG_INTEN to prevent the MP2 from stalling for a few more
> seconds
> -> include AMD_P2C_MSG3 and fix typo in debugfs output
> -> cosmetic fixes, code reduction, and better comments
> -> add Nehal Shah and Shyam Sundar S K from AMD to the list of maintainers
>
> Changes since v9 by Elie M.:
>
> -> remove the xfer_lock mutex which was redundant with i2c_adapter.bus_lock
> -> platform device remove() fixes (protection against the very unlikely
> case that both the PCI and platform devices get detached manually and
> simultaneously)
> -> fix manually unbinding the PCI device and then rebinding, there was an
> interrupt that wouldn't get serviced and thus the line got disabled
> -> look for the MP2 device corresponding to an AMDI0011 ACPI device in
> every device enumerated by _DEP, not just the first one
> -> set i2c_adapter.nr to pdev->id and call i2c_add_numbered_adapter()
> -> add Documentation/i2c/busses/ entry
> -> minor enhancements
>
> Changes since v10 by Elie M.:
>
> -> runtime PM support
> -> synchronisation fixes for <=32 bytes reads/writes through C2P registers,
> no more timeouts or "irq: nobody cared" errors on Lenovo Ideapad 530s
> -> remove the isr spinlock, not needed since isr aren't re-entrant
> -> remove the delayed_work field, make the isr complete .cmd_complete
> directly
> -> xfer now returns -EIO if the MP2 response isn't the expected one
> -> check that the adapter still exists at the beginning of xfer
> -> less code duplication in amd_mp2_read/write
> -> better names (bus_xnable => bus_enable_set, _msg => _cmd) and other
> minor enhancements
>
> Changes since v11 by Elie M.:
>
> -> remove the ACPI _DEP hint, Nehal from AMD said that there's no plan to
> have more than one MP2 device per system and this wasn't _DEP's purpose
> -> use device links between the two drivers to simplify the .remove logic
> -> do not hardcode the i2c adapter timeout
> -> code reduction and comment fixes
>
> Changes since v12 by Elie M.:
>
> -> fix the two warnings by the kbuild test bot
>
> Changes since v13 by Elie M., requested by Nehal Shah from AMD:
>
> -> split the i2c-amd-mp2 module back into two, i2c-amd-mp2-pci and
> i2c-amd-mp2-plat
> -> move DMA mapping back into the platform driver
>
> Changes since v14 by Elie M.:
>
> -> fix build failure if CONFIG_PM isn't defined
>
> Documentation/i2c/busses/i2c-amd-mp2 | 24 +
> MAINTAINERS | 8 +
> drivers/i2c/busses/Kconfig | 21 +
> drivers/i2c/busses/Makefile | 2 +
> drivers/i2c/busses/i2c-amd-mp2-pci.c | 650 ++++++++++++++++++++++++++
> drivers/i2c/busses/i2c-amd-mp2-plat.c | 392 ++++++++++++++++
> drivers/i2c/busses/i2c-amd-mp2.h | 223 +++++++++
> 7 files changed, 1320 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..4b3d4b804413
> --- /dev/null
> +++ b/Documentation/i2c/busses/i2c-amd-mp2
> @@ -0,0 +1,24 @@
> +Kernel driver i2c-amd-mp2
> +
> +Supported adapters:
> + * AMD MP2 PCIe interface
> +
> +Datasheet: not publicly available.
> +
> +Authors:
> + Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>
> + Nehal Shah <nehal-bakulchandra.shah@xxxxxxx>
> + Elie Morisse <syniurge@xxxxxxxxx>
> +
> +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 Non-VGA unclassified device: 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 d27401df091f..76f8b3c40132 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -808,6 +808,14 @@ 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@xxxxxxxxx>
> +M: Nehal Shah <nehal-bakulchandra.shah@xxxxxxx>
> +M: Shyam Sundar S K <shyam-sundar.s-k@xxxxxxx>
> +L: linux-i2c@xxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/i2c/busses/i2c-amd-mp2*
> +
> AMD POWERPLAY
> M: Rex Zhu <rex.zhu@xxxxxxx>
> M: Evan Quan <evan.quan@xxxxxxx>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index f2c681971201..ef7617dd5d01 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -77,6 +77,27 @@ 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_PCI
> + tristate "AMD MP2 PCIe"
> + depends on PCI
> + 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 a module. If so, the module
> + will be called i2c-amd-mp2-pci.
> +
> +config I2C_AMD_MP2_PLATFORM
> + tristate "AMD MP2 Platform"
> + select I2C_AMD_MP2_PCI
> + depends on ACPI
> + help
> + If you say yes to this option, support will be included for the AMD
> + MP2 I2C adapter.
> +
> + This driver can also be built as a module. If so, the module
> + will be called 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 5f0cb6915969..4fa829dccf68 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -33,6 +33,8 @@ obj-$(CONFIG_I2C_POWERMAC) += i2c-powermac.o
>
> # Embedded system I2C/SMBus host controller drivers
> obj-$(CONFIG_I2C_ALTERA) += i2c-altera.o
> +obj-$(CONFIG_I2C_AMD_MP2_PCI) += i2c-amd-mp2-pci.o
> +obj-$(CONFIG_I2C_AMD_MP2_PLATFORM) += 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..3abbb673acd3
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c
> @@ -0,0 +1,650 @@
> +// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
> +/*
> + * AMD MP2 PCIe communication driver
> + *
> + * Authors: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>
> + * Elie Morisse <syniurge@xxxxxxxxx>
> + */
> +
> +#include <linux/debugfs.h>
> +#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"
> +
> +#define DRIVER_NAME "i2c_amd_mp2"
> +#define DRIVER_DESC "AMD(R) PCI-E MP2 I2C Controller Driver"
> +#define DRIVER_VER "1.0"
> +
> +static inline void write64(u64 val, void __iomem *mmio)
> +{
> + writel(val, mmio);
> + writel(val >> 32, mmio + sizeof(u32));
> +}
> +
> +static inline u64 read64(void __iomem *mmio)
> +{
> + u64 low, high;
> +
> + low = readl(mmio);
> + high = readl(mmio + sizeof(u32));
> + return low | (high << 32);
> +}
> +
> +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;
> +}
> +
> +static 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;
> + write64((u64)i2c_common->dma_addr,
> + privdata->mmio + AMD_C2P_MSG2);
> + }
> +
> + return amd_mp2_cmd(i2c_common, i2c_cmd_base);
> +}
> +
> +int amd_mp2_read(struct amd_i2c_common *i2c_common)
> +{
> + struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
> +
> + dev_dbg(ndev_dev(privdata), "%s addr: %x id: %d\n", __func__,
> + i2c_common->msg->addr, i2c_common->bus_id);
> +
> + return amd_mp2_rw(i2c_common, i2c_read);
> +}
> +EXPORT_SYMBOL_GPL(amd_mp2_read);
> +
> +int amd_mp2_write(struct amd_i2c_common *i2c_common)
> +{
> + struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
> +
> + dev_dbg(ndev_dev(privdata), "%s addr: %x id: %d\n", __func__,
> + i2c_common->msg->addr, i2c_common->bus_id);
> +
> + return amd_mp2_rw(i2c_common, i2c_write);
> +}
> +EXPORT_SYMBOL_GPL(amd_mp2_write);
> +
> +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), "i2c command failed!\n");
> + else
> + 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,
> + i2c_common->msg->len);
> + } else if (sts == i2c_readfail_event) {
> + dev_err(ndev_dev(privdata), "i2c read failed!\n");
> + } else {
> + 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), "i2c write failed!\n");
> + else
> + dev_err(ndev_dev(privdata),
> + "invalid i2c status after write (%d)!\n", sts);
> + break;
> + case i2c_enable:
> + if (sts == i2c_busenable_failed)
> + dev_err(ndev_dev(privdata), "i2c bus enable failed!\n");
> + else if (sts != i2c_busenable_complete)
> + dev_err(ndev_dev(privdata),
> + "invalid i2c status after bus enable (%d)!\n",
> + sts);
> + else
> + i2c_common->cmd_success = true;
> + break;
> + case i2c_disable:
> + if (sts == i2c_busdisable_failed)
> + dev_err(ndev_dev(privdata), "i2c bus disable failed!\n");
> + else if (sts != i2c_busdisable_complete)
> + dev_err(ndev_dev(privdata),
> + "invalid i2c status after bus disable (%d)!\n",
> + sts);
> + else
> + i2c_common->cmd_success = true;
> + 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 (unlikely(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);
> +
> +#ifdef CONFIG_DEBUG_FS
> +static const struct file_operations amd_mp2_debugfs_info;
> +static struct dentry *debugfs_root_dir;
> +
> +static ssize_t amd_mp2_debugfs_read(struct file *filp, char __user *ubuf,
> + size_t count, loff_t *offp)
> +{
> + struct amd_mp2_dev *privdata = filp->private_data;
> + size_t buf_size = min_t(size_t, count, 0x800);
> + u8 *buf;
> + ssize_t ret, off = 0;
> + u32 v32;
> + int i;
> +
> + buf = kmalloc(buf_size, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + off += scnprintf(buf + off, buf_size - off,
> + "MP2 Device Information:\n"
> + "========================\n"
> + "\tMP2 C2P Message Register Dump:\n\n");
> +
> + for (i = 0; i < 10; i++) {
> + v32 = readl(privdata->mmio + AMD_C2P_MSG0 + i * 4);
> + off += scnprintf(buf + off, buf_size - off,
> + "AMD_C2P_MSG%d -\t\t\t%#06x\n", i, v32);
> + }
> +
> + off += scnprintf(buf + off, buf_size - off,
> + "\n\tMP2 P2C Message Register Dump:\n\n");
> +
> + for (i = 0; i < 3; i++) {
> + v32 = readl(privdata->mmio + AMD_P2C_MSG1 + i * 4);
> + off += scnprintf(buf + off, buf_size - off,
> + "AMD_P2C_MSG%d -\t\t\t%#06x\n", i + 1, v32);
> + }
> +
> + v32 = readl(privdata->mmio + AMD_P2C_MSG_INTEN);
> + off += scnprintf(buf + off, buf_size - off,
> + "AMD_P2C_MSG_INTEN -\t\t%#06x\n", v32);
> +
> + v32 = readl(privdata->mmio + AMD_P2C_MSG_INTSTS);
> + off += scnprintf(buf + off, buf_size - off,
> + "AMD_P2C_MSG_INTSTS -\t\t%#06x\n", v32);
> +
> + ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
> + kfree(buf);
> + return ret;
> +}
> +
> +static const struct file_operations amd_mp2_debugfs_info = {
> + .owner = THIS_MODULE,
> + .open = simple_open,
> + .read = amd_mp2_debugfs_read,
> +};
> +
> +static void amd_mp2_init_debugfs(struct amd_mp2_dev *privdata)
> +{
> + if (!debugfs_root_dir)
> + return;
> +
> + privdata->debugfs_dir = debugfs_create_dir(ndev_name(privdata),
> + debugfs_root_dir);
> + if (!privdata->debugfs_dir) {
> + privdata->debugfs_info = NULL;
> + } else {
> + privdata->debugfs_info = debugfs_create_file
> + ("info", 0400, privdata->debugfs_dir,
> + privdata, &amd_mp2_debugfs_info);
> + }
> +}
> +#endif /* CONFIG_DEBUG_FS */
> +
> +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;
> + static bool first_probe = true;
> +
> + if (first_probe) {
> + pr_info("%s: %s Version: %s\n", DRIVER_NAME,
> + DRIVER_DESC, DRIVER_VER);
> + first_probe = false;
> + }
> +
> + dev_info(&pci_dev->dev, "MP2 device found [%04x:%04x] (rev %x)\n",
> + pci_dev->vendor, pci_dev->device, pci_dev->revision);
> +
> + 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);
> +
> + amd_mp2_init_debugfs(privdata);
> + dev_info(&pci_dev->dev, "MP2 device registered.\n");
> + return 0;
> +}
> +
> +static bool amd_mp2_pci_is_probed(struct pci_dev *pci_dev)
> +{
> + struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
> +
> + if (!privdata)
> + return false;
> + return privdata->pci_dev != NULL;
> +}
> +
> +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);
> +
> +#ifdef CONFIG_DEBUG_FS
> + debugfs_remove_recursive(privdata->debugfs_dir);
> +#endif /* CONFIG_DEBUG_FS */
> +
> + 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 = DRIVER_NAME,
> + .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
> +};
> +
> +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);
> + if (!amd_mp2_pci_is_probed(pci_dev))
> + return NULL;
> + return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
> +}
> +EXPORT_SYMBOL_GPL(amd_mp2_find_device);
> +
> +static int __init amd_mp2_drv_init(void)
> +{
> +#ifdef CONFIG_DEBUG_FS
> + debugfs_root_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
> +#endif /* CONFIG_DEBUG_FS */
> +
> + return pci_register_driver(&amd_mp2_pci_driver);
> +}
> +module_init(amd_mp2_drv_init);
> +
> +static void __exit amd_mp2_drv_exit(void)
> +{
> + pci_unregister_driver(&amd_mp2_pci_driver);
> +
> +#ifdef CONFIG_DEBUG_FS
> + debugfs_remove_recursive(debugfs_root_dir);
> +#endif /* CONFIG_DEBUG_FS */
> +}
> +module_exit(amd_mp2_drv_exit);
> +
> +MODULE_DESCRIPTION(DRIVER_DESC);
> +MODULE_VERSION(DRIVER_VER);
> +MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>");
> +MODULE_AUTHOR("Elie Morisse <syniurge@xxxxxxxxx>");
> +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..06cf2b6658e5
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-amd-mp2-plat.c
> @@ -0,0 +1,392 @@
> +// 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@xxxxxxx>
> + * Elie Morisse <syniurge@xxxxxxxxx>
> + */
> +
> +#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_put_dma_safe_msg_buf(i2c_common->dma_buf, i2c_common->msg, true);
> +}
> +
> +static const char *i2c_amd_cmd_name(enum i2c_cmd cmd)
> +{
> + switch (cmd) {
> + case i2c_read:
> + return "i2c read";
> + case i2c_write:
> + return "i2c write";
> + case i2c_enable:
> + return "bus enable";
> + case i2c_disable:
> + return "bus disable";
> + case number_of_sensor_discovered:
> + return "'number of sensors discovered' cmd";
> + case is_mp2_active:
> + return "'is mp2 active' cmd";
> + default:
> + return "invalid cmd";
> + }
> +}
> +
> +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 (unlikely(timeout == 0)) {
> + dev_err(&i2c_dev->pdev->dev, "%s timed out\n",
> + i2c_amd_cmd_name(i2c_common->reqcmd));
> + amd_mp2_rw_timeout(i2c_common);
> + }
> +
> + if ((i2c_common->reqcmd == i2c_read ||
> + i2c_common->reqcmd == i2c_write) &&
> + i2c_common->msg->len > 32)
> + i2c_amd_dma_unmap(i2c_common);
> +
> + if (unlikely(timeout == 0))
> + 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_read(i2c_common);
> + else
> + amd_mp2_write(i2c_common);
> +
> + 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;
> +}
> +
> +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)
> + /* The MP2 PCI device might 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_CONSUMER);
> +
> + 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.nr = pdev->id;
> + 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_numbered_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_VERSION("1.0");
> +MODULE_AUTHOR("Nehal Shah <nehal-bakulchandra.shah@xxxxxxx>");
> +MODULE_AUTHOR("Elie Morisse <syniurge@xxxxxxxxx>");
> +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..aff9a4e4369e
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-amd-mp2.h
> @@ -0,0 +1,223 @@
> +/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
> +/*
> + * AMD MP2 I2C adapter driver
> + *
> + * Authors: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx>
> + * Elie Morisse <syniurge@xxxxxxxxx>
> + */
> +
> +#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;
> +#ifdef CONFIG_DEBUG_FS
> + struct dentry *debugfs_dir;
> + struct dentry *debugfs_info;
> +#endif /* CONFIG_DEBUG_FS */
> +};
> +
> +#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_read(struct amd_i2c_common *i2c_common);
> +int amd_mp2_write(struct amd_i2c_common *i2c_common);
> +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
>