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 Changes since v15 by Elie M.: -> changes requested by Wolfram Sang in his v15 review Changes since v16 by Elie M.: -> ensure that writeq gets defined -> fix the device name in Documentation/ to match the entry at pci-ids (https://pci-ids.ucw.cz/read/PC/1022/15e6) -> remove the unused DRIVER_xxx defines (forgot to remove them in v16) 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@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 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 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..c97478e65102 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 5f0cb6915969..2e98a6618ce5 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -33,6 +33,7 @@ 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@xxxxxxx> + * Elie Morisse <syniurge@xxxxxxxxx> + */ + +#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@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..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@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 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_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.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@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..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@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; + 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
