diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/i2c/busses/i2c-amd-mp2-plat.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-amd-mp2-plat.c')
-rw-r--r-- | drivers/i2c/busses/i2c-amd-mp2-plat.c | 361 |
1 files changed, 361 insertions, 0 deletions
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 000000000..423fe0c8a --- /dev/null +++ b/drivers/i2c/busses/i2c-amd-mp2-plat.c @@ -0,0 +1,361 @@ +// 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@amd.com> + * Elie Morisse <syniurge@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_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, "readdata:%*ph\n", 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 = 0; + + /* 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 const u32 supported_speeds[] = { + I2C_MAX_HIGH_SPEED_MODE_FREQ, + I2C_MAX_TURBO_MODE_FREQ, + I2C_MAX_FAST_MODE_PLUS_FREQ, + I2C_MAX_FAST_MODE_FREQ, + I2C_MAX_STANDARD_MODE_FREQ, +}; + +static enum speed_enum i2c_amd_get_bus_speed(struct platform_device *pdev) +{ + u32 acpi_speed; + int i; + + acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev); + /* round down to the lowest standard speed */ + for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) { + if (acpi_speed >= supported_speeds[i]) + break; + } + acpi_speed = i < ARRAY_SIZE(supported_speeds) ? supported_speeds[i] : 0; + + switch (acpi_speed) { + case I2C_MAX_STANDARD_MODE_FREQ: + return speed100k; + case I2C_MAX_FAST_MODE_FREQ: + return speed400k; + case I2C_MAX_FAST_MODE_PLUS_FREQ: + return speed1000k; + case I2C_MAX_TURBO_MODE_FREQ: + return speed1400k; + case I2C_MAX_HIGH_SPEED_MODE_FREQ: + 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) +{ + struct device *dev = &pdev->dev; + int ret; + struct amd_i2c_dev *i2c_dev; + struct amd_mp2_dev *mp2_dev; + u64 uid; + + ret = acpi_dev_uid_to_integer(ACPI_COMPANION(dev), &uid); + if (ret) + return dev_err_probe(dev, ret, "missing UID/bus id!\n"); + if (uid >= 2) + return dev_err_probe(dev, -EINVAL, "incorrect UID/bus id \"%llu\"!\n", uid); + dev_dbg(dev, "bus id is %llu\n", uid); + + /* 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.bus_id = uid; + 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 + + /* 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@amd.com>"); +MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>"); +MODULE_LICENSE("Dual BSD/GPL"); |