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Diffstat (limited to 'drivers/i2c/busses/i2c-amd-mp2-plat.c')
-rw-r--r--drivers/i2c/busses/i2c-amd-mp2-plat.c361
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");