summaryrefslogtreecommitdiffstats
path: root/drivers/i2c/busses/i2c-amd-mp2-pci.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/i2c/busses/i2c-amd-mp2-pci.c477
1 files changed, 477 insertions, 0 deletions
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 000000000..cd3fd5ee5
--- /dev/null
+++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c
@@ -0,0 +1,477 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * AMD MP2 PCIe communication driver
+ *
+ * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ * Elie Morisse <syniurge@gmail.com>
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include "i2c-amd-mp2.h"
+
+#include <linux/io-64-nonatomic-lo-hi.h>
+
+static void amd_mp2_c2p_mutex_lock(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ /* there is only one data mailbox for two i2c adapters */
+ mutex_lock(&privdata->c2p_lock);
+ privdata->c2p_lock_busid = i2c_common->bus_id;
+}
+
+static void amd_mp2_c2p_mutex_unlock(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ if (unlikely(privdata->c2p_lock_busid != i2c_common->bus_id)) {
+ dev_warn(ndev_dev(privdata),
+ "bus %d attempting to unlock C2P locked by bus %d\n",
+ i2c_common->bus_id, privdata->c2p_lock_busid);
+ return;
+ }
+
+ mutex_unlock(&privdata->c2p_lock);
+}
+
+static int amd_mp2_cmd(struct amd_i2c_common *i2c_common,
+ union i2c_cmd_base i2c_cmd_base)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ void __iomem *reg;
+
+ i2c_common->reqcmd = i2c_cmd_base.s.i2c_cmd;
+
+ reg = privdata->mmio + ((i2c_cmd_base.s.bus_id == 1) ?
+ AMD_C2P_MSG1 : AMD_C2P_MSG0);
+ writel(i2c_cmd_base.ul, reg);
+
+ return 0;
+}
+
+int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ union i2c_cmd_base i2c_cmd_base;
+
+ dev_dbg(ndev_dev(privdata), "%s id: %d\n", __func__,
+ i2c_common->bus_id);
+
+ i2c_cmd_base.ul = 0;
+ i2c_cmd_base.s.i2c_cmd = enable ? i2c_enable : i2c_disable;
+ i2c_cmd_base.s.bus_id = i2c_common->bus_id;
+ i2c_cmd_base.s.i2c_speed = i2c_common->i2c_speed;
+
+ amd_mp2_c2p_mutex_lock(i2c_common);
+
+ return amd_mp2_cmd(i2c_common, i2c_cmd_base);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_bus_enable_set);
+
+static void amd_mp2_cmd_rw_fill(struct amd_i2c_common *i2c_common,
+ union i2c_cmd_base *i2c_cmd_base,
+ enum i2c_cmd reqcmd)
+{
+ i2c_cmd_base->s.i2c_cmd = reqcmd;
+ i2c_cmd_base->s.bus_id = i2c_common->bus_id;
+ i2c_cmd_base->s.i2c_speed = i2c_common->i2c_speed;
+ i2c_cmd_base->s.slave_addr = i2c_common->msg->addr;
+ i2c_cmd_base->s.length = i2c_common->msg->len;
+}
+
+int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ union i2c_cmd_base i2c_cmd_base;
+
+ amd_mp2_cmd_rw_fill(i2c_common, &i2c_cmd_base, reqcmd);
+ amd_mp2_c2p_mutex_lock(i2c_common);
+
+ if (i2c_common->msg->len <= 32) {
+ i2c_cmd_base.s.mem_type = use_c2pmsg;
+ if (reqcmd == i2c_write)
+ memcpy_toio(privdata->mmio + AMD_C2P_MSG2,
+ i2c_common->msg->buf,
+ i2c_common->msg->len);
+ } else {
+ i2c_cmd_base.s.mem_type = use_dram;
+ writeq((u64)i2c_common->dma_addr,
+ privdata->mmio + AMD_C2P_MSG2);
+ }
+
+ return amd_mp2_cmd(i2c_common, i2c_cmd_base);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_rw);
+
+static void amd_mp2_pci_check_rw_event(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ int len = i2c_common->eventval.r.length;
+ u32 slave_addr = i2c_common->eventval.r.slave_addr;
+ bool err = false;
+
+ if (unlikely(len != i2c_common->msg->len)) {
+ dev_err(ndev_dev(privdata),
+ "length %d in event doesn't match buffer length %d!\n",
+ len, i2c_common->msg->len);
+ err = true;
+ }
+
+ if (unlikely(slave_addr != i2c_common->msg->addr)) {
+ dev_err(ndev_dev(privdata),
+ "unexpected slave address %x (expected: %x)!\n",
+ slave_addr, i2c_common->msg->addr);
+ err = true;
+ }
+
+ if (!err)
+ i2c_common->cmd_success = true;
+}
+
+static void __amd_mp2_process_event(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+ enum status_type sts = i2c_common->eventval.r.status;
+ enum response_type res = i2c_common->eventval.r.response;
+ int len = i2c_common->eventval.r.length;
+
+ if (res != command_success) {
+ if (res != command_failed)
+ dev_err(ndev_dev(privdata), "invalid response to i2c command!\n");
+ return;
+ }
+
+ switch (i2c_common->reqcmd) {
+ case i2c_read:
+ if (sts == i2c_readcomplete_event) {
+ amd_mp2_pci_check_rw_event(i2c_common);
+ if (len <= 32)
+ memcpy_fromio(i2c_common->msg->buf,
+ privdata->mmio + AMD_C2P_MSG2,
+ len);
+ } else if (sts != i2c_readfail_event) {
+ dev_err(ndev_dev(privdata),
+ "invalid i2c status after read (%d)!\n", sts);
+ }
+ break;
+ case i2c_write:
+ if (sts == i2c_writecomplete_event)
+ amd_mp2_pci_check_rw_event(i2c_common);
+ else if (sts != i2c_writefail_event)
+ dev_err(ndev_dev(privdata),
+ "invalid i2c status after write (%d)!\n", sts);
+ break;
+ case i2c_enable:
+ if (sts == i2c_busenable_complete)
+ i2c_common->cmd_success = true;
+ else if (sts != i2c_busenable_failed)
+ dev_err(ndev_dev(privdata),
+ "invalid i2c status after bus enable (%d)!\n",
+ sts);
+ break;
+ case i2c_disable:
+ if (sts == i2c_busdisable_complete)
+ i2c_common->cmd_success = true;
+ else if (sts != i2c_busdisable_failed)
+ dev_err(ndev_dev(privdata),
+ "invalid i2c status after bus disable (%d)!\n",
+ sts);
+ break;
+ default:
+ break;
+ }
+}
+
+void amd_mp2_process_event(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ if (unlikely(i2c_common->reqcmd == i2c_none)) {
+ dev_warn(ndev_dev(privdata),
+ "received msg but no cmd was sent (bus = %d)!\n",
+ i2c_common->bus_id);
+ return;
+ }
+
+ __amd_mp2_process_event(i2c_common);
+
+ i2c_common->reqcmd = i2c_none;
+ amd_mp2_c2p_mutex_unlock(i2c_common);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_process_event);
+
+static irqreturn_t amd_mp2_irq_isr(int irq, void *dev)
+{
+ struct amd_mp2_dev *privdata = dev;
+ struct amd_i2c_common *i2c_common;
+ u32 val;
+ unsigned int bus_id;
+ void __iomem *reg;
+ enum irqreturn ret = IRQ_NONE;
+
+ for (bus_id = 0; bus_id < 2; bus_id++) {
+ i2c_common = privdata->busses[bus_id];
+ if (!i2c_common)
+ continue;
+
+ reg = privdata->mmio + ((bus_id == 0) ?
+ AMD_P2C_MSG1 : AMD_P2C_MSG2);
+ val = readl(reg);
+ if (val != 0) {
+ writel(0, reg);
+ writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+ i2c_common->eventval.ul = val;
+ i2c_common->cmd_completion(i2c_common);
+
+ ret = IRQ_HANDLED;
+ }
+ }
+
+ if (ret != IRQ_HANDLED) {
+ val = readl(privdata->mmio + AMD_P2C_MSG_INTEN);
+ if (val != 0) {
+ writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+ dev_warn(ndev_dev(privdata),
+ "received irq without message\n");
+ ret = IRQ_HANDLED;
+ }
+ }
+
+ return ret;
+}
+
+void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common)
+{
+ i2c_common->reqcmd = i2c_none;
+ amd_mp2_c2p_mutex_unlock(i2c_common);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_rw_timeout);
+
+int amd_mp2_register_cb(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ if (i2c_common->bus_id > 1)
+ return -EINVAL;
+
+ if (privdata->busses[i2c_common->bus_id]) {
+ dev_err(ndev_dev(privdata),
+ "Bus %d already taken!\n", i2c_common->bus_id);
+ return -EINVAL;
+ }
+
+ privdata->busses[i2c_common->bus_id] = i2c_common;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(amd_mp2_register_cb);
+
+int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common)
+{
+ struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+ privdata->busses[i2c_common->bus_id] = NULL;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(amd_mp2_unregister_cb);
+
+static void amd_mp2_clear_reg(struct amd_mp2_dev *privdata)
+{
+ int reg;
+
+ for (reg = AMD_C2P_MSG0; reg <= AMD_C2P_MSG9; reg += 4)
+ writel(0, privdata->mmio + reg);
+
+ for (reg = AMD_P2C_MSG1; reg <= AMD_P2C_MSG2; reg += 4)
+ writel(0, privdata->mmio + reg);
+}
+
+static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
+ struct pci_dev *pci_dev)
+{
+ int rc;
+
+ pci_set_drvdata(pci_dev, privdata);
+
+ rc = pcim_enable_device(pci_dev);
+ if (rc) {
+ dev_err(ndev_dev(privdata), "Failed to enable MP2 PCI device\n");
+ goto err_pci_enable;
+ }
+
+ rc = pcim_iomap_regions(pci_dev, 1 << 2, pci_name(pci_dev));
+ if (rc) {
+ dev_err(ndev_dev(privdata), "I/O memory remapping failed\n");
+ goto err_pci_enable;
+ }
+ privdata->mmio = pcim_iomap_table(pci_dev)[2];
+
+ pci_set_master(pci_dev);
+
+ rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(64));
+ if (rc) {
+ rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
+ if (rc)
+ goto err_dma_mask;
+ }
+
+ /* Set up intx irq */
+ writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+ pci_intx(pci_dev, 1);
+ rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_mp2_irq_isr,
+ IRQF_SHARED, dev_name(&pci_dev->dev), privdata);
+ if (rc)
+ dev_err(&pci_dev->dev, "Failure requesting irq %i: %d\n",
+ pci_dev->irq, rc);
+
+ return rc;
+
+err_dma_mask:
+ pci_clear_master(pci_dev);
+err_pci_enable:
+ pci_set_drvdata(pci_dev, NULL);
+ return rc;
+}
+
+static int amd_mp2_pci_probe(struct pci_dev *pci_dev,
+ const struct pci_device_id *id)
+{
+ struct amd_mp2_dev *privdata;
+ int rc;
+
+ privdata = devm_kzalloc(&pci_dev->dev, sizeof(*privdata), GFP_KERNEL);
+ if (!privdata)
+ return -ENOMEM;
+
+ privdata->pci_dev = pci_dev;
+ rc = amd_mp2_pci_init(privdata, pci_dev);
+ if (rc)
+ return rc;
+
+ mutex_init(&privdata->c2p_lock);
+
+ 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);
+
+struct amd_mp2_dev *amd_mp2_find_device(void)
+{
+ struct device *dev;
+ struct pci_dev *pci_dev;
+
+ dev = driver_find_next_device(&amd_mp2_pci_driver.driver, NULL);
+ 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@amd.com>");
+MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>");
+MODULE_LICENSE("Dual BSD/GPL");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-12 16:46:16 +0000