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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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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-pci.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-amd-mp2-pci.c')
-rw-r--r-- | drivers/i2c/busses/i2c-amd-mp2-pci.c | 465 |
1 files changed, 465 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..f57077a74 --- /dev/null +++ b/drivers/i2c/busses/i2c-amd-mp2-pci.c @@ -0,0 +1,465 @@ +// 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)) { + pci_warn(privdata->pci_dev, + "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; + + pci_dbg(privdata->pci_dev, "id: %d\n", 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; + struct pci_dev *pdev = privdata->pci_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)) { + pci_err(pdev, "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)) { + pci_err(pdev, "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; + struct pci_dev *pdev = privdata->pci_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) + pci_err(pdev, "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) { + pci_err(pdev, "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) + pci_err(pdev, "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) + pci_err(pdev, "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) + pci_err(pdev, "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; + struct pci_dev *pdev = privdata->pci_dev; + + if (unlikely(i2c_common->reqcmd == i2c_none)) { + pci_warn(pdev, "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 pci_dev *pdev = privdata->pci_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); + pci_warn(pdev, "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; + struct pci_dev *pdev = privdata->pci_dev; + + if (i2c_common->bus_id > 1) + return -EINVAL; + + if (privdata->busses[i2c_common->bus_id]) { + pci_err(pdev, "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) { + pci_err(pci_dev, "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) { + pci_err(pci_dev, "I/O memory remapping failed\n"); + goto err_pci_enable; + } + privdata->mmio = pcim_iomap_table(pci_dev)[2]; + + pci_set_master(pci_dev); + + rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64)); + 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) + pci_err(pci_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; + + pci_info(pci_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) { + pci_err(pci_dev, "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) { + pci_err(pci_dev, "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"); |