diff options
Diffstat (limited to 'drivers/platform/x86/intel_scu_ipc.c')
| -rw-r--r-- | drivers/platform/x86/intel_scu_ipc.c | 725 |
1 files changed, 725 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c new file mode 100644 index 0000000000..a68df41334 --- /dev/null +++ b/drivers/platform/x86/intel_scu_ipc.c @@ -0,0 +1,725 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for the Intel SCU IPC mechanism + * + * (C) Copyright 2008-2010,2015 Intel Corporation + * Author: Sreedhara DS (sreedhara.ds@intel.com) + * + * SCU running in ARC processor communicates with other entity running in IA + * core through IPC mechanism which in turn messaging between IA core ad SCU. + * SCU has two IPC mechanism IPC-1 and IPC-2. IPC-1 is used between IA32 and + * SCU where IPC-2 is used between P-Unit and SCU. This driver delas with + * IPC-1 Driver provides an API for power control unit registers (e.g. MSIC) + * along with other APIs. + */ + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include <asm/intel_scu_ipc.h> + +/* IPC defines the following message types */ +#define IPCMSG_PCNTRL 0xff /* Power controller unit read/write */ + +/* Command id associated with message IPCMSG_PCNTRL */ +#define IPC_CMD_PCNTRL_W 0 /* Register write */ +#define IPC_CMD_PCNTRL_R 1 /* Register read */ +#define IPC_CMD_PCNTRL_M 2 /* Register read-modify-write */ + +/* + * IPC register summary + * + * IPC register blocks are memory mapped at fixed address of PCI BAR 0. + * To read or write information to the SCU, driver writes to IPC-1 memory + * mapped registers. The following is the IPC mechanism + * + * 1. IA core cDMI interface claims this transaction and converts it to a + * Transaction Layer Packet (TLP) message which is sent across the cDMI. + * + * 2. South Complex cDMI block receives this message and writes it to + * the IPC-1 register block, causing an interrupt to the SCU + * + * 3. SCU firmware decodes this interrupt and IPC message and the appropriate + * message handler is called within firmware. + */ + +#define IPC_WWBUF_SIZE 20 /* IPC Write buffer Size */ +#define IPC_RWBUF_SIZE 20 /* IPC Read buffer Size */ +#define IPC_IOC 0x100 /* IPC command register IOC bit */ + +struct intel_scu_ipc_dev { + struct device dev; + struct resource mem; + struct module *owner; + int irq; + void __iomem *ipc_base; + struct completion cmd_complete; +}; + +#define IPC_STATUS 0x04 +#define IPC_STATUS_IRQ BIT(2) +#define IPC_STATUS_ERR BIT(1) +#define IPC_STATUS_BUSY BIT(0) + +/* + * IPC Write/Read Buffers: + * 16 byte buffer for sending and receiving data to and from SCU. + */ +#define IPC_WRITE_BUFFER 0x80 +#define IPC_READ_BUFFER 0x90 + +/* Timeout in jiffies */ +#define IPC_TIMEOUT (10 * HZ) + +static struct intel_scu_ipc_dev *ipcdev; /* Only one for now */ +static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */ + +static struct class intel_scu_ipc_class = { + .name = "intel_scu_ipc", +}; + +/** + * intel_scu_ipc_dev_get() - Get SCU IPC instance + * + * The recommended new API takes SCU IPC instance as parameter and this + * function can be called by driver to get the instance. This also makes + * sure the driver providing the IPC functionality cannot be unloaded + * while the caller has the instance. + * + * Call intel_scu_ipc_dev_put() to release the instance. + * + * Returns %NULL if SCU IPC is not currently available. + */ +struct intel_scu_ipc_dev *intel_scu_ipc_dev_get(void) +{ + struct intel_scu_ipc_dev *scu = NULL; + + mutex_lock(&ipclock); + if (ipcdev) { + get_device(&ipcdev->dev); + /* + * Prevent the IPC provider from being unloaded while it + * is being used. + */ + if (!try_module_get(ipcdev->owner)) + put_device(&ipcdev->dev); + else + scu = ipcdev; + } + + mutex_unlock(&ipclock); + return scu; +} +EXPORT_SYMBOL_GPL(intel_scu_ipc_dev_get); + +/** + * intel_scu_ipc_dev_put() - Put SCU IPC instance + * @scu: SCU IPC instance + * + * This function releases the SCU IPC instance retrieved from + * intel_scu_ipc_dev_get() and allows the driver providing IPC to be + * unloaded. + */ +void intel_scu_ipc_dev_put(struct intel_scu_ipc_dev *scu) +{ + if (scu) { + module_put(scu->owner); + put_device(&scu->dev); + } +} +EXPORT_SYMBOL_GPL(intel_scu_ipc_dev_put); + +struct intel_scu_ipc_devres { + struct intel_scu_ipc_dev *scu; +}; + +static void devm_intel_scu_ipc_dev_release(struct device *dev, void *res) +{ + struct intel_scu_ipc_devres *dr = res; + struct intel_scu_ipc_dev *scu = dr->scu; + + intel_scu_ipc_dev_put(scu); +} + +/** + * devm_intel_scu_ipc_dev_get() - Allocate managed SCU IPC device + * @dev: Device requesting the SCU IPC device + * + * The recommended new API takes SCU IPC instance as parameter and this + * function can be called by driver to get the instance. This also makes + * sure the driver providing the IPC functionality cannot be unloaded + * while the caller has the instance. + * + * Returns %NULL if SCU IPC is not currently available. + */ +struct intel_scu_ipc_dev *devm_intel_scu_ipc_dev_get(struct device *dev) +{ + struct intel_scu_ipc_devres *dr; + struct intel_scu_ipc_dev *scu; + + dr = devres_alloc(devm_intel_scu_ipc_dev_release, sizeof(*dr), GFP_KERNEL); + if (!dr) + return NULL; + + scu = intel_scu_ipc_dev_get(); + if (!scu) { + devres_free(dr); + return NULL; + } + + dr->scu = scu; + devres_add(dev, dr); + + return scu; +} +EXPORT_SYMBOL_GPL(devm_intel_scu_ipc_dev_get); + +/* + * Send ipc command + * Command Register (Write Only): + * A write to this register results in an interrupt to the SCU core processor + * Format: + * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)| + */ +static inline void ipc_command(struct intel_scu_ipc_dev *scu, u32 cmd) +{ + reinit_completion(&scu->cmd_complete); + writel(cmd | IPC_IOC, scu->ipc_base); +} + +/* + * Write ipc data + * IPC Write Buffer (Write Only): + * 16-byte buffer for sending data associated with IPC command to + * SCU. Size of the data is specified in the IPC_COMMAND_REG register + */ +static inline void ipc_data_writel(struct intel_scu_ipc_dev *scu, u32 data, u32 offset) +{ + writel(data, scu->ipc_base + IPC_WRITE_BUFFER + offset); +} + +/* + * Status Register (Read Only): + * Driver will read this register to get the ready/busy status of the IPC + * block and error status of the IPC command that was just processed by SCU + * Format: + * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)| + */ +static inline u8 ipc_read_status(struct intel_scu_ipc_dev *scu) +{ + return __raw_readl(scu->ipc_base + IPC_STATUS); +} + +/* Read ipc byte data */ +static inline u8 ipc_data_readb(struct intel_scu_ipc_dev *scu, u32 offset) +{ + return readb(scu->ipc_base + IPC_READ_BUFFER + offset); +} + +/* Read ipc u32 data */ +static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset) +{ + return readl(scu->ipc_base + IPC_READ_BUFFER + offset); +} + +/* Wait till scu status is busy */ +static inline int busy_loop(struct intel_scu_ipc_dev *scu) +{ + u8 status; + int err; + + err = readx_poll_timeout(ipc_read_status, scu, status, !(status & IPC_STATUS_BUSY), + 100, jiffies_to_usecs(IPC_TIMEOUT)); + if (err) + return err; + + return (status & IPC_STATUS_ERR) ? -EIO : 0; +} + +/* Wait till ipc ioc interrupt is received or timeout in 10 HZ */ +static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu) +{ + int status; + + wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT); + + status = ipc_read_status(scu); + if (status & IPC_STATUS_BUSY) + return -ETIMEDOUT; + + if (status & IPC_STATUS_ERR) + return -EIO; + + return 0; +} + +static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu) +{ + return scu->irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu); +} + +static struct intel_scu_ipc_dev *intel_scu_ipc_get(struct intel_scu_ipc_dev *scu) +{ + u8 status; + + if (!scu) + scu = ipcdev; + if (!scu) + return ERR_PTR(-ENODEV); + + status = ipc_read_status(scu); + if (status & IPC_STATUS_BUSY) { + dev_dbg(&scu->dev, "device is busy\n"); + return ERR_PTR(-EBUSY); + } + + return scu; +} + +/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */ +static int pwr_reg_rdwr(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data, + u32 count, u32 op, u32 id) +{ + int nc; + u32 offset = 0; + int err; + u8 cbuf[IPC_WWBUF_SIZE]; + u32 *wbuf = (u32 *)&cbuf; + + memset(cbuf, 0, sizeof(cbuf)); + + mutex_lock(&ipclock); + scu = intel_scu_ipc_get(scu); + if (IS_ERR(scu)) { + mutex_unlock(&ipclock); + return PTR_ERR(scu); + } + + for (nc = 0; nc < count; nc++, offset += 2) { + cbuf[offset] = addr[nc]; + cbuf[offset + 1] = addr[nc] >> 8; + } + + if (id == IPC_CMD_PCNTRL_R) { + for (nc = 0, offset = 0; nc < count; nc++, offset += 4) + ipc_data_writel(scu, wbuf[nc], offset); + ipc_command(scu, (count * 2) << 16 | id << 12 | 0 << 8 | op); + } else if (id == IPC_CMD_PCNTRL_W) { + for (nc = 0; nc < count; nc++, offset += 1) + cbuf[offset] = data[nc]; + for (nc = 0, offset = 0; nc < count; nc++, offset += 4) + ipc_data_writel(scu, wbuf[nc], offset); + ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op); + } else if (id == IPC_CMD_PCNTRL_M) { + cbuf[offset] = data[0]; + cbuf[offset + 1] = data[1]; + ipc_data_writel(scu, wbuf[0], 0); /* Write wbuff */ + ipc_command(scu, 4 << 16 | id << 12 | 0 << 8 | op); + } + + err = intel_scu_ipc_check_status(scu); + if (!err && id == IPC_CMD_PCNTRL_R) { /* Read rbuf */ + /* Workaround: values are read as 0 without memcpy_fromio */ + memcpy_fromio(cbuf, scu->ipc_base + 0x90, 16); + for (nc = 0; nc < count; nc++) + data[nc] = ipc_data_readb(scu, nc); + } + mutex_unlock(&ipclock); + return err; +} + +/** + * intel_scu_ipc_dev_ioread8() - Read a byte via the SCU + * @scu: Optional SCU IPC instance + * @addr: Register on SCU + * @data: Return pointer for read byte + * + * Read a single register. Returns %0 on success or an error code. All + * locking between SCU accesses is handled for the caller. + * + * This function may sleep. + */ +int intel_scu_ipc_dev_ioread8(struct intel_scu_ipc_dev *scu, u16 addr, u8 *data) +{ + return pwr_reg_rdwr(scu, &addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R); +} +EXPORT_SYMBOL(intel_scu_ipc_dev_ioread8); + +/** + * intel_scu_ipc_dev_iowrite8() - Write a byte via the SCU + * @scu: Optional SCU IPC instance + * @addr: Register on SCU + * @data: Byte to write + * + * Write a single register. Returns %0 on success or an error code. All + * locking between SCU accesses is handled for the caller. + * + * This function may sleep. + */ +int intel_scu_ipc_dev_iowrite8(struct intel_scu_ipc_dev *scu, u16 addr, u8 data) +{ + return pwr_reg_rdwr(scu, &addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W); +} +EXPORT_SYMBOL(intel_scu_ipc_dev_iowrite8); + +/** + * intel_scu_ipc_dev_readv() - Read a set of registers + * @scu: Optional SCU IPC instance + * @addr: Register list + * @data: Bytes to return + * @len: Length of array + * + * Read registers. Returns %0 on success or an error code. All locking + * between SCU accesses is handled for the caller. + * + * The largest array length permitted by the hardware is 5 items. + * + * This function may sleep. + */ +int intel_scu_ipc_dev_readv(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data, + size_t len) +{ + return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R); +} +EXPORT_SYMBOL(intel_scu_ipc_dev_readv); + +/** + * intel_scu_ipc_dev_writev() - Write a set of registers + * @scu: Optional SCU IPC instance + * @addr: Register list + * @data: Bytes to write + * @len: Length of array + * + * Write registers. Returns %0 on success or an error code. All locking + * between SCU accesses is handled for the caller. + * + * The largest array length permitted by the hardware is 5 items. + * + * This function may sleep. + */ +int intel_scu_ipc_dev_writev(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data, + size_t len) +{ + return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W); +} +EXPORT_SYMBOL(intel_scu_ipc_dev_writev); + +/** + * intel_scu_ipc_dev_update() - Update a register + * @scu: Optional SCU IPC instance + * @addr: Register address + * @data: Bits to update + * @mask: Mask of bits to update + * + * Read-modify-write power control unit register. The first data argument + * must be register value and second is mask value mask is a bitmap that + * indicates which bits to update. %0 = masked. Don't modify this bit, %1 = + * modify this bit. returns %0 on success or an error code. + * + * This function may sleep. Locking between SCU accesses is handled + * for the caller. + */ +int intel_scu_ipc_dev_update(struct intel_scu_ipc_dev *scu, u16 addr, u8 data, + u8 mask) +{ + u8 tmp[2] = { data, mask }; + return pwr_reg_rdwr(scu, &addr, tmp, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M); +} +EXPORT_SYMBOL(intel_scu_ipc_dev_update); + +/** + * intel_scu_ipc_dev_simple_command() - Send a simple command + * @scu: Optional SCU IPC instance + * @cmd: Command + * @sub: Sub type + * + * Issue a simple command to the SCU. Do not use this interface if you must + * then access data as any data values may be overwritten by another SCU + * access by the time this function returns. + * + * This function may sleep. Locking for SCU accesses is handled for the + * caller. + */ +int intel_scu_ipc_dev_simple_command(struct intel_scu_ipc_dev *scu, int cmd, + int sub) +{ + u32 cmdval; + int err; + + mutex_lock(&ipclock); + scu = intel_scu_ipc_get(scu); + if (IS_ERR(scu)) { + mutex_unlock(&ipclock); + return PTR_ERR(scu); + } + + cmdval = sub << 12 | cmd; + ipc_command(scu, cmdval); + err = intel_scu_ipc_check_status(scu); + mutex_unlock(&ipclock); + if (err) + dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err); + return err; +} +EXPORT_SYMBOL(intel_scu_ipc_dev_simple_command); + +/** + * intel_scu_ipc_dev_command_with_size() - Command with data + * @scu: Optional SCU IPC instance + * @cmd: Command + * @sub: Sub type + * @in: Input data + * @inlen: Input length in bytes + * @size: Input size written to the IPC command register in whatever + * units (dword, byte) the particular firmware requires. Normally + * should be the same as @inlen. + * @out: Output data + * @outlen: Output length in bytes + * + * Issue a command to the SCU which involves data transfers. Do the + * data copies under the lock but leave it for the caller to interpret. + */ +int intel_scu_ipc_dev_command_with_size(struct intel_scu_ipc_dev *scu, int cmd, + int sub, const void *in, size_t inlen, + size_t size, void *out, size_t outlen) +{ + size_t outbuflen = DIV_ROUND_UP(outlen, sizeof(u32)); + size_t inbuflen = DIV_ROUND_UP(inlen, sizeof(u32)); + u32 cmdval, inbuf[4] = {}; + int i, err; + + if (inbuflen > 4 || outbuflen > 4) + return -EINVAL; + + mutex_lock(&ipclock); + scu = intel_scu_ipc_get(scu); + if (IS_ERR(scu)) { + mutex_unlock(&ipclock); + return PTR_ERR(scu); + } + + memcpy(inbuf, in, inlen); + for (i = 0; i < inbuflen; i++) + ipc_data_writel(scu, inbuf[i], 4 * i); + + cmdval = (size << 16) | (sub << 12) | cmd; + ipc_command(scu, cmdval); + err = intel_scu_ipc_check_status(scu); + + if (!err) { + u32 outbuf[4] = {}; + + for (i = 0; i < outbuflen; i++) + outbuf[i] = ipc_data_readl(scu, 4 * i); + + memcpy(out, outbuf, outlen); + } + + mutex_unlock(&ipclock); + if (err) + dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err); + return err; +} +EXPORT_SYMBOL(intel_scu_ipc_dev_command_with_size); + +/* + * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1 + * When ioc bit is set to 1, caller api must wait for interrupt handler called + * which in turn unlocks the caller api. Currently this is not used + * + * This is edge triggered so we need take no action to clear anything + */ +static irqreturn_t ioc(int irq, void *dev_id) +{ + struct intel_scu_ipc_dev *scu = dev_id; + int status = ipc_read_status(scu); + + writel(status | IPC_STATUS_IRQ, scu->ipc_base + IPC_STATUS); + complete(&scu->cmd_complete); + + return IRQ_HANDLED; +} + +static void intel_scu_ipc_release(struct device *dev) +{ + struct intel_scu_ipc_dev *scu; + + scu = container_of(dev, struct intel_scu_ipc_dev, dev); + if (scu->irq > 0) + free_irq(scu->irq, scu); + iounmap(scu->ipc_base); + release_mem_region(scu->mem.start, resource_size(&scu->mem)); + kfree(scu); +} + +/** + * __intel_scu_ipc_register() - Register SCU IPC device + * @parent: Parent device + * @scu_data: Data used to configure SCU IPC + * @owner: Module registering the SCU IPC device + * + * Call this function to register SCU IPC mechanism under @parent. + * Returns pointer to the new SCU IPC device or ERR_PTR() in case of + * failure. The caller may use the returned instance if it needs to do + * SCU IPC calls itself. + */ +struct intel_scu_ipc_dev * +__intel_scu_ipc_register(struct device *parent, + const struct intel_scu_ipc_data *scu_data, + struct module *owner) +{ + int err; + struct intel_scu_ipc_dev *scu; + void __iomem *ipc_base; + + mutex_lock(&ipclock); + /* We support only one IPC */ + if (ipcdev) { + err = -EBUSY; + goto err_unlock; + } + + scu = kzalloc(sizeof(*scu), GFP_KERNEL); + if (!scu) { + err = -ENOMEM; + goto err_unlock; + } + + scu->owner = owner; + scu->dev.parent = parent; + scu->dev.class = &intel_scu_ipc_class; + scu->dev.release = intel_scu_ipc_release; + + if (!request_mem_region(scu_data->mem.start, resource_size(&scu_data->mem), + "intel_scu_ipc")) { + err = -EBUSY; + goto err_free; + } + + ipc_base = ioremap(scu_data->mem.start, resource_size(&scu_data->mem)); + if (!ipc_base) { + err = -ENOMEM; + goto err_release; + } + + scu->ipc_base = ipc_base; + scu->mem = scu_data->mem; + scu->irq = scu_data->irq; + init_completion(&scu->cmd_complete); + + if (scu->irq > 0) { + err = request_irq(scu->irq, ioc, 0, "intel_scu_ipc", scu); + if (err) + goto err_unmap; + } + + /* + * After this point intel_scu_ipc_release() takes care of + * releasing the SCU IPC resources once refcount drops to zero. + */ + dev_set_name(&scu->dev, "intel_scu_ipc"); + err = device_register(&scu->dev); + if (err) { + put_device(&scu->dev); + goto err_unlock; + } + + /* Assign device at last */ + ipcdev = scu; + mutex_unlock(&ipclock); + + return scu; + +err_unmap: + iounmap(ipc_base); +err_release: + release_mem_region(scu_data->mem.start, resource_size(&scu_data->mem)); +err_free: + kfree(scu); +err_unlock: + mutex_unlock(&ipclock); + + return ERR_PTR(err); +} +EXPORT_SYMBOL_GPL(__intel_scu_ipc_register); + +/** + * intel_scu_ipc_unregister() - Unregister SCU IPC + * @scu: SCU IPC handle + * + * This unregisters the SCU IPC device and releases the acquired + * resources once the refcount goes to zero. + */ +void intel_scu_ipc_unregister(struct intel_scu_ipc_dev *scu) +{ + mutex_lock(&ipclock); + if (!WARN_ON(!ipcdev)) { + ipcdev = NULL; + device_unregister(&scu->dev); + } + mutex_unlock(&ipclock); +} +EXPORT_SYMBOL_GPL(intel_scu_ipc_unregister); + +static void devm_intel_scu_ipc_unregister(struct device *dev, void *res) +{ + struct intel_scu_ipc_devres *dr = res; + struct intel_scu_ipc_dev *scu = dr->scu; + + intel_scu_ipc_unregister(scu); +} + +/** + * __devm_intel_scu_ipc_register() - Register managed SCU IPC device + * @parent: Parent device + * @scu_data: Data used to configure SCU IPC + * @owner: Module registering the SCU IPC device + * + * Call this function to register managed SCU IPC mechanism under + * @parent. Returns pointer to the new SCU IPC device or ERR_PTR() in + * case of failure. The caller may use the returned instance if it needs + * to do SCU IPC calls itself. + */ +struct intel_scu_ipc_dev * +__devm_intel_scu_ipc_register(struct device *parent, + const struct intel_scu_ipc_data *scu_data, + struct module *owner) +{ + struct intel_scu_ipc_devres *dr; + struct intel_scu_ipc_dev *scu; + + dr = devres_alloc(devm_intel_scu_ipc_unregister, sizeof(*dr), GFP_KERNEL); + if (!dr) + return NULL; + + scu = __intel_scu_ipc_register(parent, scu_data, owner); + if (IS_ERR(scu)) { + devres_free(dr); + return scu; + } + + dr->scu = scu; + devres_add(parent, dr); + + return scu; +} +EXPORT_SYMBOL_GPL(__devm_intel_scu_ipc_register); + +static int __init intel_scu_ipc_init(void) +{ + return class_register(&intel_scu_ipc_class); +} +subsys_initcall(intel_scu_ipc_init); + +static void __exit intel_scu_ipc_exit(void) +{ + class_unregister(&intel_scu_ipc_class); +} +module_exit(intel_scu_ipc_exit); |