We only implement io cycles here, we hook the lpc_io_write_byte and lpc_io_read_byte to inb/outb. So the drivers(ipmi/uart) which access the legacy ISA I/O port need no modification.
The low pin count specification is at http://www.intel.com/design/chipsets/industry/lpc.htm Signed-off-by: Rongrong Zou <zourongr...@gmail.com> --- arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/lpc.c | 294 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 295 insertions(+) create mode 100644 arch/arm64/kernel/lpc.c diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 474691f..4324575 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -41,6 +41,7 @@ arm64-obj-$(CONFIG_EFI) += efi.o efi-entry.stub.o arm64-obj-$(CONFIG_PCI) += pci.o arm64-obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o arm64-obj-$(CONFIG_ACPI) += acpi.o +arm64-obj-$(CONFIG_ARM64_INDIRECT_PIO) += lpc.o obj-y += $(arm64-obj-y) vdso/ obj-m += $(arm64-obj-m) diff --git a/arch/arm64/kernel/lpc.c b/arch/arm64/kernel/lpc.c new file mode 100644 index 0000000..174c293 --- /dev/null +++ b/arch/arm64/kernel/lpc.c @@ -0,0 +1,294 @@ +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> +#include <linux/version.h> + +#define LPC_REG_START (0x00) +#define LPC_REG_OP_STATUS (0x04) +#define LPC_REG_IRQ_ST (0x08) +#define LPC_REG_OP_LEN (0x10) +#define LPC_REG_CMD (0x14) +#define LPC_REG_FWH_ID_MSIZE (0x18) +#define LPC_REG_ADDR (0x20) +#define LPC_REG_WDATA (0x24) +#define LPC_REG_RDATA (0x28) +#define LPC_REG_LONG_CNT (0x30) +#define LPC_REG_TX_FIFO_ST (0x50) +#define LPC_REG_RX_FIFO_ST (0x54) +#define LPC_REG_TIME_OUT (0x58) +#define LPC_REG_STRQ_CTRL0 (0x80) +#define LPC_REG_STRQ_CTRL1 (0x84) +#define LPC_REG_STRQ_INT (0x90) +#define LPC_REG_STRQ_INT_MASK (0x94) +#define LPC_REG_STRQ_STAT (0xa0) + +#define LPC_CMD_SAMEADDR_SING (0x00000008) +#define LPC_CMD_SAMEADDR_INC (0x00000000) +#define LPC_CMD_TYPE_IO (0x00000000) +#define LPC_CMD_TYPE_MEM (0x00000002) +#define LPC_CMD_TYPE_FWH (0x00000004) +#define LPC_CMD_WRITE (0x00000001) +#define LPC_CMD_READ (0x00000000) + +#define LPC_IRQ_CLEAR (0x02) +#define LPC_IRQ_OCCURRED (0x02) +#define LPC_STATUS_DILE (0x01) +#define LPC_OP_FINISHED (0x02) +#define START_WORK (0x01) + +#define LPC_FRAME_LEN (0x10) + +#define LPC_CURR_STATUS_IDLE 0 +#define LPC_CURR_STATUS_START 1 +#define LPC_CURR_STATUS_TYPE_DIR 2 +#define LPC_CURR_STATUS_ADDR 3 +#define LPC_CURR_STATUS_MSIZE 4 +#define LPC_CURR_STATUS_WDATA 5 +#define LPC_CURR_STATUS_TARHOST 6 +#define LPC_CURR_STATUS_SYNC 7 +#define LPC_CURR_STATUS_RDATA 8 +#define LPC_CURR_STATUS_TARSLAVE 9 +#define LPC_CURR_STATUS_ABORT 10 + +struct lpc_dev { + spinlock_t lock; + void __iomem *regs; + struct device *dev; +}; + +static struct lpc_dev *lpc_dev; + +int lpc_master_write(unsigned int slv_access_mode, unsigned int cycle_type, + unsigned int addr, unsigned char *buf, unsigned int len) +{ + unsigned int i; + unsigned int lpc_cmd_value; + unsigned int lpc_op_state_value; + unsigned int retry = 0; + + /* para check */ + if (!buf || !len) + return -EINVAL; + + if (slv_access_mode != LPC_CMD_SAMEADDR_SING && + slv_access_mode != LPC_CMD_SAMEADDR_INC) { + return -EINVAL; + } + + if ((cycle_type != LPC_CMD_TYPE_IO) && + (cycle_type != LPC_CMD_TYPE_MEM) && + (cycle_type != LPC_CMD_TYPE_FWH)) { + return -EINVAL; + } + + writel(LPC_IRQ_CLEAR, lpc_dev->regs + LPC_REG_IRQ_ST); + retry = 0; + while (!(readl(lpc_dev->regs + LPC_REG_OP_STATUS) + & LPC_STATUS_DILE)) { + udelay(1); + retry++; + if (retry >= 2) + return -ETIME; + } + + /* set lpc master write cycle type and slv access mode */ + lpc_cmd_value = LPC_CMD_WRITE | cycle_type | slv_access_mode; + writel(lpc_cmd_value, lpc_dev->regs + LPC_REG_CMD); + + /* set lpc op len */ + writel(len, lpc_dev->regs + LPC_REG_OP_LEN); + + /* Set write data */ + for (i = 0; i < len; i++) + writel(buf[i], lpc_dev->regs + LPC_REG_WDATA); + + /* set lpc addr config */ + writel(addr, lpc_dev->regs + LPC_REG_ADDR); + + /* set lpc start work */ + writel(START_WORK, lpc_dev->regs + LPC_REG_START); + + retry = 0; + while (!(readl(lpc_dev->regs + LPC_REG_IRQ_ST) & + LPC_IRQ_OCCURRED)) { + udelay(1); + retry++; + if (retry >= 2) + return -ETIME; + } + + writel(LPC_IRQ_CLEAR, lpc_dev->regs + LPC_REG_IRQ_ST); + + lpc_op_state_value = readl(lpc_dev->regs + LPC_REG_OP_STATUS); + if (lpc_op_state_value & LPC_OP_FINISHED) + return 0; + + return -EIO; +} + +void lpc_io_write_byte(u8 value, unsigned long addr) +{ + unsigned long flags; + + if (!lpc_dev) + return; + spin_lock_irqsave(&lpc_dev->lock, flags); + (void)lpc_master_write(LPC_CMD_SAMEADDR_SING, LPC_CMD_TYPE_IO, + addr, &value, 1); + spin_unlock_irqrestore(&lpc_dev->lock, flags); +} + +int lpc_master_read(unsigned int slv_access_mode, unsigned int cycle_type, + unsigned int addr, unsigned char *buf, unsigned int len) +{ + unsigned int i; + unsigned int lpc_cmd_value; + unsigned int lpc_op_state_value; + unsigned int retry = 0; + + /* para check */ + if (!buf || !len) + return -EINVAL; + + if (slv_access_mode != LPC_CMD_SAMEADDR_SING && + slv_access_mode != LPC_CMD_SAMEADDR_INC) { + return -EINVAL; + } + + if (cycle_type != LPC_CMD_TYPE_IO && + cycle_type != LPC_CMD_TYPE_MEM && + cycle_type != LPC_CMD_TYPE_FWH) { + return -EINVAL; + } + + writel(LPC_IRQ_CLEAR, lpc_dev->regs + LPC_REG_IRQ_ST); + + retry = 0; + while (!(readl(lpc_dev->regs + LPC_REG_OP_STATUS) & + LPC_STATUS_DILE)) { + udelay(1); + retry++; + if (retry >= 2) + return -ETIME; + } + + /* set lpc master read cycle type and slv access mode */ + lpc_cmd_value = LPC_CMD_READ | cycle_type | slv_access_mode; + writel(lpc_cmd_value, lpc_dev->regs + LPC_REG_CMD); + + /* set lpc op len */ + writel(len, lpc_dev->regs + LPC_REG_OP_LEN); + + /* set lpc addr config */ + writel(addr, lpc_dev->regs + LPC_REG_ADDR); + + /* set lpc start work */ + writel(START_WORK, lpc_dev->regs + LPC_REG_START); + + while (!(readl(lpc_dev->regs + LPC_REG_IRQ_ST) & + LPC_IRQ_OCCURRED)) { + udelay(1); + retry++; + if (retry >= 2) + return -ETIME; + } + + writel(LPC_IRQ_CLEAR, lpc_dev->regs + LPC_REG_IRQ_ST); + + lpc_op_state_value = readl(lpc_dev->regs + LPC_REG_OP_STATUS); + /* Get read data */ + if (lpc_op_state_value & LPC_OP_FINISHED) { + for (i = 0; i < len; i++) + buf[i] = readl(lpc_dev->regs + LPC_REG_RDATA); + return 0; + } + return -EIO; +} + +u8 lpc_io_read_byte(unsigned long addr) +{ + unsigned char value; + unsigned long flags; + int ret; + + if (!lpc_dev) + return 0xff; + + spin_lock_irqsave(&lpc_dev->lock, flags); + ret = lpc_master_read(LPC_CMD_SAMEADDR_SING, + LPC_CMD_TYPE_IO, addr, &value, 1); + spin_unlock_irqrestore(&lpc_dev->lock, flags); + return ret ? 0xff : value; +} + +static const struct arm64_isa_io lpc_io = { + .inb = lpc_io_read_byte, + .outb = lpc_io_write_byte, +}; + +static int lpc_probe(struct platform_device *pdev) +{ + struct resource *regs = NULL; + + lpc_dev = devm_kzalloc(&pdev->dev, + sizeof(struct lpc_dev), GFP_KERNEL); + if (!lpc_dev) + return -ENOMEM; + + spin_lock_init(&lpc_dev->lock); + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + lpc_dev->regs = devm_ioremap_resource(&pdev->dev, regs); + if (IS_ERR(lpc_dev->regs)) + return PTR_ERR(lpc_dev->regs); + + dev_info(&pdev->dev, "Low pin count driver initialized successfully\n"); + + lpc_dev->dev = &pdev->dev; + platform_set_drvdata(pdev, lpc_dev); + arm64_isa_io = lpc_io; + + return 0; +} + +static int lpc_remove(struct platform_device *pdev) +{ + return 0; +} + +static const struct of_device_id lpc_pltfm_match[] = { + { + .compatible = "low-pin-count", + }, + {}, +}; + +static struct platform_driver lpc_driver = { + .driver = { + .name = "LPC", + .owner = THIS_MODULE, + .of_match_table = lpc_pltfm_match, + }, + .probe = lpc_probe, + .remove = lpc_remove, +}; + +static int __init lpc_init_driver(void) +{ + return platform_driver_register(&lpc_driver); +} + +static void __exit lpc_init_exit(void) +{ + platform_driver_unregister(&lpc_driver); +} + +arch_initcall(lpc_init_driver); +module_exit(lpc_init_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Huawei Tech. Co., Ltd."); +MODULE_DESCRIPTION("LPC driver for linux"); +MODULE_VERSION("v1.0"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
