The KCS (Keyboard Controller Style) interface is used to perform in-band
IPMI communication between a server host and its BMC (BaseBoard Management
Controllers).
This driver exposes the KCS interface on ASpeed SOCs (AST2400 and AST2500)
as a character device. Such SOCs are commonly used as BMCs and this driver
implements the BMC side of the KCS interface.
Signed-off-by: Haiyue Wang <haiyue.w...@linux.intel.com>
---
.../devicetree/bindings/ipmi/aspeed-kcs-bmc.txt | 26 +
drivers/char/ipmi/Kconfig | 9 +
drivers/char/ipmi/Makefile | 1 +
drivers/char/ipmi/kcs-bmc.c | 744 +++++++++++++++++++++
include/uapi/linux/kcs-bmc.h | 14 +
5 files changed, 794 insertions(+)
create mode 100644 Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
create mode 100644 drivers/char/ipmi/kcs-bmc.c
create mode 100644 include/uapi/linux/kcs-bmc.h
diff --git a/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
b/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
new file mode 100644
index 0000000..dd0c73d
--- /dev/null
+++ b/Documentation/devicetree/bindings/ipmi/aspeed-kcs-bmc.txt
@@ -0,0 +1,26 @@
+* Aspeed KCS (Keyboard Controller Style) IPMI interface
+
+The Aspeed SOCs (AST2400 and AST2500) are commonly used as BMCs
+(BaseBoard Management Controllers) and the KCS interface can be
+used to perform in-band IPMI communication with their host.
+
+Required properties:
+- compatible : should be one of
+ "aspeed,ast2400-kcs-bmc"
+ "aspeed,ast2500-kcs-bmc"
+- interrupts : interrupt generated by the controller
+- kcs_chan : The LPC channel number in the controller
+- kcs_addr : The host CPU IO map address
+
+
+Example:
+
+ kcs3: kcs3@0 {
+ compatible = "aspeed,ast2500-kcs-bmc";
+ reg = <0x0 0x80>;
+ interrupts = <8>;
+ kcs_chan = <3>;
+ kcs_addr = <0xCA2>;
+ status = "okay";
+ };
+
diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 3544abc..36132f8 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -104,3 +104,12 @@ config ASPEED_BT_IPMI_BMC
Provides a driver for the BT (Block Transfer) IPMI interface
found on Aspeed SOCs (AST2400 and AST2500). The driver
implements the BMC side of the BT interface.
+
+config ASPEED_KCS_IPMI_BMC
+ depends on ARCH_ASPEED || COMPILE_TEST
+ select REGMAP_MMIO
+ tristate "KCS IPMI bmc driver"
+ help
+ Provides a driver for the KCS (Keyboard Controller Style) IPMI
+ interface found on Aspeed SOCs (AST2400 and AST2500). The driver
+ implements the BMC side of the KCS interface.
\ No newline at end of file
diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile
index 33b899f..f217bae 100644
--- a/drivers/char/ipmi/Makefile
+++ b/drivers/char/ipmi/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o
obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o
obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
+obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs-bmc.o
\ No newline at end of file
diff --git a/drivers/char/ipmi/kcs-bmc.c b/drivers/char/ipmi/kcs-bmc.c
new file mode 100644
index 0000000..d6eab0b
--- /dev/null
+++ b/drivers/char/ipmi/kcs-bmc.c
@@ -0,0 +1,744 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2015-2018, Intel Corporation.
+
+#include <linux/atomic.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kcs-bmc.h>
+#include <linux/mfd/syscon.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/regmap.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+
+#define KCS_MSG_BUFSIZ 1024
+#define KCS_CHANNEL_MAX 4
+
+/*
+ * This is a BMC device used to communicate to the host
+ */
+#define DEVICE_NAME "ipmi-kcs-host"
+
+
+/* Different Phases of the KCS Module */
+#define KCS_PHASE_IDLE 0x00
+#define KCS_PHASE_WRITE 0x01
+#define KCS_PHASE_WRITE_END 0x02
+#define KCS_PHASE_READ 0x03
+#define KCS_PHASE_ABORT 0x04
+#define KCS_PHASE_ERROR 0x05
+
+/* Abort Phase */
+#define ABORT_PHASE_ERROR1 0x01
+#define ABORT_PHASE_ERROR2 0x02
+
+/* KCS Command Control codes. */
+#define KCS_GET_STATUS 0x60
+#define KCS_ABORT 0x60
+#define KCS_WRITE_START 0x61
+#define KCS_WRITE_END 0x62
+#define KCS_READ_BYTE 0x68
+
+/* Status bits.:
+ * - IDLE_STATE. Interface is idle. System software should not be expecting
+ * nor sending any data.
+ * - READ_STATE. BMC is transferring a packet to system software. System
+ * software should be in the "Read Message" state.
+ * - WRITE_STATE. BMC is receiving a packet from system software. System
+ * software should be writing a command to the BMC.
+ * - ERROR_STATE. BMC has detected a protocol violation at the interface level,
+ * or the transfer has been aborted. System software can either
+ * use the "Get_Status" control code to request the nature of
+ * the error, or it can just retry the command.
+ */
+#define KCS_IDLE_STATE 0
+#define KCS_READ_STATE 1
+#define KCS_WRITE_STATE 2
+#define KCS_ERROR_STATE 3
+
+/* KCS Error Codes */
+#define KCS_NO_ERROR 0x00
+#define KCS_ABORTED_BY_COMMAND 0x01
+#define KCS_ILLEGAL_CONTROL_CODE 0x02
+#define KCS_LENGTH_ERROR 0x06
+#define KCS_UNSPECIFIED_ERROR 0xFF
+
+
+#define KCS_ZERO_DATA 0
+
+/* IPMI 2.0 - Table 9-1, KCS Interface Status Register Bits */
+#define KCS_STR_STATE(state) (state << 6)
+#define KCS_STR_STATE_MASK KCS_STR_STATE(0x3)
+#define KCS_STR_CMD_DAT BIT(3)
+#define KCS_STR_SMS_ATN BIT(2)
+#define KCS_STR_IBF BIT(1)
+#define KCS_STR_OBF BIT(0)
+
+
+/* mapped to lpc-bmc@0 IO space */
+#define LPC_HICR0 0x000
+#define LPC_HICR0_LPC3E BIT(7)
+#define LPC_HICR0_LPC2E BIT(6)
+#define LPC_HICR0_LPC1E BIT(5)
+#define LPC_HICR2 0x008
+#define LPC_HICR2_IBFIF3 BIT(3)
+#define LPC_HICR2_IBFIF2 BIT(2)
+#define LPC_HICR2_IBFIF1 BIT(1)
+#define LPC_HICR4 0x010
+#define LPC_HICR4_LADR12AS BIT(7)
+#define LPC_HICR4_KCSENBL BIT(2)
+#define LPC_LADR3H 0x014
+#define LPC_LADR3L 0x018
+#define LPC_LADR12H 0x01C
+#define LPC_LADR12L 0x020
+#define LPC_IDR1 0x024
+#define LPC_IDR2 0x028
+#define LPC_IDR3 0x02C
+#define LPC_ODR1 0x030
+#define LPC_ODR2 0x034
+#define LPC_ODR3 0x038
+#define LPC_STR1 0x03C
+#define LPC_STR2 0x040
+#define LPC_STR3 0x044
+
+/* mapped to lpc-host@80 IO space */
+#define LPC_HICRB 0x080
+#define LPC_HICRB_IBFIF4 BIT(1)
+#define LPC_HICRB_LPC4E BIT(0)
+#define LPC_LADR4 0x090
+#define LPC_IDR4 0x094
+#define LPC_ODR4 0x098
+#define LPC_STR4 0x09C
+
+
+/* IPMI 2.0 - 9.5, KCS Interface Registers */
+struct kcs_ioreg {
+ u32 idr; /* Input Data Register */
+ u32 odr; /* Output Data Register */
+ u32 str; /* Status Register */
+};
+
+static const struct kcs_ioreg kcs_ioreg_map[KCS_CHANNEL_MAX] = {
+ { .idr = LPC_IDR1, .odr = LPC_ODR1, .str = LPC_STR1 },
+ { .idr = LPC_IDR2, .odr = LPC_ODR2, .str = LPC_STR2 },
+ { .idr = LPC_IDR3, .odr = LPC_ODR3, .str = LPC_STR3 },
+ { .idr = LPC_IDR4, .odr = LPC_ODR4, .str = LPC_STR4 },
+};
+
+struct kcs_bmc {
+ struct regmap *map;
+ spinlock_t lock;
+
+ u32 chan;
+ int running;
+
+ u32 idr;
+ u32 odr;
+ u32 str;
+
+ int kcs_phase;
+ u8 abort_phase;
+ u8 kcs_error;
+
+ wait_queue_head_t queue;
+ int data_in_avail;
+ int data_in_idx;
+ u8 *data_in;
+
+ int data_out_idx;
+ int data_out_len;
+ u8 *data_out;
+
+ struct miscdevice miscdev;
+};
+
+static u8 kcs_inb(struct kcs_bmc *kcs_bmc, u32 reg)
+{
+ u32 val = 0;
+ int rc;
+
+ rc = regmap_read(kcs_bmc->map, reg, &val);
+ WARN(rc != 0, "regmap_read() failed: %d\n", rc);
+
+ return rc == 0 ? (u8) val : 0;
+}
+
+static void kcs_outb(struct kcs_bmc *kcs_bmc, u8 data, u32 reg)
+{
+ int rc;
+
+ rc = regmap_write(kcs_bmc->map, reg, data);
+ WARN(rc != 0, "regmap_write() failed: %d\n", rc);
+}
+
+static inline void kcs_set_state(struct kcs_bmc *kcs_bmc, u8 state)
+{
+ regmap_update_bits(kcs_bmc->map, kcs_bmc->str, KCS_STR_STATE_MASK,
+ KCS_STR_STATE(state));
+}
+
+static inline void kcs_set_atn(struct kcs_bmc *kcs_bmc)
+{
+ regmap_update_bits(kcs_bmc->map, kcs_bmc->str, KCS_STR_SMS_ATN,
+ KCS_STR_SMS_ATN);
+}
+
+static inline void kcs_clear_atn(struct kcs_bmc *kcs_bmc)
+{
+ regmap_update_bits(kcs_bmc->map, kcs_bmc->str, KCS_STR_SMS_ATN,
+ 0);
+}
+
+/*
+ * AST_usrGuide_KCS.pdf
+ * 2. Background:
+ * we note D for Data, and C for Cmd/Status, default rules are
+ * A. KCS1 / KCS2 ( D / C:X / X+4 )
+ * D / C : CA0h / CA4h
+ * D / C : CA8h / CACh
+ * B. KCS3 ( D / C:XX2h / XX3h )
+ * D / C : CA2h / CA3h
+ * D / C : CB2h / CB3h
+ * C. KCS4
+ * D / C : CA4h / CA5h
+ */
+static void kcs_set_addr(struct kcs_bmc *kcs_bmc, u16 addr)
+{
+ switch (kcs_bmc->chan) {
+ case 1:
+ regmap_update_bits(kcs_bmc->map, LPC_HICR4,
+ LPC_HICR4_LADR12AS, 0);
+ regmap_write(kcs_bmc->map, LPC_LADR12H, addr >> 8);
+ regmap_write(kcs_bmc->map, LPC_LADR12L, addr & 0xFF);
+ break;
+
+ case 2:
+ regmap_update_bits(kcs_bmc->map, LPC_HICR4,
+ LPC_HICR4_LADR12AS, LPC_HICR4_LADR12AS);
+ regmap_write(kcs_bmc->map, LPC_LADR12H, addr >> 8);
+ regmap_write(kcs_bmc->map, LPC_LADR12L, addr & 0xFF);
+ break;
+
+ case 3:
+ regmap_write(kcs_bmc->map, LPC_LADR3H, addr >> 8);
+ regmap_write(kcs_bmc->map, LPC_LADR3L, addr & 0xFF);
+ break;
+
+ case 4:
+ regmap_write(kcs_bmc->map, LPC_LADR4, ((addr + 1) << 16) |
+ addr);
+ break;
+
+ default:
+ break;
+ }
+}
+
+static void kcs_enable_channel(struct kcs_bmc *kcs_bmc, int enable)
+{
+ switch (kcs_bmc->chan) {
+ case 1:
+ if (enable) {
+ regmap_update_bits(kcs_bmc->map, LPC_HICR2,
+ LPC_HICR2_IBFIF1, LPC_HICR2_IBFIF1);
+ regmap_update_bits(kcs_bmc->map, LPC_HICR0,
+ LPC_HICR0_LPC1E, LPC_HICR0_LPC1E);
+ } else {
+ regmap_update_bits(kcs_bmc->map, LPC_HICR0,
+ LPC_HICR0_LPC1E, 0);
+ regmap_update_bits(kcs_bmc->map, LPC_HICR2,
+ LPC_HICR2_IBFIF1, 0);
+ }
+ break;
+
+ case 2:
+ if (enable) {
+ regmap_update_bits(kcs_bmc->map, LPC_HICR2,
+ LPC_HICR2_IBFIF2, LPC_HICR2_IBFIF2);
+ regmap_update_bits(kcs_bmc->map, LPC_HICR0,
+ LPC_HICR0_LPC2E, LPC_HICR0_LPC2E);
+ } else {
+ regmap_update_bits(kcs_bmc->map, LPC_HICR0,
+ LPC_HICR0_LPC2E, 0);
+ regmap_update_bits(kcs_bmc->map, LPC_HICR2,
+ LPC_HICR2_IBFIF2, 0);
+ }
+ break;
+
+ case 3:
+ if (enable) {
+ regmap_update_bits(kcs_bmc->map, LPC_HICR2,
+ LPC_HICR2_IBFIF3, LPC_HICR2_IBFIF3);
+ regmap_update_bits(kcs_bmc->map, LPC_HICR0,
+ LPC_HICR0_LPC3E, LPC_HICR0_LPC3E);
+ regmap_update_bits(kcs_bmc->map, LPC_HICR4,
+ LPC_HICR4_KCSENBL, LPC_HICR4_KCSENBL);
+ } else {
+ regmap_update_bits(kcs_bmc->map, LPC_HICR0,
+ LPC_HICR0_LPC3E, 0);
+ regmap_update_bits(kcs_bmc->map, LPC_HICR4,
+ LPC_HICR4_KCSENBL, 0);
+ regmap_update_bits(kcs_bmc->map, LPC_HICR2,
+ LPC_HICR2_IBFIF3, 0);
+ }
+ break;
+
+ case 4:
+ if (enable) {
+ regmap_update_bits(kcs_bmc->map, LPC_HICRB,
+ LPC_HICRB_IBFIF4 | LPC_HICRB_LPC4E,
+ LPC_HICRB_IBFIF4 | LPC_HICRB_LPC4E);
+ } else {
+ regmap_update_bits(kcs_bmc->map, LPC_HICRB,
+ LPC_HICRB_IBFIF4 | LPC_HICRB_LPC4E,
+ 0);
+ }
+ break;
+
+ default:
+ break;
+ }
+}
+
+static void kcs_rx_data(struct kcs_bmc *kcs_bmc)
+{
+ u8 data;
+
+ switch (kcs_bmc->kcs_phase) {
+ case KCS_PHASE_WRITE:
+ kcs_set_state(kcs_bmc, KCS_WRITE_STATE);
+
+ /* set OBF before reading data */
+ kcs_outb(kcs_bmc, KCS_ZERO_DATA, kcs_bmc->odr);
+
+ if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ)
+ kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
+ kcs_inb(kcs_bmc, kcs_bmc->idr);
+ break;
+
+ case KCS_PHASE_WRITE_END:
+ kcs_set_state(kcs_bmc, KCS_READ_STATE);
+
+ if (kcs_bmc->data_in_idx < KCS_MSG_BUFSIZ)
+ kcs_bmc->data_in[kcs_bmc->data_in_idx++] =
+ kcs_inb(kcs_bmc, kcs_bmc->idr);
+
+ kcs_bmc->kcs_phase = KCS_PHASE_READ;
+ if (kcs_bmc->running) {
+ kcs_bmc->data_in_avail = 1;
+ wake_up_interruptible(&kcs_bmc->queue);
+ }
+ break;
+
+ case KCS_PHASE_READ:
+ if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len)
+ kcs_set_state(kcs_bmc, KCS_IDLE_STATE);
+
+ data = kcs_inb(kcs_bmc, kcs_bmc->idr);
+ if (data != KCS_READ_BYTE) {
+ kcs_set_state(kcs_bmc, KCS_ERROR_STATE);
+ kcs_outb(kcs_bmc, KCS_ZERO_DATA, kcs_bmc->odr);
+ break;
+ }
+
+ if (kcs_bmc->data_out_idx == kcs_bmc->data_out_len) {
+ kcs_outb(kcs_bmc, KCS_ZERO_DATA, kcs_bmc->odr);
+ kcs_bmc->kcs_phase = KCS_PHASE_IDLE;
+ break;
+ }
+
+ kcs_outb(kcs_bmc, kcs_bmc->data_out[kcs_bmc->data_out_idx++],
+ kcs_bmc->odr);
+ break;
+
+ case KCS_PHASE_ABORT:
+ switch (kcs_bmc->abort_phase) {
+ case ABORT_PHASE_ERROR1:
+ kcs_set_state(kcs_bmc, KCS_READ_STATE);
+
+ /* Read the Dummy byte */
+ kcs_inb(kcs_bmc, kcs_bmc->idr);
+
+ kcs_outb(kcs_bmc, kcs_bmc->kcs_error, kcs_bmc->odr);
+ kcs_bmc->abort_phase = ABORT_PHASE_ERROR2;
+ break;
+
+ case ABORT_PHASE_ERROR2:
+ kcs_set_state(kcs_bmc, KCS_IDLE_STATE);
+
+ /* Read the Dummy byte */
+ kcs_inb(kcs_bmc, kcs_bmc->idr);
+
+ kcs_outb(kcs_bmc, KCS_ZERO_DATA, kcs_bmc->odr);
+ kcs_bmc->kcs_phase = KCS_PHASE_IDLE;
+ kcs_bmc->abort_phase = 0;
+ break;
+
+ default:
+ break;
+ }
+
+ break;
+
+ case KCS_PHASE_ERROR:
+ kcs_set_state(kcs_bmc, KCS_ERROR_STATE);
+
+ /* Read the Dummy byte */
+ kcs_inb(kcs_bmc, kcs_bmc->idr);
+
+ kcs_outb(kcs_bmc, KCS_ZERO_DATA, kcs_bmc->odr);
+ break;
+
+ default:
+ kcs_set_state(kcs_bmc, KCS_ERROR_STATE);
+
+ /* Read the Dummy byte */
+ kcs_inb(kcs_bmc, kcs_bmc->idr);
+
+ kcs_outb(kcs_bmc, KCS_ZERO_DATA, kcs_bmc->odr);
+ break;
+ }
+}
+
+static void kcs_rx_cmd(struct kcs_bmc *kcs_bmc)
+{
+ u8 cmd;
+
+ kcs_set_state(kcs_bmc, KCS_WRITE_STATE);
+
+ /* Dummy data to generate OBF */
+ kcs_outb(kcs_bmc, KCS_ZERO_DATA, kcs_bmc->odr);
+
+ cmd = kcs_inb(kcs_bmc, kcs_bmc->idr);
+ switch (cmd) {
+ case KCS_WRITE_START:
+ kcs_bmc->data_in_avail = 0;
+ kcs_bmc->data_in_idx = 0;
+ kcs_bmc->kcs_phase = KCS_PHASE_WRITE;
+ kcs_bmc->kcs_error = KCS_NO_ERROR;
+ break;
+
+ case KCS_WRITE_END:
+ kcs_bmc->kcs_phase = KCS_PHASE_WRITE_END;
+ break;
+
+ case KCS_ABORT:
+ if (kcs_bmc->kcs_error == KCS_NO_ERROR)
+ kcs_bmc->kcs_error = KCS_ABORTED_BY_COMMAND;
+
+ kcs_bmc->kcs_phase = KCS_PHASE_ABORT;
+ kcs_bmc->abort_phase = ABORT_PHASE_ERROR1;
+ break;
+
+ default:
+ kcs_bmc->kcs_error = KCS_ILLEGAL_CONTROL_CODE;
+ kcs_set_state(kcs_bmc, KCS_ERROR_STATE);
+ kcs_outb(kcs_bmc, kcs_bmc->kcs_error, kcs_bmc->odr);
+ kcs_bmc->kcs_phase = KCS_PHASE_ERROR;
+ break;
+ }
+}
+
+/*
+ * Whenever the BMC is reset (from power-on or a hard reset), the State Bits
+ * are initialized to "11 - Error State". Doing so allows SMS to detect that
+ * the BMC has been reset and that any message in process has been terminated
+ * by the BMC.
+ */
+static void kcs_force_abort(struct kcs_bmc *kcs_bmc)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&kcs_bmc->lock, flags);
+ kcs_set_state(kcs_bmc, KCS_ERROR_STATE);
+
+ /* Read the Dummy byte */
+ kcs_inb(kcs_bmc, kcs_bmc->idr);
+
+ kcs_outb(kcs_bmc, KCS_ZERO_DATA, kcs_bmc->odr);
+ kcs_bmc->kcs_phase = KCS_PHASE_ERROR;
+ spin_unlock_irqrestore(&kcs_bmc->lock, flags);
+}
+
+static irqreturn_t kcs_bmc_irq(int irq, void *arg)
+{
+ struct kcs_bmc *kcs_bmc = arg;
+ u32 sts;
+
+ if (regmap_read(kcs_bmc->map, kcs_bmc->str, &sts) != 0)
+ return IRQ_NONE;
+
+ sts &= (KCS_STR_IBF | KCS_STR_CMD_DAT);
+
+ switch (sts) {
+ case KCS_STR_IBF | KCS_STR_CMD_DAT:
+ kcs_rx_cmd(kcs_bmc);
+ break;
+
+ case KCS_STR_IBF:
+ kcs_rx_data(kcs_bmc);
+
+ default:
+ return IRQ_NONE;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int kcs_bmc_config_irq(struct kcs_bmc *kcs_bmc,
+ struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ int irq;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ return devm_request_irq(dev, irq, kcs_bmc_irq, IRQF_SHARED,
+ dev_name(dev), kcs_bmc);
+}
+
+
+static inline struct kcs_bmc *file_kcs_bmc(struct file *filp)
+{
+ return container_of(filp->private_data, struct kcs_bmc, miscdev);
+}
+
+static int kcs_bmc_open(struct inode *inode, struct file *filp)
+{
+ struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
+ unsigned long flags;
+
+ if (kcs_bmc->running)
+ return -EBUSY;
+
+ spin_lock_irqsave(&kcs_bmc->lock, flags);
+ kcs_bmc->kcs_phase = KCS_PHASE_IDLE;
+ kcs_bmc->running = 1;
+ kcs_bmc->data_in_avail = 0;
+ spin_unlock_irqrestore(&kcs_bmc->lock, flags);
+
+ return 0;
+}
+
+static unsigned int kcs_bmc_poll(struct file *filp, poll_table *wait)
+{
+ struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
+ unsigned int mask = 0;
+
+ poll_wait(filp, &kcs_bmc->queue, wait);
+
+ if (kcs_bmc->data_in_avail)
+ mask |= POLLIN;
+
+ if (kcs_bmc->kcs_phase == KCS_PHASE_READ)
+ mask |= POLLOUT;
+
+ return mask;
+}
+
+static ssize_t kcs_bmc_read(struct file *filp, char *buf,
+ size_t count, loff_t *offset)
+{
+ struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
+ int rv;
+
+ rv = wait_event_interruptible(kcs_bmc->queue,
+ kcs_bmc->data_in_avail != 0);
+ if (rv < 0)
+ return -ERESTARTSYS;
+
+ kcs_bmc->data_in_avail = 0;
+
+ if (count > kcs_bmc->data_in_idx)
+ count = kcs_bmc->data_in_idx;
+
+ if (copy_to_user(buf, kcs_bmc->data_in, count))
+ return -EFAULT;
+
+ return count;
+}
+
+static ssize_t kcs_bmc_write(struct file *filp, const char *buf,
+ size_t count, loff_t *offset)
+{
+ struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
+ unsigned long flags;
+
+ if (count < 1 || count > KCS_MSG_BUFSIZ)
+ return -EINVAL;
+
+ if (copy_from_user(kcs_bmc->data_out, buf, count))
+ return -EFAULT;
+
+ spin_lock_irqsave(&kcs_bmc->lock, flags);
+ if (kcs_bmc->kcs_phase == KCS_PHASE_READ) {
+ kcs_bmc->data_out_idx = 1;
+ kcs_bmc->data_out_len = count;
+ kcs_outb(kcs_bmc, kcs_bmc->data_out[0], kcs_bmc->odr);
+ }
+ spin_unlock_irqrestore(&kcs_bmc->lock, flags);
+
+ return count;
+}
+
+static long kcs_bmc_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
+ long ret = 0;
+
+ switch (cmd) {
+ case KCS_BMC_IOCTL_SET_ATN:
+ kcs_set_atn(kcs_bmc);
+ break;
+
+ case KCS_BMC_IOCTL_CLR_ATN:
+ kcs_clear_atn(kcs_bmc);
+ break;
+
+ case KCS_BMC_IOCTL_FORCE_ABORT:
+ kcs_force_abort(kcs_bmc);
+ break;
+
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+ return ret;
+}
+
+static int kcs_bmc_release(struct inode *inode, struct file *filp)
+{
+ struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
+ unsigned long flags;
+
+ spin_lock_irqsave(&kcs_bmc->lock, flags);
+ kcs_bmc->running = 0;
+ spin_unlock_irqrestore(&kcs_bmc->lock, flags);
+
+ return 0;
+}
+
+static const struct file_operations kcs_bmc_fops = {
+ .owner = THIS_MODULE,
+ .open = kcs_bmc_open,
+ .read = kcs_bmc_read,
+ .write = kcs_bmc_write,
+ .release = kcs_bmc_release,
+ .poll = kcs_bmc_poll,
+ .unlocked_ioctl = kcs_bmc_ioctl,
+};
+
+static int kcs_bmc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct kcs_ioreg *ioreg;
+ struct kcs_bmc *kcs_bmc;
+ u32 chan, addr;
+ int rc;
+
+ kcs_bmc = devm_kzalloc(dev, sizeof(*kcs_bmc), GFP_KERNEL);
+ if (!kcs_bmc)
+ return -ENOMEM;
+
+ rc = of_property_read_u32(dev->of_node, "kcs_chan", &chan);
+ if ((rc != 0) || (chan == 0 || chan > KCS_CHANNEL_MAX)) {
+ dev_err(dev, "no valid 'kcs_chan' configured\n");
+ return -ENODEV;
+ }
+
+ rc = of_property_read_u32(dev->of_node, "kcs_addr", &addr);
+ if (rc) {
+ dev_err(dev, "no valid 'kcs_addr' configured\n");
+ return -ENODEV;
+ }
+
+ kcs_bmc->map = syscon_node_to_regmap(dev->parent->of_node);
+ if (IS_ERR(kcs_bmc->map)) {
+ dev_err(dev, "Couldn't get regmap\n");
+ return -ENODEV;
+ }
+
+ dev_set_name(dev, "ipmi-kcs%u", chan);
+
+ spin_lock_init(&kcs_bmc->lock);
+ kcs_bmc->chan = chan;
+
+ ioreg = &kcs_ioreg_map[chan - 1];
+ kcs_bmc->idr = ioreg->idr;
+ kcs_bmc->odr = ioreg->odr;
+ kcs_bmc->str = ioreg->str;
+
+ init_waitqueue_head(&kcs_bmc->queue);
+ kcs_bmc->data_in = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+ kcs_bmc->data_out = devm_kmalloc(dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
+ if (kcs_bmc->data_in == NULL || kcs_bmc->data_out == NULL) {
+ dev_err(dev, "Failed to allocate data buffers\n");
+ return -ENOMEM;
+ }
+
+ kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
+ kcs_bmc->miscdev.name = dev_name(dev);
+ kcs_bmc->miscdev.fops = &kcs_bmc_fops;
+ rc = misc_register(&kcs_bmc->miscdev);
+ if (rc) {
+ dev_err(dev, "Unable to register device\n");
+ return rc;
+ }
+
+ kcs_set_addr(kcs_bmc, addr);
+ kcs_enable_channel(kcs_bmc, 1);
+
+ rc = kcs_bmc_config_irq(kcs_bmc, pdev);
+ if (rc) {
+ misc_deregister(&kcs_bmc->miscdev);
+ return rc;
+ }
+
+ dev_set_drvdata(&pdev->dev, kcs_bmc);
+
+ dev_info(dev, "addr=0x%x, idr=0x%x, odr=0x%x, str=0x%x\n",
+ addr, kcs_bmc->idr, kcs_bmc->odr, kcs_bmc->str);
+
+ return 0;
+}
+
+static int kcs_bmc_remove(struct platform_device *pdev)
+{
+ struct kcs_bmc *kcs_bmc = dev_get_drvdata(&pdev->dev);
+
+ misc_deregister(&kcs_bmc->miscdev);
+
+ return 0;
+}
+
+static const struct of_device_id kcs_bmc_match[] = {
+ { .compatible = "aspeed,ast2400-kcs-bmc" },
+ { .compatible = "aspeed,ast2500-kcs-bmc" },
+ { }
+};
+
+static struct platform_driver kcs_bmc_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = kcs_bmc_match,
+ },
+ .probe = kcs_bmc_probe,
+ .remove = kcs_bmc_remove,
+};
+
+module_platform_driver(kcs_bmc_driver);
+
+MODULE_DEVICE_TABLE(of, kcs_bmc_match);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Haiyue Wang <haiyue.w...@linux.intel.com>");
+MODULE_DESCRIPTION("Linux device interface to the IPMI KCS interface");
diff --git a/include/uapi/linux/kcs-bmc.h b/include/uapi/linux/kcs-bmc.h
new file mode 100644
index 0000000..d1550d3
--- /dev/null
+++ b/include/uapi/linux/kcs-bmc.h
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2015-2018, Intel Corporation.
+
+#ifndef _UAPI_LINUX_KCS_BMC_H
+#define _UAPI_LINUX_KCS_BMC_H
+
+#include <linux/ioctl.h>
+
+#define __KCS_BMC_IOCTL_MAGIC 'K'
+#define KCS_BMC_IOCTL_SET_ATN _IO(__KCS_BMC_IOCTL_MAGIC, 1)
+#define KCS_BMC_IOCTL_CLR_ATN _IO(__KCS_BMC_IOCTL_MAGIC, 2)
+#define KCS_BMC_IOCTL_FORCE_ABORT _IO(__KCS_BMC_IOCTL_MAGIC, 3)
+
+#endif /* _UAPI_LINUX_KCS_BMC_H */
--
2.7.4
