RE: [PATCH linux ipmi for BMC] ipmi: add an Aspeed KCS IPMI BMC driver
From: Haiyue Wang
Date: Thu Dec 14 2017 - 22:07:26 EST
Thanks Corey, yes, I ran through checkpatch. Fix most of warnings and errors. I thought 2 and 3 would be acceptable,
will fix it in new patch,and together with fix for comments from all of you. And how to fix item 1 ?
1. WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
#115:
new file mode 100644
2. WARNING: Prefer using '"%s...", __func__' to using 'kcs_inb', this function's name, in a string
#289: FILE: drivers/char/ipmi/kcs-bmc.c:170:
+ WARN(rc != 0, "kcs_inb failed: %d\n", rc);
3. WARNING: Prefer using '"%s...", __func__' to using 'kcs_outb', this function's name, in a string
#299: FILE: drivers/char/ipmi/kcs-bmc.c:180:
+ WARN(rc != 0, "kcs_outb failed: %d\n", rc);
total: 0 errors, 3 warnings, 836 lines checked
-----Original Message-----
From: Corey Minyard [mailto:tcminyard@xxxxxxxxx] On Behalf Of Corey Minyard
Sent: Friday, December 15, 2017 10:31
To: Haiyue Wang <haiyue.wang@xxxxxxxxxxxxxxx>; openipmi-developer@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; CÃdric Le Goater <clg@xxxxxxxx>; Jeremy Kerr <jk@xxxxxxxxxx>; Joel Stanley <joel@xxxxxxxxx>; Andrew Jeffery <andrew@xxxxxxxx>
Subject: Re: [PATCH linux ipmi for BMC] ipmi: add an Aspeed KCS IPMI BMC driver
On 12/14/2017 08:03 PM, Haiyue Wang wrote:
> [based torvalds/linux.git]
>
> This patch adds a simple device driver to expose the KCS interface on
> Aspeed SOCs (AST2400 and AST2500) as a character device. Such SOCs are
> commonly used as BMCs (BaseBoard Management Controllers) and this
> driver implements the BMC side of the KCS interface.
>
> The KCS (Keyboard Controller Style) interface is used to perform
> in-band IPMI communication between a host and its BMC.
>
> The device name defaults to '/dev/ipmi-kcsX', X=1,2,3,4.
Did you run this through checkpatch? I saw a few things.
I was hoping to see some of the openbmc people comment on this.
-corey
> Signed-off-by: Haiyue Wang <haiyue.wang@xxxxxxxxxxxxxxx>
> ---
> .../devicetree/bindings/mfd/aspeed-lpc.txt | 31 +-
> drivers/char/ipmi/Kconfig | 9 +
> drivers/char/ipmi/Makefile | 1 +
> drivers/char/ipmi/kcs-bmc.c | 759 +++++++++++++++++++++
> include/uapi/linux/kcs-bmc.h | 13 +
> 5 files changed, 810 insertions(+), 3 deletions(-)
> create mode 100644 drivers/char/ipmi/kcs-bmc.c
> create mode 100644 include/uapi/linux/kcs-bmc.h
>
> diff --git a/Documentation/devicetree/bindings/mfd/aspeed-lpc.txt
> b/Documentation/devicetree/bindings/mfd/aspeed-lpc.txt
> index 514d82c..e682000 100644
> --- a/Documentation/devicetree/bindings/mfd/aspeed-lpc.txt
> +++ b/Documentation/devicetree/bindings/mfd/aspeed-lpc.txt
> @@ -62,12 +62,24 @@ BMC Node
> --------
>
> - compatible: One of:
> - "aspeed,ast2400-lpc-bmc"
> - "aspeed,ast2500-lpc-bmc"
> + "aspeed,ast2400-lpc-bmc", "simple-mfd", "syscon"
> + "aspeed,ast2500-lpc-bmc", "simple-mfd", "syscon"
>
> - reg: contains the physical address and length values of the
> H8S/2168-compatible LPC controller memory region
>
> +BMC KCS Node
> +------------
> +
> +- compatible: One of:
> + "aspeed,ast2400-kcs-bmc"
> + "aspeed,ast2500-kcs-bmc"
> +
> +- kcs_chan: The LPC channel number
> +
> +- kcs_addr: The host CPU IO map address
> +
> +
> Host Node
> ---------
>
> @@ -94,8 +106,21 @@ lpc: lpc@1e789000 {
> ranges = <0x0 0x1e789000 0x1000>;
>
> lpc_bmc: lpc-bmc@0 {
> - compatible = "aspeed,ast2500-lpc-bmc";
> + compatible = "aspeed,ast2500-lpc-bmc", "simple-mfd", "syscon";
> reg = <0x0 0x80>;
> + reg-io-width = <4>;
> +
> + #address-cells = <1>;
> + #size-cells = <1>;
> + ranges = <0x0 0x0 0x80>;
> +
> + kcs3: kcs3@0 {
> + compatible = "aspeed,ast2500-kcs-bmc";
> + interrupts = <8>;
> + kcs_chan = <3>;
> + kcs_addr = <0xCA2>;
> + status = "okay";
> + };
> };
>
> lpc_host: lpc-host@80 {
> diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
> index 3544abc..3a9d29b 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
> + depends on REGMAP && REGMAP_MMIO && MFD_SYSCON
> + 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..bcbd2d6
> --- /dev/null
> +++ b/drivers/char/ipmi/kcs-bmc.c
> @@ -0,0 +1,759 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2015-2017, Intel Corporation.
> +
> +#include <linux/atomic.h>
> +#include <linux/slab.h>
> +#include <linux/kcs-bmc.h>
> +#include <linux/errno.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.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/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_ATN BIT(2)
> +#define KCS_STR_IBF BIT(1)
> +#define KCS_STR_OBF BIT(0)
> +
> +
> +/***************************** LPC Register
> +****************************/
> +/* 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_channel_ioregs[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;
> + int irq;
> + 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;
> + char name[16];
> +};
> +
> +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, "kcs_inb 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, "kcs_outb failed: %d\n", rc); }
> +
> +static void kcs_set_state(struct kcs_bmc *kcs_bmc, u8 state) {
> + int rc;
> +
> + rc = regmap_update_bits(kcs_bmc->map, kcs_bmc->str,
> + KCS_STR_STATE_MASK,
> + KCS_STR_STATE(state));
> + WARN(rc != 0, "KCS_STR_STATE failed: %d\n", rc); }
> +
> +static void kcs_set_atn(struct kcs_bmc *kcs_bmc, unsigned long set) {
> + int rc;
> +
> + rc = regmap_update_bits(kcs_bmc->map, kcs_bmc->str,
> + KCS_STR_ATN,
> + set != 0 ? KCS_STR_ATN : 0);
> + WARN(rc != 0, "KCS_STR_ATN failed: %d\n", rc); }
> +
> +/********************************************************************
> +*
> + * 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
> +
> +*********************************************************************
> +/ 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) {
> + int rc;
> + u32 sts;
> + struct kcs_bmc *kcs_bmc = arg;
> +
> + rc = regmap_read(kcs_bmc->map, kcs_bmc->str, &sts);
> + if (rc)
> + 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 rc;
> +
> + kcs_bmc->irq = platform_get_irq(pdev, 0);
> + if (!kcs_bmc->irq)
> + return -ENODEV;
> +
> + rc = devm_request_irq(dev, kcs_bmc->irq, kcs_bmc_irq, IRQF_SHARED,
> + kcs_bmc->name, kcs_bmc);
> + if (rc < 0) {
> + dev_warn(dev, "Unable to request IRQ %d\n", kcs_bmc->irq);
> + kcs_bmc->irq = 0;
> + return rc;
> + }
> +
> + return rc;
> +}
> +
> +
> +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) {
> + unsigned long flags;
> + struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
> +
> + 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)
> +{
> + unsigned int mask = 0;
> + struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
> +
> + 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)
> +{
> + int rv;
> + struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
> +
> + 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) {
> + unsigned long flags;
> + struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
> +
> + 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)
> +{
> + long ret = 0;
> + struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
> +
> + switch (cmd) {
> + case KCS_BMC_IOCTL_SMS_ATN:
> + kcs_set_atn(kcs_bmc, arg);
> + 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) {
> + unsigned long flags;
> + struct kcs_bmc *kcs_bmc = file_kcs_bmc(filp);
> +
> + 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 kcs_bmc *kcs_bmc;
> + struct device *dev;
> + const struct kcs_ioreg *ioreg;
> + u32 chan, addr;
> + int rc;
> +
> + dev = &pdev->dev;
> +
> + 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;
> + }
> +
> + spin_lock_init(&kcs_bmc->lock);
> + kcs_bmc->chan = chan;
> +
> + ioreg = &kcs_channel_ioregs[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;
> + }
> +
> + snprintf(kcs_bmc->name, sizeof(kcs_bmc->name), "ipmi-kcs%u", chan);
> + kcs_bmc->miscdev.minor = MISC_DYNAMIC_MINOR;
> + kcs_bmc->miscdev.name = kcs_bmc->name;
> + 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) {
> + dev_err(dev, "Failed to configure IRQ\n");
> + 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");
> +MODULE_AUTHOR("Haiyue Wang <haiyue.wang@xxxxxxxxxxxxxxx>");
> +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..f0c3ff60
> --- /dev/null
> +++ b/include/uapi/linux/kcs-bmc.h
> @@ -0,0 +1,13 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2015-2017, 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_SMS_ATN _IOW(__KCS_BMC_IOCTL_MAGIC, 1, unsigned long)
> +#define KCS_BMC_IOCTL_FORCE_ABORT _IO(__KCS_BMC_IOCTL_MAGIC, 2)
> +
> +#endif /* _UAPI_LINUX_KCS_BMC_H */