cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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kcs_bmc_aspeed.c (17767B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Copyright (c) 2015-2018, Intel Corporation.
      4 */
      5
      6#define pr_fmt(fmt) "aspeed-kcs-bmc: " fmt
      7
      8#include <linux/atomic.h>
      9#include <linux/errno.h>
     10#include <linux/interrupt.h>
     11#include <linux/io.h>
     12#include <linux/irq.h>
     13#include <linux/mfd/syscon.h>
     14#include <linux/module.h>
     15#include <linux/of.h>
     16#include <linux/of_address.h>
     17#include <linux/of_device.h>
     18#include <linux/platform_device.h>
     19#include <linux/poll.h>
     20#include <linux/regmap.h>
     21#include <linux/sched.h>
     22#include <linux/slab.h>
     23#include <linux/timer.h>
     24
     25#include "kcs_bmc_device.h"
     26
     27
     28#define DEVICE_NAME     "ast-kcs-bmc"
     29
     30#define KCS_CHANNEL_MAX     4
     31
     32/*
     33 * Field class descriptions
     34 *
     35 * LPCyE	Enable LPC channel y
     36 * IBFIEy	Input Buffer Full IRQ Enable for LPC channel y
     37 * IRQxEy	Assert SerIRQ x for LPC channel y (Deprecated, use IDyIRQX, IRQXEy)
     38 * IDyIRQX	Use the specified 4-bit SerIRQ for LPC channel y
     39 * SELyIRQX	SerIRQ polarity for LPC channel y (low: 0, high: 1)
     40 * IRQXEy	Assert the SerIRQ specified in IDyIRQX for LPC channel y
     41 */
     42
     43#define LPC_TYIRQX_LOW       0b00
     44#define LPC_TYIRQX_HIGH      0b01
     45#define LPC_TYIRQX_RSVD      0b10
     46#define LPC_TYIRQX_RISING    0b11
     47
     48#define LPC_HICR0            0x000
     49#define     LPC_HICR0_LPC3E          BIT(7)
     50#define     LPC_HICR0_LPC2E          BIT(6)
     51#define     LPC_HICR0_LPC1E          BIT(5)
     52#define LPC_HICR2            0x008
     53#define     LPC_HICR2_IBFIE3         BIT(3)
     54#define     LPC_HICR2_IBFIE2         BIT(2)
     55#define     LPC_HICR2_IBFIE1         BIT(1)
     56#define LPC_HICR4            0x010
     57#define     LPC_HICR4_LADR12AS       BIT(7)
     58#define     LPC_HICR4_KCSENBL        BIT(2)
     59#define LPC_SIRQCR0	     0x070
     60/* IRQ{12,1}E1 are deprecated as of AST2600 A3 but necessary for prior chips */
     61#define     LPC_SIRQCR0_IRQ12E1	     BIT(1)
     62#define     LPC_SIRQCR0_IRQ1E1	     BIT(0)
     63#define LPC_HICR5	     0x080
     64#define     LPC_HICR5_ID3IRQX_MASK   GENMASK(23, 20)
     65#define     LPC_HICR5_ID3IRQX_SHIFT  20
     66#define     LPC_HICR5_ID2IRQX_MASK   GENMASK(19, 16)
     67#define     LPC_HICR5_ID2IRQX_SHIFT  16
     68#define     LPC_HICR5_SEL3IRQX       BIT(15)
     69#define     LPC_HICR5_IRQXE3         BIT(14)
     70#define     LPC_HICR5_SEL2IRQX       BIT(13)
     71#define     LPC_HICR5_IRQXE2         BIT(12)
     72#define LPC_LADR3H           0x014
     73#define LPC_LADR3L           0x018
     74#define LPC_LADR12H          0x01C
     75#define LPC_LADR12L          0x020
     76#define LPC_IDR1             0x024
     77#define LPC_IDR2             0x028
     78#define LPC_IDR3             0x02C
     79#define LPC_ODR1             0x030
     80#define LPC_ODR2             0x034
     81#define LPC_ODR3             0x038
     82#define LPC_STR1             0x03C
     83#define LPC_STR2             0x040
     84#define LPC_STR3             0x044
     85#define LPC_HICRB            0x100
     86#define     LPC_HICRB_EN16LADR2      BIT(5)
     87#define     LPC_HICRB_EN16LADR1      BIT(4)
     88#define     LPC_HICRB_IBFIE4         BIT(1)
     89#define     LPC_HICRB_LPC4E          BIT(0)
     90#define LPC_HICRC            0x104
     91#define     LPC_HICRC_ID4IRQX_MASK   GENMASK(7, 4)
     92#define     LPC_HICRC_ID4IRQX_SHIFT  4
     93#define     LPC_HICRC_TY4IRQX_MASK   GENMASK(3, 2)
     94#define     LPC_HICRC_TY4IRQX_SHIFT  2
     95#define     LPC_HICRC_OBF4_AUTO_CLR  BIT(1)
     96#define     LPC_HICRC_IRQXE4         BIT(0)
     97#define LPC_LADR4            0x110
     98#define LPC_IDR4             0x114
     99#define LPC_ODR4             0x118
    100#define LPC_STR4             0x11C
    101#define LPC_LSADR12	     0x120
    102#define     LPC_LSADR12_LSADR2_MASK  GENMASK(31, 16)
    103#define     LPC_LSADR12_LSADR2_SHIFT 16
    104#define     LPC_LSADR12_LSADR1_MASK  GENMASK(15, 0)
    105#define     LPC_LSADR12_LSADR1_SHIFT 0
    106
    107#define OBE_POLL_PERIOD	     (HZ / 2)
    108
    109enum aspeed_kcs_irq_mode {
    110	aspeed_kcs_irq_none,
    111	aspeed_kcs_irq_serirq,
    112};
    113
    114struct aspeed_kcs_bmc {
    115	struct kcs_bmc_device kcs_bmc;
    116
    117	struct regmap *map;
    118
    119	struct {
    120		enum aspeed_kcs_irq_mode mode;
    121		int id;
    122	} upstream_irq;
    123
    124	struct {
    125		spinlock_t lock;
    126		bool remove;
    127		struct timer_list timer;
    128	} obe;
    129};
    130
    131static inline struct aspeed_kcs_bmc *to_aspeed_kcs_bmc(struct kcs_bmc_device *kcs_bmc)
    132{
    133	return container_of(kcs_bmc, struct aspeed_kcs_bmc, kcs_bmc);
    134}
    135
    136static u8 aspeed_kcs_inb(struct kcs_bmc_device *kcs_bmc, u32 reg)
    137{
    138	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
    139	u32 val = 0;
    140	int rc;
    141
    142	rc = regmap_read(priv->map, reg, &val);
    143	WARN(rc != 0, "regmap_read() failed: %d\n", rc);
    144
    145	return rc == 0 ? (u8) val : 0;
    146}
    147
    148static void aspeed_kcs_outb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 data)
    149{
    150	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
    151	int rc;
    152
    153	rc = regmap_write(priv->map, reg, data);
    154	WARN(rc != 0, "regmap_write() failed: %d\n", rc);
    155
    156	/* Trigger the upstream IRQ on ODR writes, if enabled */
    157
    158	switch (reg) {
    159	case LPC_ODR1:
    160	case LPC_ODR2:
    161	case LPC_ODR3:
    162	case LPC_ODR4:
    163		break;
    164	default:
    165		return;
    166	}
    167
    168	if (priv->upstream_irq.mode != aspeed_kcs_irq_serirq)
    169		return;
    170
    171	switch (kcs_bmc->channel) {
    172	case 1:
    173		switch (priv->upstream_irq.id) {
    174		case 12:
    175			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ12E1,
    176					   LPC_SIRQCR0_IRQ12E1);
    177			break;
    178		case 1:
    179			regmap_update_bits(priv->map, LPC_SIRQCR0, LPC_SIRQCR0_IRQ1E1,
    180					   LPC_SIRQCR0_IRQ1E1);
    181			break;
    182		default:
    183			break;
    184		}
    185		break;
    186	case 2:
    187		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE2, LPC_HICR5_IRQXE2);
    188		break;
    189	case 3:
    190		regmap_update_bits(priv->map, LPC_HICR5, LPC_HICR5_IRQXE3, LPC_HICR5_IRQXE3);
    191		break;
    192	case 4:
    193		regmap_update_bits(priv->map, LPC_HICRC, LPC_HICRC_IRQXE4, LPC_HICRC_IRQXE4);
    194		break;
    195	default:
    196		break;
    197	}
    198}
    199
    200static void aspeed_kcs_updateb(struct kcs_bmc_device *kcs_bmc, u32 reg, u8 mask, u8 val)
    201{
    202	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
    203	int rc;
    204
    205	rc = regmap_update_bits(priv->map, reg, mask, val);
    206	WARN(rc != 0, "regmap_update_bits() failed: %d\n", rc);
    207}
    208
    209/*
    210 * AST_usrGuide_KCS.pdf
    211 * 2. Background:
    212 *   we note D for Data, and C for Cmd/Status, default rules are
    213 *     A. KCS1 / KCS2 ( D / C:X / X+4 )
    214 *        D / C : CA0h / CA4h
    215 *        D / C : CA8h / CACh
    216 *     B. KCS3 ( D / C:XX2h / XX3h )
    217 *        D / C : CA2h / CA3h
    218 *        D / C : CB2h / CB3h
    219 *     C. KCS4
    220 *        D / C : CA4h / CA5h
    221 */
    222static int aspeed_kcs_set_address(struct kcs_bmc_device *kcs_bmc, u32 addrs[2], int nr_addrs)
    223{
    224	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
    225
    226	if (WARN_ON(nr_addrs < 1 || nr_addrs > 2))
    227		return -EINVAL;
    228
    229	switch (priv->kcs_bmc.channel) {
    230	case 1:
    231		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, 0);
    232		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
    233		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
    234		if (nr_addrs == 2) {
    235			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR1_MASK,
    236					   addrs[1] << LPC_LSADR12_LSADR1_SHIFT);
    237
    238			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR1,
    239					   LPC_HICRB_EN16LADR1);
    240		}
    241		break;
    242
    243	case 2:
    244		regmap_update_bits(priv->map, LPC_HICR4, LPC_HICR4_LADR12AS, LPC_HICR4_LADR12AS);
    245		regmap_write(priv->map, LPC_LADR12H, addrs[0] >> 8);
    246		regmap_write(priv->map, LPC_LADR12L, addrs[0] & 0xFF);
    247		if (nr_addrs == 2) {
    248			regmap_update_bits(priv->map, LPC_LSADR12, LPC_LSADR12_LSADR2_MASK,
    249					   addrs[1] << LPC_LSADR12_LSADR2_SHIFT);
    250
    251			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_EN16LADR2,
    252					   LPC_HICRB_EN16LADR2);
    253		}
    254		break;
    255
    256	case 3:
    257		if (nr_addrs == 2) {
    258			dev_err(priv->kcs_bmc.dev,
    259				"Channel 3 only supports inferred status IO address\n");
    260			return -EINVAL;
    261		}
    262
    263		regmap_write(priv->map, LPC_LADR3H, addrs[0] >> 8);
    264		regmap_write(priv->map, LPC_LADR3L, addrs[0] & 0xFF);
    265		break;
    266
    267	case 4:
    268		if (nr_addrs == 1)
    269			regmap_write(priv->map, LPC_LADR4, ((addrs[0] + 1) << 16) | addrs[0]);
    270		else
    271			regmap_write(priv->map, LPC_LADR4, (addrs[1] << 16) | addrs[0]);
    272
    273		break;
    274
    275	default:
    276		return -EINVAL;
    277	}
    278
    279	return 0;
    280}
    281
    282static inline int aspeed_kcs_map_serirq_type(u32 dt_type)
    283{
    284	switch (dt_type) {
    285	case IRQ_TYPE_EDGE_RISING:
    286		return LPC_TYIRQX_RISING;
    287	case IRQ_TYPE_LEVEL_HIGH:
    288		return LPC_TYIRQX_HIGH;
    289	case IRQ_TYPE_LEVEL_LOW:
    290		return LPC_TYIRQX_LOW;
    291	default:
    292		return -EINVAL;
    293	}
    294}
    295
    296static int aspeed_kcs_config_upstream_irq(struct aspeed_kcs_bmc *priv, u32 id, u32 dt_type)
    297{
    298	unsigned int mask, val, hw_type;
    299	int ret;
    300
    301	if (id > 15)
    302		return -EINVAL;
    303
    304	ret = aspeed_kcs_map_serirq_type(dt_type);
    305	if (ret < 0)
    306		return ret;
    307	hw_type = ret;
    308
    309	priv->upstream_irq.mode = aspeed_kcs_irq_serirq;
    310	priv->upstream_irq.id = id;
    311
    312	switch (priv->kcs_bmc.channel) {
    313	case 1:
    314		/* Needs IRQxE1 rather than (ID1IRQX, SEL1IRQX, IRQXE1) before AST2600 A3 */
    315		break;
    316	case 2:
    317		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
    318			return -EINVAL;
    319
    320		mask = LPC_HICR5_SEL2IRQX | LPC_HICR5_ID2IRQX_MASK;
    321		val = (id << LPC_HICR5_ID2IRQX_SHIFT);
    322		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL2IRQX : 0;
    323		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
    324
    325		break;
    326	case 3:
    327		if (!(hw_type == LPC_TYIRQX_LOW || hw_type == LPC_TYIRQX_HIGH))
    328			return -EINVAL;
    329
    330		mask = LPC_HICR5_SEL3IRQX | LPC_HICR5_ID3IRQX_MASK;
    331		val = (id << LPC_HICR5_ID3IRQX_SHIFT);
    332		val |= (hw_type == LPC_TYIRQX_HIGH) ? LPC_HICR5_SEL3IRQX : 0;
    333		regmap_update_bits(priv->map, LPC_HICR5, mask, val);
    334
    335		break;
    336	case 4:
    337		mask = LPC_HICRC_ID4IRQX_MASK | LPC_HICRC_TY4IRQX_MASK | LPC_HICRC_OBF4_AUTO_CLR;
    338		val = (id << LPC_HICRC_ID4IRQX_SHIFT) | (hw_type << LPC_HICRC_TY4IRQX_SHIFT);
    339		regmap_update_bits(priv->map, LPC_HICRC, mask, val);
    340		break;
    341	default:
    342		dev_warn(priv->kcs_bmc.dev,
    343			 "SerIRQ configuration not supported on KCS channel %d\n",
    344			 priv->kcs_bmc.channel);
    345		return -EINVAL;
    346	}
    347
    348	return 0;
    349}
    350
    351static void aspeed_kcs_enable_channel(struct kcs_bmc_device *kcs_bmc, bool enable)
    352{
    353	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
    354
    355	switch (kcs_bmc->channel) {
    356	case 1:
    357		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC1E, enable * LPC_HICR0_LPC1E);
    358		return;
    359	case 2:
    360		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC2E, enable * LPC_HICR0_LPC2E);
    361		return;
    362	case 3:
    363		regmap_update_bits(priv->map, LPC_HICR0, LPC_HICR0_LPC3E, enable * LPC_HICR0_LPC3E);
    364		regmap_update_bits(priv->map, LPC_HICR4,
    365				   LPC_HICR4_KCSENBL, enable * LPC_HICR4_KCSENBL);
    366		return;
    367	case 4:
    368		regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_LPC4E, enable * LPC_HICRB_LPC4E);
    369		return;
    370	default:
    371		pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
    372		return;
    373	}
    374}
    375
    376static void aspeed_kcs_check_obe(struct timer_list *timer)
    377{
    378	struct aspeed_kcs_bmc *priv = container_of(timer, struct aspeed_kcs_bmc, obe.timer);
    379	unsigned long flags;
    380	u8 str;
    381
    382	spin_lock_irqsave(&priv->obe.lock, flags);
    383	if (priv->obe.remove) {
    384		spin_unlock_irqrestore(&priv->obe.lock, flags);
    385		return;
    386	}
    387
    388	str = aspeed_kcs_inb(&priv->kcs_bmc, priv->kcs_bmc.ioreg.str);
    389	if (str & KCS_BMC_STR_OBF) {
    390		mod_timer(timer, jiffies + OBE_POLL_PERIOD);
    391		spin_unlock_irqrestore(&priv->obe.lock, flags);
    392		return;
    393	}
    394	spin_unlock_irqrestore(&priv->obe.lock, flags);
    395
    396	kcs_bmc_handle_event(&priv->kcs_bmc);
    397}
    398
    399static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)
    400{
    401	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
    402
    403	/* We don't have an OBE IRQ, emulate it */
    404	if (mask & KCS_BMC_EVENT_TYPE_OBE) {
    405		if (KCS_BMC_EVENT_TYPE_OBE & state)
    406			mod_timer(&priv->obe.timer, jiffies + OBE_POLL_PERIOD);
    407		else
    408			del_timer(&priv->obe.timer);
    409	}
    410
    411	if (mask & KCS_BMC_EVENT_TYPE_IBF) {
    412		const bool enable = !!(state & KCS_BMC_EVENT_TYPE_IBF);
    413
    414		switch (kcs_bmc->channel) {
    415		case 1:
    416			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE1,
    417					   enable * LPC_HICR2_IBFIE1);
    418			return;
    419		case 2:
    420			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE2,
    421					   enable * LPC_HICR2_IBFIE2);
    422			return;
    423		case 3:
    424			regmap_update_bits(priv->map, LPC_HICR2, LPC_HICR2_IBFIE3,
    425					   enable * LPC_HICR2_IBFIE3);
    426			return;
    427		case 4:
    428			regmap_update_bits(priv->map, LPC_HICRB, LPC_HICRB_IBFIE4,
    429					   enable * LPC_HICRB_IBFIE4);
    430			return;
    431		default:
    432			pr_warn("%s: Unsupported channel: %d", __func__, kcs_bmc->channel);
    433			return;
    434		}
    435	}
    436}
    437
    438static const struct kcs_bmc_device_ops aspeed_kcs_ops = {
    439	.irq_mask_update = aspeed_kcs_irq_mask_update,
    440	.io_inputb = aspeed_kcs_inb,
    441	.io_outputb = aspeed_kcs_outb,
    442	.io_updateb = aspeed_kcs_updateb,
    443};
    444
    445static irqreturn_t aspeed_kcs_irq(int irq, void *arg)
    446{
    447	struct kcs_bmc_device *kcs_bmc = arg;
    448
    449	return kcs_bmc_handle_event(kcs_bmc);
    450}
    451
    452static int aspeed_kcs_config_downstream_irq(struct kcs_bmc_device *kcs_bmc,
    453			struct platform_device *pdev)
    454{
    455	struct device *dev = &pdev->dev;
    456	int irq;
    457
    458	irq = platform_get_irq(pdev, 0);
    459	if (irq < 0)
    460		return irq;
    461
    462	return devm_request_irq(dev, irq, aspeed_kcs_irq, IRQF_SHARED,
    463				dev_name(dev), kcs_bmc);
    464}
    465
    466static const struct kcs_ioreg ast_kcs_bmc_ioregs[KCS_CHANNEL_MAX] = {
    467	{ .idr = LPC_IDR1, .odr = LPC_ODR1, .str = LPC_STR1 },
    468	{ .idr = LPC_IDR2, .odr = LPC_ODR2, .str = LPC_STR2 },
    469	{ .idr = LPC_IDR3, .odr = LPC_ODR3, .str = LPC_STR3 },
    470	{ .idr = LPC_IDR4, .odr = LPC_ODR4, .str = LPC_STR4 },
    471};
    472
    473static int aspeed_kcs_of_get_channel(struct platform_device *pdev)
    474{
    475	struct device_node *np;
    476	struct kcs_ioreg ioreg;
    477	const __be32 *reg;
    478	int i;
    479
    480	np = pdev->dev.of_node;
    481
    482	/* Don't translate addresses, we want offsets for the regmaps */
    483	reg = of_get_address(np, 0, NULL, NULL);
    484	if (!reg)
    485		return -EINVAL;
    486	ioreg.idr = be32_to_cpup(reg);
    487
    488	reg = of_get_address(np, 1, NULL, NULL);
    489	if (!reg)
    490		return -EINVAL;
    491	ioreg.odr = be32_to_cpup(reg);
    492
    493	reg = of_get_address(np, 2, NULL, NULL);
    494	if (!reg)
    495		return -EINVAL;
    496	ioreg.str = be32_to_cpup(reg);
    497
    498	for (i = 0; i < ARRAY_SIZE(ast_kcs_bmc_ioregs); i++) {
    499		if (!memcmp(&ast_kcs_bmc_ioregs[i], &ioreg, sizeof(ioreg)))
    500			return i + 1;
    501	}
    502	return -EINVAL;
    503}
    504
    505static int
    506aspeed_kcs_of_get_io_address(struct platform_device *pdev, u32 addrs[2])
    507{
    508	int rc;
    509
    510	rc = of_property_read_variable_u32_array(pdev->dev.of_node,
    511						 "aspeed,lpc-io-reg",
    512						 addrs, 1, 2);
    513	if (rc < 0) {
    514		dev_err(&pdev->dev, "No valid 'aspeed,lpc-io-reg' configured\n");
    515		return rc;
    516	}
    517
    518	if (addrs[0] > 0xffff) {
    519		dev_err(&pdev->dev, "Invalid data address in 'aspeed,lpc-io-reg'\n");
    520		return -EINVAL;
    521	}
    522
    523	if (rc == 2 && addrs[1] > 0xffff) {
    524		dev_err(&pdev->dev, "Invalid status address in 'aspeed,lpc-io-reg'\n");
    525		return -EINVAL;
    526	}
    527
    528	return rc;
    529}
    530
    531static int aspeed_kcs_probe(struct platform_device *pdev)
    532{
    533	struct kcs_bmc_device *kcs_bmc;
    534	struct aspeed_kcs_bmc *priv;
    535	struct device_node *np;
    536	bool have_upstream_irq;
    537	u32 upstream_irq[2];
    538	int rc, channel;
    539	int nr_addrs;
    540	u32 addrs[2];
    541
    542	np = pdev->dev.of_node->parent;
    543	if (!of_device_is_compatible(np, "aspeed,ast2400-lpc-v2") &&
    544	    !of_device_is_compatible(np, "aspeed,ast2500-lpc-v2") &&
    545	    !of_device_is_compatible(np, "aspeed,ast2600-lpc-v2")) {
    546		dev_err(&pdev->dev, "unsupported LPC device binding\n");
    547		return -ENODEV;
    548	}
    549
    550	channel = aspeed_kcs_of_get_channel(pdev);
    551	if (channel < 0)
    552		return channel;
    553
    554	nr_addrs = aspeed_kcs_of_get_io_address(pdev, addrs);
    555	if (nr_addrs < 0)
    556		return nr_addrs;
    557
    558	np = pdev->dev.of_node;
    559	rc = of_property_read_u32_array(np, "aspeed,lpc-interrupts", upstream_irq, 2);
    560	if (rc && rc != -EINVAL)
    561		return -EINVAL;
    562
    563	have_upstream_irq = !rc;
    564
    565	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
    566	if (!priv)
    567		return -ENOMEM;
    568
    569	kcs_bmc = &priv->kcs_bmc;
    570	kcs_bmc->dev = &pdev->dev;
    571	kcs_bmc->channel = channel;
    572	kcs_bmc->ioreg = ast_kcs_bmc_ioregs[channel - 1];
    573	kcs_bmc->ops = &aspeed_kcs_ops;
    574
    575	priv->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
    576	if (IS_ERR(priv->map)) {
    577		dev_err(&pdev->dev, "Couldn't get regmap\n");
    578		return -ENODEV;
    579	}
    580
    581	spin_lock_init(&priv->obe.lock);
    582	priv->obe.remove = false;
    583	timer_setup(&priv->obe.timer, aspeed_kcs_check_obe, 0);
    584
    585	rc = aspeed_kcs_set_address(kcs_bmc, addrs, nr_addrs);
    586	if (rc)
    587		return rc;
    588
    589	/* Host to BMC IRQ */
    590	rc = aspeed_kcs_config_downstream_irq(kcs_bmc, pdev);
    591	if (rc)
    592		return rc;
    593
    594	/* BMC to Host IRQ */
    595	if (have_upstream_irq) {
    596		rc = aspeed_kcs_config_upstream_irq(priv, upstream_irq[0], upstream_irq[1]);
    597		if (rc < 0)
    598			return rc;
    599	} else {
    600		priv->upstream_irq.mode = aspeed_kcs_irq_none;
    601	}
    602
    603	platform_set_drvdata(pdev, priv);
    604
    605	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
    606	aspeed_kcs_enable_channel(kcs_bmc, true);
    607
    608	rc = kcs_bmc_add_device(&priv->kcs_bmc);
    609	if (rc) {
    610		dev_warn(&pdev->dev, "Failed to register channel %d: %d\n", kcs_bmc->channel, rc);
    611		return rc;
    612	}
    613
    614	dev_info(&pdev->dev, "Initialised channel %d at 0x%x\n",
    615			kcs_bmc->channel, addrs[0]);
    616
    617	return 0;
    618}
    619
    620static int aspeed_kcs_remove(struct platform_device *pdev)
    621{
    622	struct aspeed_kcs_bmc *priv = platform_get_drvdata(pdev);
    623	struct kcs_bmc_device *kcs_bmc = &priv->kcs_bmc;
    624
    625	kcs_bmc_remove_device(kcs_bmc);
    626
    627	aspeed_kcs_enable_channel(kcs_bmc, false);
    628	aspeed_kcs_irq_mask_update(kcs_bmc, (KCS_BMC_EVENT_TYPE_IBF | KCS_BMC_EVENT_TYPE_OBE), 0);
    629
    630	/* Make sure it's proper dead */
    631	spin_lock_irq(&priv->obe.lock);
    632	priv->obe.remove = true;
    633	spin_unlock_irq(&priv->obe.lock);
    634	del_timer_sync(&priv->obe.timer);
    635
    636	return 0;
    637}
    638
    639static const struct of_device_id ast_kcs_bmc_match[] = {
    640	{ .compatible = "aspeed,ast2400-kcs-bmc-v2" },
    641	{ .compatible = "aspeed,ast2500-kcs-bmc-v2" },
    642	{ .compatible = "aspeed,ast2600-kcs-bmc" },
    643	{ }
    644};
    645MODULE_DEVICE_TABLE(of, ast_kcs_bmc_match);
    646
    647static struct platform_driver ast_kcs_bmc_driver = {
    648	.driver = {
    649		.name           = DEVICE_NAME,
    650		.of_match_table = ast_kcs_bmc_match,
    651	},
    652	.probe  = aspeed_kcs_probe,
    653	.remove = aspeed_kcs_remove,
    654};
    655module_platform_driver(ast_kcs_bmc_driver);
    656
    657MODULE_LICENSE("GPL v2");
    658MODULE_AUTHOR("Haiyue Wang <haiyue.wang@linux.intel.com>");
    659MODULE_AUTHOR("Andrew Jeffery <andrew@aj.id.au>");
    660MODULE_DESCRIPTION("Aspeed device interface to the KCS BMC device");