// SPDX-License-Identifier: GPL-2.0-only // Copyright (c) 2012-2017 ASPEED Technology Inc. // Copyright (c) 2018-2021 Intel Corporation #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* ASPEED PECI Registers */ /* Control Register */ #define ASPEED_PECI_CTRL 0x00 #define ASPEED_PECI_CTRL_SAMPLING_MASK GENMASK(19, 16) #define ASPEED_PECI_CTRL_RD_MODE_MASK GENMASK(13, 12) #define ASPEED_PECI_CTRL_RD_MODE_DBG BIT(13) #define ASPEED_PECI_CTRL_RD_MODE_COUNT BIT(12) #define ASPEED_PECI_CTRL_CLK_SRC_HCLK BIT(11) #define ASPEED_PECI_CTRL_CLK_DIV_MASK GENMASK(10, 8) #define ASPEED_PECI_CTRL_INVERT_OUT BIT(7) #define ASPEED_PECI_CTRL_INVERT_IN BIT(6) #define ASPEED_PECI_CTRL_BUS_CONTENTION_EN BIT(5) #define ASPEED_PECI_CTRL_PECI_EN BIT(4) #define ASPEED_PECI_CTRL_PECI_CLK_EN BIT(0) /* Timing Negotiation Register */ #define ASPEED_PECI_TIMING_NEGOTIATION 0x04 #define ASPEED_PECI_T_NEGO_MSG_MASK GENMASK(15, 8) #define ASPEED_PECI_T_NEGO_ADDR_MASK GENMASK(7, 0) /* Command Register */ #define ASPEED_PECI_CMD 0x08 #define ASPEED_PECI_CMD_PIN_MONITORING BIT(31) #define ASPEED_PECI_CMD_STS_MASK GENMASK(27, 24) #define ASPEED_PECI_CMD_STS_ADDR_T_NEGO 0x3 #define ASPEED_PECI_CMD_IDLE_MASK \ (ASPEED_PECI_CMD_STS_MASK | ASPEED_PECI_CMD_PIN_MONITORING) #define ASPEED_PECI_CMD_FIRE BIT(0) /* Read/Write Length Register */ #define ASPEED_PECI_RW_LENGTH 0x0c #define ASPEED_PECI_AW_FCS_EN BIT(31) #define ASPEED_PECI_RD_LEN_MASK GENMASK(23, 16) #define ASPEED_PECI_WR_LEN_MASK GENMASK(15, 8) #define ASPEED_PECI_TARGET_ADDR_MASK GENMASK(7, 0) /* Expected FCS Data Register */ #define ASPEED_PECI_EXPECTED_FCS 0x10 #define ASPEED_PECI_EXPECTED_RD_FCS_MASK GENMASK(23, 16) #define ASPEED_PECI_EXPECTED_AW_FCS_AUTO_MASK GENMASK(15, 8) #define ASPEED_PECI_EXPECTED_WR_FCS_MASK GENMASK(7, 0) /* Captured FCS Data Register */ #define ASPEED_PECI_CAPTURED_FCS 0x14 #define ASPEED_PECI_CAPTURED_RD_FCS_MASK GENMASK(23, 16) #define ASPEED_PECI_CAPTURED_WR_FCS_MASK GENMASK(7, 0) /* Interrupt Register */ #define ASPEED_PECI_INT_CTRL 0x18 #define ASPEED_PECI_TIMING_NEGO_SEL_MASK GENMASK(31, 30) #define ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO 0 #define ASPEED_PECI_2ND_BIT_OF_ADDR_NEGO 1 #define ASPEED_PECI_MESSAGE_NEGO 2 #define ASPEED_PECI_INT_MASK GENMASK(4, 0) #define ASPEED_PECI_INT_BUS_TIMEOUT BIT(4) #define ASPEED_PECI_INT_BUS_CONTENTION BIT(3) #define ASPEED_PECI_INT_WR_FCS_BAD BIT(2) #define ASPEED_PECI_INT_WR_FCS_ABORT BIT(1) #define ASPEED_PECI_INT_CMD_DONE BIT(0) /* Interrupt Status Register */ #define ASPEED_PECI_INT_STS 0x1c #define ASPEED_PECI_INT_TIMING_RESULT_MASK GENMASK(29, 16) /* bits[4..0]: Same bit fields in the 'Interrupt Register' */ /* Rx/Tx Data Buffer Registers */ #define ASPEED_PECI_WR_DATA0 0x20 #define ASPEED_PECI_WR_DATA1 0x24 #define ASPEED_PECI_WR_DATA2 0x28 #define ASPEED_PECI_WR_DATA3 0x2c #define ASPEED_PECI_RD_DATA0 0x30 #define ASPEED_PECI_RD_DATA1 0x34 #define ASPEED_PECI_RD_DATA2 0x38 #define ASPEED_PECI_RD_DATA3 0x3c #define ASPEED_PECI_WR_DATA4 0x40 #define ASPEED_PECI_WR_DATA5 0x44 #define ASPEED_PECI_WR_DATA6 0x48 #define ASPEED_PECI_WR_DATA7 0x4c #define ASPEED_PECI_RD_DATA4 0x50 #define ASPEED_PECI_RD_DATA5 0x54 #define ASPEED_PECI_RD_DATA6 0x58 #define ASPEED_PECI_RD_DATA7 0x5c #define ASPEED_PECI_DATA_BUF_SIZE_MAX 32 /* Timing Negotiation */ #define ASPEED_PECI_CLK_FREQUENCY_MIN 2000 #define ASPEED_PECI_CLK_FREQUENCY_DEFAULT 1000000 #define ASPEED_PECI_CLK_FREQUENCY_MAX 2000000 #define ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT 8 /* Timeout */ #define ASPEED_PECI_IDLE_CHECK_TIMEOUT_US (50 * USEC_PER_MSEC) #define ASPEED_PECI_IDLE_CHECK_INTERVAL_US (10 * USEC_PER_MSEC) #define ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT 1000 #define ASPEED_PECI_CMD_TIMEOUT_MS_MAX 1000 #define ASPEED_PECI_CLK_DIV1(msg_timing) (4 * (msg_timing) + 1) #define ASPEED_PECI_CLK_DIV2(clk_div_exp) BIT(clk_div_exp) #define ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp) \ (4 * ASPEED_PECI_CLK_DIV1(msg_timing) * ASPEED_PECI_CLK_DIV2(clk_div_exp)) struct aspeed_peci { struct peci_controller *controller; struct device *dev; void __iomem *base; struct reset_control *rst; int irq; spinlock_t lock; /* to sync completion status handling */ struct completion xfer_complete; struct clk *clk; u32 clk_frequency; u32 status; u32 cmd_timeout_ms; }; struct clk_aspeed_peci { struct clk_hw hw; struct aspeed_peci *aspeed_peci; }; static void aspeed_peci_controller_enable(struct aspeed_peci *priv) { u32 val = readl(priv->base + ASPEED_PECI_CTRL); val |= ASPEED_PECI_CTRL_PECI_CLK_EN; val |= ASPEED_PECI_CTRL_PECI_EN; writel(val, priv->base + ASPEED_PECI_CTRL); } static void aspeed_peci_init_regs(struct aspeed_peci *priv) { u32 val; /* Clear interrupts */ writel(ASPEED_PECI_INT_MASK, priv->base + ASPEED_PECI_INT_STS); /* Set timing negotiation mode and enable interrupts */ val = FIELD_PREP(ASPEED_PECI_TIMING_NEGO_SEL_MASK, ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO); val |= ASPEED_PECI_INT_MASK; writel(val, priv->base + ASPEED_PECI_INT_CTRL); val = FIELD_PREP(ASPEED_PECI_CTRL_SAMPLING_MASK, ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT); writel(val, priv->base + ASPEED_PECI_CTRL); } static int aspeed_peci_check_idle(struct aspeed_peci *priv) { u32 cmd_sts = readl(priv->base + ASPEED_PECI_CMD); int ret; /* * Under normal circumstances, we expect to be idle here. * In case there were any errors/timeouts that led to the situation * where the hardware is not in idle state - we need to reset and * reinitialize it to avoid potential controller hang. */ if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts)) { ret = reset_control_assert(priv->rst); if (ret) { dev_err(priv->dev, "cannot assert reset control\n"); return ret; } ret = reset_control_deassert(priv->rst); if (ret) { dev_err(priv->dev, "cannot deassert reset control\n"); return ret; } aspeed_peci_init_regs(priv); ret = clk_set_rate(priv->clk, priv->clk_frequency); if (ret < 0) { dev_err(priv->dev, "cannot set clock frequency\n"); return ret; } aspeed_peci_controller_enable(priv); } return readl_poll_timeout(priv->base + ASPEED_PECI_CMD, cmd_sts, !(cmd_sts & ASPEED_PECI_CMD_IDLE_MASK), ASPEED_PECI_IDLE_CHECK_INTERVAL_US, ASPEED_PECI_IDLE_CHECK_TIMEOUT_US); } static int aspeed_peci_xfer(struct peci_controller *controller, u8 addr, struct peci_request *req) { struct aspeed_peci *priv = dev_get_drvdata(controller->dev.parent); unsigned long timeout = msecs_to_jiffies(priv->cmd_timeout_ms); u32 peci_head; int ret, i; if (req->tx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX || req->rx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX) return -EINVAL; /* Check command sts and bus idle state */ ret = aspeed_peci_check_idle(priv); if (ret) return ret; /* -ETIMEDOUT */ spin_lock_irq(&priv->lock); reinit_completion(&priv->xfer_complete); peci_head = FIELD_PREP(ASPEED_PECI_TARGET_ADDR_MASK, addr) | FIELD_PREP(ASPEED_PECI_WR_LEN_MASK, req->tx.len) | FIELD_PREP(ASPEED_PECI_RD_LEN_MASK, req->rx.len); writel(peci_head, priv->base + ASPEED_PECI_RW_LENGTH); for (i = 0; i < req->tx.len; i += 4) { u32 reg = (i < 16 ? ASPEED_PECI_WR_DATA0 : ASPEED_PECI_WR_DATA4) + i % 16; writel(get_unaligned_le32(&req->tx.buf[i]), priv->base + reg); } #if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) dev_dbg(priv->dev, "HEAD : %#08x\n", peci_head); print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, req->tx.buf, req->tx.len); #endif priv->status = 0; writel(ASPEED_PECI_CMD_FIRE, priv->base + ASPEED_PECI_CMD); spin_unlock_irq(&priv->lock); ret = wait_for_completion_interruptible_timeout(&priv->xfer_complete, timeout); if (ret < 0) return ret; if (ret == 0) { dev_dbg(priv->dev, "timeout waiting for a response\n"); return -ETIMEDOUT; } spin_lock_irq(&priv->lock); if (priv->status != ASPEED_PECI_INT_CMD_DONE) { spin_unlock_irq(&priv->lock); dev_dbg(priv->dev, "no valid response, status: %#02x\n", priv->status); return -EIO; } spin_unlock_irq(&priv->lock); /* * We need to use dword reads for register access, make sure that the * buffer size is multiple of 4-bytes. */ BUILD_BUG_ON(PECI_REQUEST_MAX_BUF_SIZE % 4); for (i = 0; i < req->rx.len; i += 4) { u32 reg = (i < 16 ? ASPEED_PECI_RD_DATA0 : ASPEED_PECI_RD_DATA4) + i % 16; u32 rx_data = readl(priv->base + reg); put_unaligned_le32(rx_data, &req->rx.buf[i]); } #if IS_ENABLED(CONFIG_DYNAMIC_DEBUG) print_hex_dump_bytes("RX : ", DUMP_PREFIX_NONE, req->rx.buf, req->rx.len); #endif return 0; } static irqreturn_t aspeed_peci_irq_handler(int irq, void *arg) { struct aspeed_peci *priv = arg; u32 status; spin_lock(&priv->lock); status = readl(priv->base + ASPEED_PECI_INT_STS); writel(status, priv->base + ASPEED_PECI_INT_STS); priv->status |= (status & ASPEED_PECI_INT_MASK); /* * All commands should be ended up with a ASPEED_PECI_INT_CMD_DONE bit * set even in an error case. */ if (status & ASPEED_PECI_INT_CMD_DONE) complete(&priv->xfer_complete); writel(0, priv->base + ASPEED_PECI_CMD); spin_unlock(&priv->lock); return IRQ_HANDLED; } static void clk_aspeed_peci_find_div_values(unsigned long rate, int *msg_timing, int *clk_div_exp) { unsigned long best_diff = ~0ul, diff; int msg_timing_temp, clk_div_exp_temp, i, j; for (i = 1; i <= 255; i++) for (j = 0; j < 8; j++) { diff = abs(rate - ASPEED_PECI_CLK_DIV1(i) * ASPEED_PECI_CLK_DIV2(j)); if (diff < best_diff) { msg_timing_temp = i; clk_div_exp_temp = j; best_diff = diff; } } *msg_timing = msg_timing_temp; *clk_div_exp = clk_div_exp_temp; } static int clk_aspeed_peci_get_div(unsigned long rate, const unsigned long *prate) { unsigned long this_rate = *prate / (4 * rate); int msg_timing, clk_div_exp; clk_aspeed_peci_find_div_values(this_rate, &msg_timing, &clk_div_exp); return ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp); } static int clk_aspeed_peci_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long prate) { struct clk_aspeed_peci *peci_clk = container_of(hw, struct clk_aspeed_peci, hw); struct aspeed_peci *aspeed_peci = peci_clk->aspeed_peci; unsigned long this_rate = prate / (4 * rate); int clk_div_exp, msg_timing; u32 val; clk_aspeed_peci_find_div_values(this_rate, &msg_timing, &clk_div_exp); val = readl(aspeed_peci->base + ASPEED_PECI_CTRL); val &= ~ASPEED_PECI_CTRL_CLK_DIV_MASK; val |= FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, clk_div_exp); writel(val, aspeed_peci->base + ASPEED_PECI_CTRL); val = FIELD_PREP(ASPEED_PECI_T_NEGO_MSG_MASK, msg_timing); val |= FIELD_PREP(ASPEED_PECI_T_NEGO_ADDR_MASK, msg_timing); writel(val, aspeed_peci->base + ASPEED_PECI_TIMING_NEGOTIATION); return 0; } static long clk_aspeed_peci_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { int div = clk_aspeed_peci_get_div(rate, prate); return DIV_ROUND_UP_ULL(*prate, div); } static unsigned long clk_aspeed_peci_recalc_rate(struct clk_hw *hw, unsigned long prate) { struct clk_aspeed_peci *peci_clk = container_of(hw, struct clk_aspeed_peci, hw); struct aspeed_peci *aspeed_peci = peci_clk->aspeed_peci; int div, msg_timing, addr_timing, clk_div_exp; u32 reg; reg = readl(aspeed_peci->base + ASPEED_PECI_TIMING_NEGOTIATION); msg_timing = FIELD_GET(ASPEED_PECI_T_NEGO_MSG_MASK, reg); addr_timing = FIELD_GET(ASPEED_PECI_T_NEGO_ADDR_MASK, reg); if (msg_timing != addr_timing) return 0; reg = readl(aspeed_peci->base + ASPEED_PECI_CTRL); clk_div_exp = FIELD_GET(ASPEED_PECI_CTRL_CLK_DIV_MASK, reg); div = ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp); return DIV_ROUND_UP_ULL(prate, div); } static const struct clk_ops clk_aspeed_peci_ops = { .set_rate = clk_aspeed_peci_set_rate, .round_rate = clk_aspeed_peci_round_rate, .recalc_rate = clk_aspeed_peci_recalc_rate, }; /* * PECI HW contains a clock divider which is a combination of: * div0: 4 (fixed divider) * div1: x + 1 * div2: 1 << y * In other words, out_clk = in_clk / (div0 * div1 * div2) * The resulting frequency is used by PECI Controller to drive the PECI bus to * negotiate optimal transfer rate. */ static struct clk *devm_aspeed_peci_register_clk_div(struct device *dev, struct clk *parent, struct aspeed_peci *priv) { struct clk_aspeed_peci *peci_clk; struct clk_init_data init; const char *parent_name; char name[32]; int ret; snprintf(name, sizeof(name), "%s_div", dev_name(dev)); parent_name = __clk_get_name(parent); init.ops = &clk_aspeed_peci_ops; init.name = name; init.parent_names = (const char* []) { parent_name }; init.num_parents = 1; init.flags = 0; peci_clk = devm_kzalloc(dev, sizeof(struct clk_aspeed_peci), GFP_KERNEL); if (!peci_clk) return ERR_PTR(-ENOMEM); peci_clk->hw.init = &init; peci_clk->aspeed_peci = priv; ret = devm_clk_hw_register(dev, &peci_clk->hw); if (ret) return ERR_PTR(ret); return peci_clk->hw.clk; } static void aspeed_peci_property_sanitize(struct device *dev, const char *propname, u32 min, u32 max, u32 default_val, u32 *propval) { u32 val; int ret; ret = device_property_read_u32(dev, propname, &val); if (ret) { val = default_val; } else if (val > max || val < min) { dev_warn(dev, "invalid %s: %u, falling back to: %u\n", propname, val, default_val); val = default_val; } *propval = val; } static void aspeed_peci_property_setup(struct aspeed_peci *priv) { aspeed_peci_property_sanitize(priv->dev, "clock-frequency", ASPEED_PECI_CLK_FREQUENCY_MIN, ASPEED_PECI_CLK_FREQUENCY_MAX, ASPEED_PECI_CLK_FREQUENCY_DEFAULT, &priv->clk_frequency); aspeed_peci_property_sanitize(priv->dev, "cmd-timeout-ms", 1, ASPEED_PECI_CMD_TIMEOUT_MS_MAX, ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT, &priv->cmd_timeout_ms); } static const struct peci_controller_ops aspeed_ops = { .xfer = aspeed_peci_xfer, }; static void aspeed_peci_reset_control_release(void *data) { reset_control_assert(data); } static int devm_aspeed_peci_reset_control_deassert(struct device *dev, struct reset_control *rst) { int ret; ret = reset_control_deassert(rst); if (ret) return ret; return devm_add_action_or_reset(dev, aspeed_peci_reset_control_release, rst); } static void aspeed_peci_clk_release(void *data) { clk_disable_unprepare(data); } static int devm_aspeed_peci_clk_enable(struct device *dev, struct clk *clk) { int ret; ret = clk_prepare_enable(clk); if (ret) return ret; return devm_add_action_or_reset(dev, aspeed_peci_clk_release, clk); } static int aspeed_peci_probe(struct platform_device *pdev) { struct peci_controller *controller; struct aspeed_peci *priv; struct clk *ref_clk; int ret; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->dev = &pdev->dev; dev_set_drvdata(priv->dev, priv); priv->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(priv->base)) return PTR_ERR(priv->base); priv->irq = platform_get_irq(pdev, 0); if (priv->irq < 0) return priv->irq; ret = devm_request_irq(&pdev->dev, priv->irq, aspeed_peci_irq_handler, 0, "peci-aspeed", priv); if (ret) return ret; init_completion(&priv->xfer_complete); spin_lock_init(&priv->lock); priv->rst = devm_reset_control_get(&pdev->dev, NULL); if (IS_ERR(priv->rst)) return dev_err_probe(priv->dev, PTR_ERR(priv->rst), "failed to get reset control\n"); ret = devm_aspeed_peci_reset_control_deassert(priv->dev, priv->rst); if (ret) return dev_err_probe(priv->dev, ret, "cannot deassert reset control\n"); aspeed_peci_property_setup(priv); aspeed_peci_init_regs(priv); ref_clk = devm_clk_get(priv->dev, NULL); if (IS_ERR(ref_clk)) return dev_err_probe(priv->dev, PTR_ERR(ref_clk), "failed to get ref clock\n"); priv->clk = devm_aspeed_peci_register_clk_div(priv->dev, ref_clk, priv); if (IS_ERR(priv->clk)) return dev_err_probe(priv->dev, PTR_ERR(priv->clk), "cannot register clock\n"); ret = clk_set_rate(priv->clk, priv->clk_frequency); if (ret < 0) return dev_err_probe(priv->dev, ret, "cannot set clock frequency\n"); ret = devm_aspeed_peci_clk_enable(priv->dev, priv->clk); if (ret) return dev_err_probe(priv->dev, ret, "failed to enable clock\n"); aspeed_peci_controller_enable(priv); controller = devm_peci_controller_add(priv->dev, &aspeed_ops); if (IS_ERR(controller)) return dev_err_probe(priv->dev, PTR_ERR(controller), "failed to add aspeed peci controller\n"); priv->controller = controller; return 0; } static const struct of_device_id aspeed_peci_of_table[] = { { .compatible = "aspeed,ast2400-peci", }, { .compatible = "aspeed,ast2500-peci", }, { .compatible = "aspeed,ast2600-peci", }, { } }; MODULE_DEVICE_TABLE(of, aspeed_peci_of_table); static struct platform_driver aspeed_peci_driver = { .probe = aspeed_peci_probe, .driver = { .name = "peci-aspeed", .of_match_table = aspeed_peci_of_table, }, }; module_platform_driver(aspeed_peci_driver); MODULE_AUTHOR("Ryan Chen "); MODULE_AUTHOR("Jae Hyun Yoo "); MODULE_DESCRIPTION("ASPEED PECI driver"); MODULE_LICENSE("GPL"); MODULE_IMPORT_NS("PECI");