@@ -10,3 +10,30 @@ config PECI
The Platform Environment Control Interface (PECI) is a one-wire bus
interface that provides a communication channel from Intel processors
and chipset components to external monitoring or control devices.
+
+ If you want PECI support, you should say Y here and also to the
+ specific driver for your bus adapter(s) below.
+
+if PECI
+
+#
+# PECI hardware bus configuration
+#
+
+menu "PECI Hardware Bus support"
+
+config PECI_ASPEED
+ tristate "ASPEED PECI support"
+ select REGMAP_MMIO
+ depends on OF
+ depends on ARCH_ASPEED || COMPILE_TEST
+ help
+ Say Y here if you want support for the Platform Environment Control
+ Interface (PECI) bus adapter driver on the ASPEED SoCs.
+
+ This support is also available as a module. If so, the module
+ will be called peci-aspeed.
+
+endmenu
+
+endif # PECI
@@ -4,3 +4,6 @@
# Core functionality
obj-$(CONFIG_PECI) += peci-core.o
+
+# Hardware specific bus drivers
+obj-$(CONFIG_PECI_ASPEED) += peci-aspeed.o
new file mode 100644
@@ -0,0 +1,498 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2012-2017 ASPEED Technology Inc.
+// Copyright (c) 2018 Intel Corporation
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/peci.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+/* ASPEED PECI Registers */
+#define ASPEED_PECI_CTRL 0x00
+#define ASPEED_PECI_TIMING 0x04
+#define ASPEED_PECI_CMD 0x08
+#define ASPEED_PECI_CMD_CTRL 0x0c
+#define ASPEED_PECI_EXP_FCS 0x10
+#define ASPEED_PECI_CAP_FCS 0x14
+#define ASPEED_PECI_INT_CTRL 0x18
+#define ASPEED_PECI_INT_STS 0x1c
+#define ASPEED_PECI_W_DATA0 0x20
+#define ASPEED_PECI_W_DATA1 0x24
+#define ASPEED_PECI_W_DATA2 0x28
+#define ASPEED_PECI_W_DATA3 0x2c
+#define ASPEED_PECI_R_DATA0 0x30
+#define ASPEED_PECI_R_DATA1 0x34
+#define ASPEED_PECI_R_DATA2 0x38
+#define ASPEED_PECI_R_DATA3 0x3c
+#define ASPEED_PECI_W_DATA4 0x40
+#define ASPEED_PECI_W_DATA5 0x44
+#define ASPEED_PECI_W_DATA6 0x48
+#define ASPEED_PECI_W_DATA7 0x4c
+#define ASPEED_PECI_R_DATA4 0x50
+#define ASPEED_PECI_R_DATA5 0x54
+#define ASPEED_PECI_R_DATA6 0x58
+#define ASPEED_PECI_R_DATA7 0x5c
+
+/* ASPEED_PECI_CTRL - 0x00 : Control Register */
+#define PECI_CTRL_SAMPLING_MASK GENMASK(19, 16)
+#define PECI_CTRL_READ_MODE_MASK GENMASK(13, 12)
+#define PECI_CTRL_READ_MODE_COUNT BIT(12)
+#define PECI_CTRL_READ_MODE_DBG BIT(13)
+#define PECI_CTRL_CLK_SOURCE_MASK BIT(11)
+#define PECI_CTRL_CLK_DIV_MASK GENMASK(10, 8)
+#define PECI_CTRL_INVERT_OUT BIT(7)
+#define PECI_CTRL_INVERT_IN BIT(6)
+#define PECI_CTRL_BUS_CONTENT_EN BIT(5)
+#define PECI_CTRL_PECI_EN BIT(4)
+#define PECI_CTRL_PECI_CLK_EN BIT(0)
+
+/* ASPEED_PECI_TIMING - 0x04 : Timing Negotiation Register */
+#define PECI_TIMING_MESSAGE_MASK GENMASK(15, 8)
+#define PECI_TIMING_ADDRESS_MASK GENMASK(7, 0)
+
+/* ASPEED_PECI_CMD - 0x08 : Command Register */
+#define PECI_CMD_PIN_MON BIT(31)
+#define PECI_CMD_STS_MASK GENMASK(27, 24)
+#define PECI_CMD_IDLE_MASK (PECI_CMD_STS_MASK | PECI_CMD_PIN_MON)
+#define PECI_CMD_FIRE BIT(0)
+
+/* ASPEED_PECI_LEN - 0x0C : Read/Write Length Register */
+#define PECI_AW_FCS_EN BIT(31)
+#define PECI_READ_LEN_MASK GENMASK(23, 16)
+#define PECI_WRITE_LEN_MASK GENMASK(15, 8)
+#define PECI_TAGET_ADDR_MASK GENMASK(7, 0)
+
+/* ASPEED_PECI_EXP_FCS - 0x10 : Expected FCS Data Register */
+#define PECI_EXPECT_READ_FCS_MASK GENMASK(23, 16)
+#define PECI_EXPECT_AW_FCS_AUTO_MASK GENMASK(15, 8)
+#define PECI_EXPECT_WRITE_FCS_MASK GENMASK(7, 0)
+
+/* ASPEED_PECI_CAP_FCS - 0x14 : Captured FCS Data Register */
+#define PECI_CAPTURE_READ_FCS_MASK GENMASK(23, 16)
+#define PECI_CAPTURE_WRITE_FCS_MASK GENMASK(7, 0)
+
+/* ASPEED_PECI_INT_CTRL/STS - 0x18/0x1c : Interrupt Register */
+#define PECI_INT_TIMING_RESULT_MASK GENMASK(31, 30)
+#define PECI_INT_TIMEOUT BIT(4)
+#define PECI_INT_CONNECT BIT(3)
+#define PECI_INT_W_FCS_BAD BIT(2)
+#define PECI_INT_W_FCS_ABORT BIT(1)
+#define PECI_INT_CMD_DONE BIT(0)
+
+#define PECI_INT_MASK (PECI_INT_TIMEOUT | PECI_INT_CONNECT | \
+ PECI_INT_W_FCS_BAD | PECI_INT_W_FCS_ABORT | \
+ PECI_INT_CMD_DONE)
+
+#define PECI_IDLE_CHECK_TIMEOUT_USEC 50000
+#define PECI_IDLE_CHECK_INTERVAL_USEC 10000
+
+#define PECI_RD_SAMPLING_POINT_DEFAULT 8
+#define PECI_RD_SAMPLING_POINT_MAX 15
+#define PECI_CLK_DIV_DEFAULT 0
+#define PECI_CLK_DIV_MAX 7
+#define PECI_MSG_TIMING_DEFAULT 1
+#define PECI_MSG_TIMING_MAX 255
+#define PECI_ADDR_TIMING_DEFAULT 1
+#define PECI_ADDR_TIMING_MAX 255
+#define PECI_CMD_TIMEOUT_MS_DEFAULT 1000
+#define PECI_CMD_TIMEOUT_MS_MAX 60000
+
+struct aspeed_peci {
+ struct peci_adapter *adapter;
+ struct device *dev;
+ struct regmap *regmap;
+ struct reset_control *rst;
+ int irq;
+ spinlock_t lock; /* to sync completion status handling */
+ struct completion xfer_complete;
+ u32 status;
+ u32 cmd_timeout_ms;
+};
+
+static int aspeed_peci_xfer_native(struct aspeed_peci *priv,
+ struct peci_xfer_msg *msg)
+{
+ long err, timeout = msecs_to_jiffies(priv->cmd_timeout_ms);
+ u32 peci_head, peci_state, rx_data, cmd_sts;
+ unsigned long flags;
+ int i, rc;
+ uint reg;
+
+ /* Check command sts and bus idle state */
+ rc = regmap_read_poll_timeout(priv->regmap, ASPEED_PECI_CMD, cmd_sts,
+ !(cmd_sts & PECI_CMD_IDLE_MASK),
+ PECI_IDLE_CHECK_INTERVAL_USEC,
+ PECI_IDLE_CHECK_TIMEOUT_USEC);
+ if (rc)
+ return rc; /* -ETIMEDOUT */
+
+ spin_lock_irqsave(&priv->lock, flags);
+ reinit_completion(&priv->xfer_complete);
+
+ peci_head = FIELD_PREP(PECI_TAGET_ADDR_MASK, msg->addr) |
+ FIELD_PREP(PECI_WRITE_LEN_MASK, msg->tx_len) |
+ FIELD_PREP(PECI_READ_LEN_MASK, msg->rx_len);
+
+ regmap_write(priv->regmap, ASPEED_PECI_CMD_CTRL, peci_head);
+
+ for (i = 0; i < msg->tx_len; i += 4) {
+ reg = i < 16 ? ASPEED_PECI_W_DATA0 + i % 16 :
+ ASPEED_PECI_W_DATA4 + i % 16;
+ regmap_write(priv->regmap, reg,
+ le32_to_cpup((__le32 *)&msg->tx_buf[i]));
+ }
+
+ dev_dbg(priv->dev, "HEAD : 0x%08x\n", peci_head);
+ print_hex_dump_debug("TX : ", DUMP_PREFIX_NONE, 16, 1,
+ msg->tx_buf, msg->tx_len, true);
+
+ priv->status = 0;
+ regmap_write(priv->regmap, ASPEED_PECI_CMD, PECI_CMD_FIRE);
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ err = wait_for_completion_interruptible_timeout(&priv->xfer_complete,
+ timeout);
+
+ spin_lock_irqsave(&priv->lock, flags);
+ dev_dbg(priv->dev, "INT_STS : 0x%08x\n", priv->status);
+ regmap_read(priv->regmap, ASPEED_PECI_CMD, &peci_state);
+ dev_dbg(priv->dev, "PECI_STATE : 0x%lx\n",
+ FIELD_GET(PECI_CMD_STS_MASK, peci_state));
+
+ regmap_write(priv->regmap, ASPEED_PECI_CMD, 0);
+
+ if (err <= 0 || priv->status != PECI_INT_CMD_DONE) {
+ if (err < 0) { /* -ERESTARTSYS */
+ rc = (int)err;
+ goto err_irqrestore;
+ } else if (err == 0) {
+ dev_dbg(priv->dev, "Timeout waiting for a response!\n");
+ rc = -ETIMEDOUT;
+ goto err_irqrestore;
+ }
+
+ dev_dbg(priv->dev, "No valid response!\n");
+ rc = -EIO;
+ goto err_irqrestore;
+ }
+
+ /**
+ * Note that rx_len and rx_buf size can be an odd number.
+ * Byte handling is more efficient.
+ */
+ for (i = 0; i < msg->rx_len; i++) {
+ u8 byte_offset = i % 4;
+
+ if (byte_offset == 0) {
+ reg = i < 16 ? ASPEED_PECI_R_DATA0 + i % 16 :
+ ASPEED_PECI_R_DATA4 + i % 16;
+ regmap_read(priv->regmap, reg, &rx_data);
+ }
+
+ msg->rx_buf[i] = (u8)(rx_data >> (byte_offset << 3));
+ }
+
+ print_hex_dump_debug("RX : ", DUMP_PREFIX_NONE, 16, 1,
+ msg->rx_buf, msg->rx_len, true);
+
+ regmap_read(priv->regmap, ASPEED_PECI_CMD, &peci_state);
+ dev_dbg(priv->dev, "PECI_STATE : 0x%lx\n",
+ FIELD_GET(PECI_CMD_STS_MASK, peci_state));
+ dev_dbg(priv->dev, "------------------------\n");
+
+err_irqrestore:
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return rc;
+}
+
+static irqreturn_t aspeed_peci_irq_handler(int irq, void *arg)
+{
+ struct aspeed_peci *priv = arg;
+ u32 status_ack = 0;
+ u32 status;
+
+ spin_lock(&priv->lock);
+ regmap_read(priv->regmap, ASPEED_PECI_INT_STS, &status);
+ priv->status |= (status & PECI_INT_MASK);
+
+ /**
+ * In most cases, interrupt bits will be set one by one but also note
+ * that multiple interrupt bits could be set at the same time.
+ */
+ if (status & PECI_INT_TIMEOUT) {
+ dev_dbg(priv->dev, "PECI_INT_TIMEOUT\n");
+ status_ack |= PECI_INT_TIMEOUT;
+ }
+
+ if (status & PECI_INT_CONNECT) {
+ dev_dbg(priv->dev, "PECI_INT_CONNECT\n");
+ status_ack |= PECI_INT_CONNECT;
+ }
+
+ if (status & PECI_INT_W_FCS_BAD) {
+ dev_dbg(priv->dev, "PECI_INT_W_FCS_BAD\n");
+ status_ack |= PECI_INT_W_FCS_BAD;
+ }
+
+ if (status & PECI_INT_W_FCS_ABORT) {
+ dev_dbg(priv->dev, "PECI_INT_W_FCS_ABORT\n");
+ status_ack |= PECI_INT_W_FCS_ABORT;
+ }
+
+ /**
+ * All commands should be ended up with a PECI_INT_CMD_DONE bit set
+ * even in an error case.
+ */
+ if (status & PECI_INT_CMD_DONE) {
+ dev_dbg(priv->dev, "PECI_INT_CMD_DONE\n");
+ status_ack |= PECI_INT_CMD_DONE;
+ complete(&priv->xfer_complete);
+ }
+
+ regmap_write(priv->regmap, ASPEED_PECI_INT_STS, status_ack);
+ spin_unlock(&priv->lock);
+ return IRQ_HANDLED;
+}
+
+static int aspeed_peci_init_ctrl(struct aspeed_peci *priv)
+{
+ u32 msg_timing, addr_timing, rd_sampling_point;
+ u32 clk_freq, clk_divisor, clk_div_val = 0;
+ struct clk *clkin;
+ int ret;
+
+ clkin = devm_clk_get(priv->dev, NULL);
+ if (IS_ERR(clkin)) {
+ dev_err(priv->dev, "Failed to get clk source.\n");
+ return PTR_ERR(clkin);
+ }
+
+ ret = of_property_read_u32(priv->dev->of_node, "clock-frequency",
+ &clk_freq);
+ if (ret) {
+ dev_err(priv->dev,
+ "Could not read clock-frequency property.\n");
+ return ret;
+ }
+
+ clk_divisor = clk_get_rate(clkin) / clk_freq;
+ devm_clk_put(priv->dev, clkin);
+
+ while ((clk_divisor >> 1) && (clk_div_val < PECI_CLK_DIV_MAX))
+ clk_div_val++;
+
+ ret = of_property_read_u32(priv->dev->of_node, "msg-timing",
+ &msg_timing);
+ if (ret || msg_timing > PECI_MSG_TIMING_MAX) {
+ if (!ret)
+ dev_warn(priv->dev,
+ "Invalid msg-timing : %u, Use default : %u\n",
+ msg_timing, PECI_MSG_TIMING_DEFAULT);
+ msg_timing = PECI_MSG_TIMING_DEFAULT;
+ }
+
+ ret = of_property_read_u32(priv->dev->of_node, "addr-timing",
+ &addr_timing);
+ if (ret || addr_timing > PECI_ADDR_TIMING_MAX) {
+ if (!ret)
+ dev_warn(priv->dev,
+ "Invalid addr-timing : %u, Use default : %u\n",
+ addr_timing, PECI_ADDR_TIMING_DEFAULT);
+ addr_timing = PECI_ADDR_TIMING_DEFAULT;
+ }
+
+ ret = of_property_read_u32(priv->dev->of_node, "rd-sampling-point",
+ &rd_sampling_point);
+ if (ret || rd_sampling_point > PECI_RD_SAMPLING_POINT_MAX) {
+ if (!ret)
+ dev_warn(priv->dev,
+ "Invalid rd-sampling-point : %u. Use default : %u\n",
+ rd_sampling_point,
+ PECI_RD_SAMPLING_POINT_DEFAULT);
+ rd_sampling_point = PECI_RD_SAMPLING_POINT_DEFAULT;
+ }
+
+ ret = of_property_read_u32(priv->dev->of_node, "cmd-timeout-ms",
+ &priv->cmd_timeout_ms);
+ if (ret || priv->cmd_timeout_ms > PECI_CMD_TIMEOUT_MS_MAX ||
+ priv->cmd_timeout_ms == 0) {
+ if (!ret)
+ dev_warn(priv->dev,
+ "Invalid cmd-timeout-ms : %u. Use default : %u\n",
+ priv->cmd_timeout_ms,
+ PECI_CMD_TIMEOUT_MS_DEFAULT);
+ priv->cmd_timeout_ms = PECI_CMD_TIMEOUT_MS_DEFAULT;
+ }
+
+ regmap_write(priv->regmap, ASPEED_PECI_CTRL,
+ FIELD_PREP(PECI_CTRL_CLK_DIV_MASK, PECI_CLK_DIV_DEFAULT) |
+ PECI_CTRL_PECI_CLK_EN);
+
+ /**
+ * Timing negotiation period setting.
+ * The unit of the programmed value is 4 times of PECI clock period.
+ */
+ regmap_write(priv->regmap, ASPEED_PECI_TIMING,
+ FIELD_PREP(PECI_TIMING_MESSAGE_MASK, msg_timing) |
+ FIELD_PREP(PECI_TIMING_ADDRESS_MASK, addr_timing));
+
+ /* Clear interrupts */
+ regmap_write(priv->regmap, ASPEED_PECI_INT_STS, PECI_INT_MASK);
+
+ /* Enable interrupts */
+ regmap_write(priv->regmap, ASPEED_PECI_INT_CTRL, PECI_INT_MASK);
+
+ /* Read sampling point and clock speed setting */
+ regmap_write(priv->regmap, ASPEED_PECI_CTRL,
+ FIELD_PREP(PECI_CTRL_SAMPLING_MASK, rd_sampling_point) |
+ FIELD_PREP(PECI_CTRL_CLK_DIV_MASK, clk_div_val) |
+ PECI_CTRL_PECI_EN | PECI_CTRL_PECI_CLK_EN);
+
+ return 0;
+}
+
+static const struct regmap_config aspeed_peci_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .max_register = ASPEED_PECI_R_DATA7,
+ .val_format_endian = REGMAP_ENDIAN_LITTLE,
+ .fast_io = true,
+};
+
+static int aspeed_peci_xfer(struct peci_adapter *adapter,
+ struct peci_xfer_msg *msg)
+{
+ struct aspeed_peci *priv = peci_get_adapdata(adapter);
+
+ return aspeed_peci_xfer_native(priv, msg);
+}
+
+static int aspeed_peci_probe(struct platform_device *pdev)
+{
+ struct peci_adapter *adapter;
+ struct aspeed_peci *priv;
+ struct resource *res;
+ void __iomem *base;
+ u32 cmd_sts;
+ int ret;
+
+ adapter = peci_alloc_adapter(&pdev->dev, sizeof(*priv));
+ if (!adapter)
+ return -ENOMEM;
+
+ priv = peci_get_adapdata(adapter);
+ priv->adapter = adapter;
+ priv->dev = &pdev->dev;
+ dev_set_drvdata(&pdev->dev, priv);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(base)) {
+ ret = PTR_ERR(base);
+ goto err_put_adapter_dev;
+ }
+
+ priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+ &aspeed_peci_regmap_config);
+ if (IS_ERR(priv->regmap)) {
+ ret = PTR_ERR(priv->regmap);
+ goto err_put_adapter_dev;
+ }
+
+ /**
+ * We check that the regmap works on this very first access,
+ * but as this is an MMIO-backed regmap, subsequent regmap
+ * access is not going to fail and we skip error checks from
+ * this point.
+ */
+ ret = regmap_read(priv->regmap, ASPEED_PECI_CMD, &cmd_sts);
+ if (ret) {
+ ret = -EIO;
+ goto err_put_adapter_dev;
+ }
+
+ priv->irq = platform_get_irq(pdev, 0);
+ if (!priv->irq) {
+ ret = -ENODEV;
+ goto err_put_adapter_dev;
+ }
+
+ ret = devm_request_irq(&pdev->dev, priv->irq, aspeed_peci_irq_handler,
+ 0, "peci-aspeed-irq", priv);
+ if (ret)
+ goto err_put_adapter_dev;
+
+ init_completion(&priv->xfer_complete);
+ spin_lock_init(&priv->lock);
+
+ priv->adapter->owner = THIS_MODULE;
+ priv->adapter->dev.of_node = of_node_get(dev_of_node(priv->dev));
+ strlcpy(priv->adapter->name, pdev->name, sizeof(priv->adapter->name));
+ priv->adapter->xfer = aspeed_peci_xfer;
+
+ priv->rst = devm_reset_control_get(&pdev->dev, NULL);
+ if (IS_ERR(priv->rst)) {
+ dev_err(&pdev->dev,
+ "missing or invalid reset controller entry");
+ ret = PTR_ERR(priv->rst);
+ goto err_put_adapter_dev;
+ }
+ reset_control_deassert(priv->rst);
+
+ ret = aspeed_peci_init_ctrl(priv);
+ if (ret)
+ goto err_put_adapter_dev;
+
+ ret = peci_add_adapter(priv->adapter);
+ if (ret)
+ goto err_put_adapter_dev;
+
+ dev_info(&pdev->dev, "peci bus %d registered, irq %d\n",
+ priv->adapter->nr, priv->irq);
+
+ return 0;
+
+err_put_adapter_dev:
+ put_device(&adapter->dev);
+ return ret;
+}
+
+static int aspeed_peci_remove(struct platform_device *pdev)
+{
+ struct aspeed_peci *priv = dev_get_drvdata(&pdev->dev);
+
+ reset_control_assert(priv->rst);
+ peci_del_adapter(priv->adapter);
+ of_node_put(priv->adapter->dev.of_node);
+
+ return 0;
+}
+
+static const struct of_device_id aspeed_peci_of_table[] = {
+ { .compatible = "aspeed,ast2400-peci", },
+ { .compatible = "aspeed,ast2500-peci", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, aspeed_peci_of_table);
+
+static struct platform_driver aspeed_peci_driver = {
+ .probe = aspeed_peci_probe,
+ .remove = aspeed_peci_remove,
+ .driver = {
+ .name = "peci-aspeed",
+ .of_match_table = of_match_ptr(aspeed_peci_of_table),
+ },
+};
+module_platform_driver(aspeed_peci_driver);
+
+MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
+MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
+MODULE_DESCRIPTION("ASPEED PECI driver");
+MODULE_LICENSE("GPL v2");