[PATCH v11 09/14] peci: npcm: add NPCM PECI driver
Jae Hyun Yoo
jae.hyun.yoo at linux.intel.com
Thu Dec 12 06:46:19 AEDT 2019
From: Tomer Maimon <tmaimon77 at gmail.com>
Add support for the Nuvoton NPCM BMC hardware to the Platform
Environment Control Interface (PECI) subsystem.
Signed-off-by: Tomer Maimon <tmaimon77 at gmail.com>
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo at linux.intel.com>
---
Changes since v10:
- Newly added in v11Split out peci-dev module from peci-core module.
drivers/peci/busses/Kconfig | 13 +
drivers/peci/busses/Makefile | 1 +
drivers/peci/busses/peci-npcm.c | 407 ++++++++++++++++++++++++++++++++
3 files changed, 421 insertions(+)
create mode 100644 drivers/peci/busses/peci-npcm.c
diff --git a/drivers/peci/busses/Kconfig b/drivers/peci/busses/Kconfig
index 2b2540221b36..bfacafb7a7ba 100644
--- a/drivers/peci/busses/Kconfig
+++ b/drivers/peci/busses/Kconfig
@@ -16,4 +16,17 @@ config PECI_ASPEED
This support is also available as a module. If so, the module
will be called peci-aspeed.
+config PECI_NPCM
+ tristate "Nuvoton NPCM PECI support"
+ select REGMAP_MMIO
+ depends on OF
+ depends on ARCH_NPCM || COMPILE_TEST
+ depends on PECI
+ help
+ Say Y here if you want support for the Platform Environment Control
+ Interface (PECI) bus adapter driver on the Nuvoton NPCM SoCs.
+
+ This support is also available as a module. If so, the module
+ will be called peci-npcm.
+
endmenu
diff --git a/drivers/peci/busses/Makefile b/drivers/peci/busses/Makefile
index 69e31dfaca19..aa8ce3ae5947 100644
--- a/drivers/peci/busses/Makefile
+++ b/drivers/peci/busses/Makefile
@@ -4,3 +4,4 @@
#
obj-$(CONFIG_PECI_ASPEED) += peci-aspeed.o
+obj-$(CONFIG_PECI_NPCM) += peci-npcm.o
diff --git a/drivers/peci/busses/peci-npcm.c b/drivers/peci/busses/peci-npcm.c
new file mode 100644
index 000000000000..36d061e6e53d
--- /dev/null
+++ b/drivers/peci/busses/peci-npcm.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Nuvoton Technology 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/mfd/syscon.h>
+#include <linux/reset.h>
+
+/* NPCM7xx GCR module */
+#define NPCM7XX_INTCR3_OFFSET 0x9C
+#define NPCM7XX_INTCR3_PECIVSEL BIT(19)
+
+/* NPCM PECI Registers */
+#define NPCM_PECI_CTL_STS 0x00
+#define NPCM_PECI_RD_LENGTH 0x04
+#define NPCM_PECI_ADDR 0x08
+#define NPCM_PECI_CMD 0x0C
+#define NPCM_PECI_CTL2 0x10
+#define NPCM_PECI_WR_LENGTH 0x1C
+#define NPCM_PECI_PDDR 0x2C
+#define NPCM_PECI_DAT_INOUT(n) (0x100 + ((n) * 4))
+
+#define NPCM_PECI_MAX_REG 0x200
+
+/* NPCM_PECI_CTL_STS - 0x00 : Control Register */
+#define NPCM_PECI_CTRL_DONE_INT_EN BIT(6)
+#define NPCM_PECI_CTRL_ABRT_ERR BIT(4)
+#define NPCM_PECI_CTRL_CRC_ERR BIT(3)
+#define NPCM_PECI_CTRL_DONE BIT(1)
+#define NPCM_PECI_CTRL_START_BUSY BIT(0)
+
+/* NPCM_PECI_RD_LENGTH - 0x04 : Command Register */
+#define NPCM_PECI_RD_LEN_MASK GENMASK(6, 0)
+
+/* NPCM_PECI_CMD - 0x10 : Command Register */
+#define NPCM_PECI_CTL2_MASK GENMASK(7, 6)
+
+/* NPCM_PECI_WR_LENGTH - 0x1C : Command Register */
+#define NPCM_PECI_WR_LEN_MASK GENMASK(6, 0)
+
+/* NPCM_PECI_PDDR - 0x2C : Command Register */
+#define NPCM_PECI_PDDR_MASK GENMASK(4, 0)
+
+#define NPCM_PECI_INT_MASK (NPCM_PECI_CTRL_ABRT_ERR | \
+ NPCM_PECI_CTRL_CRC_ERR | \
+ NPCM_PECI_CTRL_DONE)
+
+#define NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC 50000
+#define NPCM_PECI_IDLE_CHECK_INTERVAL_USEC 10000
+#define NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT 1000
+#define NPCM_PECI_CMD_TIMEOUT_MS_MAX 60000
+#define NPCM_PECI_HOST_NEG_BIT_RATE_MAX 31
+#define NPCM_PECI_HOST_NEG_BIT_RATE_MIN 7
+#define NPCM_PECI_HOST_NEG_BIT_RATE_DEFAULT 15
+#define NPCM_PECI_PULL_DOWN_DEFAULT 0
+#define NPCM_PECI_PULL_DOWN_MAX 2
+
+struct npcm_peci {
+ u32 cmd_timeout_ms;
+ u32 host_bit_rate;
+ struct completion xfer_complete;
+ struct regmap *gcr_regmap;
+ struct peci_adapter *adapter;
+ struct regmap *regmap;
+ u32 status;
+ spinlock_t lock; /* to sync completion status handling */
+ struct device *dev;
+ struct clk *clk;
+ int irq;
+};
+
+static int npcm_peci_xfer_native(struct npcm_peci *priv,
+ struct peci_xfer_msg *msg)
+{
+ long err, timeout = msecs_to_jiffies(priv->cmd_timeout_ms);
+ unsigned long flags;
+ unsigned int msg_rd;
+ u32 cmd_sts;
+ int i, rc;
+
+ /* Check command sts and bus idle state */
+ rc = regmap_read_poll_timeout(priv->regmap, NPCM_PECI_CTL_STS, cmd_sts,
+ !(cmd_sts & NPCM_PECI_CTRL_START_BUSY),
+ NPCM_PECI_IDLE_CHECK_INTERVAL_USEC,
+ NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC);
+ if (rc)
+ return rc; /* -ETIMEDOUT */
+
+ spin_lock_irqsave(&priv->lock, flags);
+ reinit_completion(&priv->xfer_complete);
+
+ regmap_write(priv->regmap, NPCM_PECI_ADDR, msg->addr);
+ regmap_write(priv->regmap, NPCM_PECI_RD_LENGTH,
+ NPCM_PECI_WR_LEN_MASK & msg->rx_len);
+ regmap_write(priv->regmap, NPCM_PECI_WR_LENGTH,
+ NPCM_PECI_WR_LEN_MASK & msg->tx_len);
+
+ if (msg->tx_len) {
+ regmap_write(priv->regmap, NPCM_PECI_CMD, msg->tx_buf[0]);
+
+ for (i = 0; i < (msg->tx_len - 1); i++)
+ regmap_write(priv->regmap, NPCM_PECI_DAT_INOUT(i),
+ msg->tx_buf[i + 1]);
+ }
+
+ priv->status = 0;
+ regmap_update_bits(priv->regmap, NPCM_PECI_CTL_STS,
+ NPCM_PECI_CTRL_START_BUSY,
+ NPCM_PECI_CTRL_START_BUSY);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ err = wait_for_completion_interruptible_timeout(&priv->xfer_complete,
+ timeout);
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ regmap_write(priv->regmap, NPCM_PECI_CMD, 0);
+
+ if (err <= 0 || priv->status != NPCM_PECI_CTRL_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;
+ }
+
+ for (i = 0; i < msg->rx_len; i++) {
+ regmap_read(priv->regmap, NPCM_PECI_DAT_INOUT(i), &msg_rd);
+ msg->rx_buf[i] = (u8)msg_rd;
+ }
+
+err_irqrestore:
+ spin_unlock_irqrestore(&priv->lock, flags);
+ return rc;
+}
+
+static irqreturn_t npcm_peci_irq_handler(int irq, void *arg)
+{
+ struct npcm_peci *priv = arg;
+ u32 status_ack = 0;
+ u32 status;
+
+ spin_lock(&priv->lock);
+ regmap_read(priv->regmap, NPCM_PECI_CTL_STS, &status);
+ priv->status |= (status & NPCM_PECI_INT_MASK);
+
+ if (status & NPCM_PECI_CTRL_CRC_ERR) {
+ dev_dbg(priv->dev, "PECI_INT_W_FCS_BAD\n");
+ status_ack |= NPCM_PECI_CTRL_CRC_ERR;
+ }
+
+ if (status & NPCM_PECI_CTRL_ABRT_ERR) {
+ dev_dbg(priv->dev, "NPCM_PECI_CTRL_ABRT_ERR\n");
+ status_ack |= NPCM_PECI_CTRL_ABRT_ERR;
+ }
+
+ /*
+ * All commands should be ended up with a NPCM_PECI_CTRL_DONE
+ * bit set even in an error case.
+ */
+ if (status & NPCM_PECI_CTRL_DONE) {
+ dev_dbg(priv->dev, "NPCM_PECI_CTRL_DONE\n");
+ status_ack |= NPCM_PECI_CTRL_DONE;
+ complete(&priv->xfer_complete);
+ }
+
+ regmap_write_bits(priv->regmap, NPCM_PECI_CTL_STS,
+ NPCM_PECI_INT_MASK, status_ack);
+
+ spin_unlock(&priv->lock);
+ return IRQ_HANDLED;
+}
+
+static int npcm_peci_init_ctrl(struct npcm_peci *priv)
+{
+ u32 cmd_sts, host_neg_bit_rate = 0, pull_down = 0;
+ int ret;
+
+ priv->clk = devm_clk_get(priv->dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ dev_err(priv->dev, "Failed to get clk source.\n");
+ return PTR_ERR(priv->clk);
+ }
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret) {
+ dev_err(priv->dev, "Failed to enable clock.\n");
+ return ret;
+ }
+
+ ret = of_property_read_u32(priv->dev->of_node, "cmd-timeout-ms",
+ &priv->cmd_timeout_ms);
+ if (ret || priv->cmd_timeout_ms > NPCM_PECI_CMD_TIMEOUT_MS_MAX ||
+ priv->cmd_timeout_ms == 0) {
+ if (ret)
+ dev_warn(priv->dev,
+ "cmd-timeout-ms not found, use default : %u\n",
+ NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT);
+ else
+ dev_warn(priv->dev,
+ "Invalid cmd-timeout-ms : %u. Use default : %u\n",
+ priv->cmd_timeout_ms,
+ NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT);
+
+ priv->cmd_timeout_ms = NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT;
+ }
+
+ if (of_device_is_compatible(priv->dev->of_node,
+ "nuvoton,npcm750-peci")) {
+ priv->gcr_regmap = syscon_regmap_lookup_by_compatible
+ ("nuvoton,npcm750-gcr");
+ if (!IS_ERR(priv->gcr_regmap)) {
+ bool volt = of_property_read_bool(priv->dev->of_node,
+ "high-volt-range");
+ if (volt)
+ regmap_update_bits(priv->gcr_regmap,
+ NPCM7XX_INTCR3_OFFSET,
+ NPCM7XX_INTCR3_PECIVSEL,
+ NPCM7XX_INTCR3_PECIVSEL);
+ else
+ regmap_update_bits(priv->gcr_regmap,
+ NPCM7XX_INTCR3_OFFSET,
+ NPCM7XX_INTCR3_PECIVSEL, 0);
+ }
+ }
+
+ ret = of_property_read_u32(priv->dev->of_node, "pull-down",
+ &pull_down);
+ if (ret || pull_down > NPCM_PECI_PULL_DOWN_MAX) {
+ if (ret)
+ dev_warn(priv->dev,
+ "pull-down not found, use default : %u\n",
+ NPCM_PECI_PULL_DOWN_DEFAULT);
+ else
+ dev_warn(priv->dev,
+ "Invalid pull-down : %u. Use default : %u\n",
+ pull_down,
+ NPCM_PECI_PULL_DOWN_DEFAULT);
+ pull_down = NPCM_PECI_PULL_DOWN_DEFAULT;
+ }
+
+ regmap_update_bits(priv->regmap, NPCM_PECI_CTL2, NPCM_PECI_CTL2_MASK,
+ pull_down << 6);
+
+ ret = of_property_read_u32(priv->dev->of_node, "host-neg-bit-rate",
+ &host_neg_bit_rate);
+ if (ret || host_neg_bit_rate > NPCM_PECI_HOST_NEG_BIT_RATE_MAX ||
+ host_neg_bit_rate < NPCM_PECI_HOST_NEG_BIT_RATE_MIN) {
+ if (ret)
+ dev_warn(priv->dev,
+ "host-neg-bit-rate not found, use default : %u\n",
+ NPCM_PECI_HOST_NEG_BIT_RATE_DEFAULT);
+ else
+ dev_warn(priv->dev,
+ "Invalid host-neg-bit-rate : %u. Use default : %u\n",
+ host_neg_bit_rate,
+ NPCM_PECI_HOST_NEG_BIT_RATE_DEFAULT);
+ host_neg_bit_rate = NPCM_PECI_HOST_NEG_BIT_RATE_DEFAULT;
+ }
+
+ regmap_update_bits(priv->regmap, NPCM_PECI_PDDR, NPCM_PECI_PDDR_MASK,
+ host_neg_bit_rate);
+
+ priv->host_bit_rate = clk_get_rate(priv->clk) /
+ (4 * (host_neg_bit_rate + 1));
+
+ ret = regmap_read_poll_timeout(priv->regmap, NPCM_PECI_CTL_STS, cmd_sts,
+ !(cmd_sts & NPCM_PECI_CTRL_START_BUSY),
+ NPCM_PECI_IDLE_CHECK_INTERVAL_USEC,
+ NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC);
+ if (ret)
+ return ret; /* -ETIMEDOUT */
+
+ /* PECI interrupt enable */
+ regmap_update_bits(priv->regmap, NPCM_PECI_CTL_STS,
+ NPCM_PECI_CTRL_DONE_INT_EN,
+ NPCM_PECI_CTRL_DONE_INT_EN);
+
+ return 0;
+}
+
+static const struct regmap_config npcm_peci_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = NPCM_PECI_MAX_REG,
+ .fast_io = true,
+};
+
+static int npcm_peci_xfer(struct peci_adapter *adapter,
+ struct peci_xfer_msg *msg)
+{
+ struct npcm_peci *priv = peci_get_adapdata(adapter);
+
+ return npcm_peci_xfer_native(priv, msg);
+}
+
+static int npcm_peci_probe(struct platform_device *pdev)
+{
+ struct peci_adapter *adapter;
+ struct npcm_peci *priv;
+ void __iomem *base;
+ 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);
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base)) {
+ ret = PTR_ERR(base);
+ goto err_put_adapter_dev;
+ }
+
+ priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+ &npcm_peci_regmap_config);
+ if (IS_ERR(priv->regmap)) {
+ ret = PTR_ERR(priv->regmap);
+ 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, npcm_peci_irq_handler,
+ 0, "peci-npcm-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 = npcm_peci_xfer;
+
+ ret = npcm_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, host negotiation bit rate %dHz",
+ priv->adapter->nr, priv->host_bit_rate);
+
+ return 0;
+
+err_put_adapter_dev:
+ put_device(&adapter->dev);
+ return ret;
+}
+
+static int npcm_peci_remove(struct platform_device *pdev)
+{
+ struct npcm_peci *priv = dev_get_drvdata(&pdev->dev);
+
+ clk_disable_unprepare(priv->clk);
+ peci_del_adapter(priv->adapter);
+ of_node_put(priv->adapter->dev.of_node);
+
+ return 0;
+}
+
+static const struct of_device_id npcm_peci_of_table[] = {
+ { .compatible = "nuvoton,npcm750-peci", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, npcm_peci_of_table);
+
+static struct platform_driver npcm_peci_driver = {
+ .probe = npcm_peci_probe,
+ .remove = npcm_peci_remove,
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = of_match_ptr(npcm_peci_of_table),
+ },
+};
+module_platform_driver(npcm_peci_driver);
+
+MODULE_AUTHOR("Tomer Maimon <tomer.maimon at nuvoton.com>");
+MODULE_DESCRIPTION("NPCM Platform Environment Control Interface (PECI) driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1
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