soc: qcom: add QCOM PBS driver

Add the Qualcomm PBS (Programmable Boot Sequencer) driver. The QCOM PBS
driver supports configuring software PBS trigger events through PBS RAM
on Qualcomm Technologies, Inc (QTI) PMICs.

Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.com>
Link: https://lore.kernel.org/r/20240201204421.16992-6-quic_amelende@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index c6ca4de425863dd42c6482104ce13f431027c32d..5af33b0e3470ec4e9d5b3242fb9755e94ecbd2df 100644 (file)
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -268,4 +268,13 @@ config QCOM_INLINE_CRYPTO_ENGINE
        tristate
        select QCOM_SCM
 
+config QCOM_PBS
+       tristate "PBS trigger support for Qualcomm Technologies, Inc. PMICS"
+       depends on SPMI
+       help
+         This driver supports configuring software programmable boot sequencer (PBS)
+         trigger event through PBS RAM on Qualcomm Technologies, Inc. PMICs.
+         This module provides the APIs to the client drivers that wants to send the
+         PBS trigger event to the PBS RAM.
+
 endmenu

diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 05b3d54e8dc93992d3bbce0e1eca0d7fa964cd69..0a419b458fb2c4d0737ee0f1e4cb6b61cb9a50ec 100644 (file)
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -34,3 +34,4 @@ obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=       kryo-l2-accessors.o
 obj-$(CONFIG_QCOM_ICC_BWMON)   += icc-bwmon.o
 qcom_ice-objs                  += ice.o
 obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)        += qcom_ice.o
+obj-$(CONFIG_QCOM_PBS) +=      qcom-pbs.o

diff --git a/drivers/soc/qcom/qcom-pbs.c b/drivers/soc/qcom/qcom-pbs.c
new file mode 100644 (file)
index 0000000..6af49b5
--- /dev/null
+++ b/drivers/soc/qcom/qcom-pbs.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/spmi.h>
+#include <linux/soc/qcom/qcom-pbs.h>
+
+#define PBS_CLIENT_TRIG_CTL            0x42
+#define PBS_CLIENT_SW_TRIG_BIT         BIT(7)
+#define PBS_CLIENT_SCRATCH1            0x50
+#define PBS_CLIENT_SCRATCH2            0x51
+#define PBS_CLIENT_SCRATCH2_ERROR      0xFF
+
+#define RETRIES                                2000
+#define DELAY                          1100
+
+struct pbs_dev {
+       struct device           *dev;
+       struct regmap           *regmap;
+       struct mutex            lock;
+       struct device_link      *link;
+
+       u32                     base;
+};
+
+static int qcom_pbs_wait_for_ack(struct pbs_dev *pbs, u8 bit_pos)
+{
+       unsigned int val;
+       int ret;
+
+       ret = regmap_read_poll_timeout(pbs->regmap,  pbs->base + PBS_CLIENT_SCRATCH2,
+                                      val, val & BIT(bit_pos), DELAY, DELAY * RETRIES);
+
+       if (ret < 0) {
+               dev_err(pbs->dev, "Timeout for PBS ACK/NACK for bit %u\n", bit_pos);
+               return -ETIMEDOUT;
+       }
+
+       if (val == PBS_CLIENT_SCRATCH2_ERROR) {
+               ret = regmap_write(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, 0);
+               dev_err(pbs->dev, "NACK from PBS for bit %u\n", bit_pos);
+               return -EINVAL;
+       }
+
+       dev_dbg(pbs->dev, "PBS sequence for bit %u executed!\n", bit_pos);
+       return 0;
+}
+
+/**
+ * qcom_pbs_trigger_event() - Trigger the PBS RAM sequence
+ * @pbs: Pointer to PBS device
+ * @bitmap: bitmap
+ *
+ * This function is used to trigger the PBS RAM sequence to be
+ * executed by the client driver.
+ *
+ * The PBS trigger sequence involves
+ * 1. setting the PBS sequence bit in PBS_CLIENT_SCRATCH1
+ * 2. Initiating the SW PBS trigger
+ * 3. Checking the equivalent bit in PBS_CLIENT_SCRATCH2 for the
+ *    completion of the sequence.
+ * 4. If PBS_CLIENT_SCRATCH2 == 0xFF, the PBS sequence failed to execute
+ *
+ * Return: 0 on success, < 0 on failure
+ */
+int qcom_pbs_trigger_event(struct pbs_dev *pbs, u8 bitmap)
+{
+       unsigned int val;
+       u16 bit_pos;
+       int ret;
+
+       if (WARN_ON(!bitmap))
+               return -EINVAL;
+
+       if (IS_ERR_OR_NULL(pbs))
+               return -EINVAL;
+
+       mutex_lock(&pbs->lock);
+       ret = regmap_read(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, &val);
+       if (ret < 0)
+               goto out;
+
+       if (val == PBS_CLIENT_SCRATCH2_ERROR) {
+               /* PBS error - clear SCRATCH2 register */
+               ret = regmap_write(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, 0);
+               if (ret < 0)
+                       goto out;
+       }
+
+       for (bit_pos = 0; bit_pos < 8; bit_pos++) {
+               if (!(bitmap & BIT(bit_pos)))
+                       continue;
+
+               /* Clear the PBS sequence bit position */
+               ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2,
+                                        BIT(bit_pos), 0);
+               if (ret < 0)
+                       goto out_clear_scratch1;
+
+               /* Set the PBS sequence bit position */
+               ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1,
+                                        BIT(bit_pos), BIT(bit_pos));
+               if (ret < 0)
+                       goto out_clear_scratch1;
+
+               /* Initiate the SW trigger */
+               ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_TRIG_CTL,
+                                        PBS_CLIENT_SW_TRIG_BIT, PBS_CLIENT_SW_TRIG_BIT);
+               if (ret < 0)
+                       goto out_clear_scratch1;
+
+               ret = qcom_pbs_wait_for_ack(pbs, bit_pos);
+               if (ret < 0)
+                       goto out_clear_scratch1;
+
+               /* Clear the PBS sequence bit position */
+               regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1, BIT(bit_pos), 0);
+               regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, BIT(bit_pos), 0);
+       }
+
+out_clear_scratch1:
+       /* Clear all the requested bitmap */
+       ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1, bitmap, 0);
+
+out:
+       mutex_unlock(&pbs->lock);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(qcom_pbs_trigger_event);
+
+/**
+ * get_pbs_client_device() - Get the PBS device used by client
+ * @dev: Client device
+ *
+ * This function is used to get the PBS device that is being
+ * used by the client.
+ *
+ * Return: pbs_dev on success, ERR_PTR on failure
+ */
+struct pbs_dev *get_pbs_client_device(struct device *dev)
+{
+       struct device_node *pbs_dev_node;
+       struct platform_device *pdev;
+       struct pbs_dev *pbs;
+
+       pbs_dev_node = of_parse_phandle(dev->of_node, "qcom,pbs", 0);
+       if (!pbs_dev_node) {
+               dev_err(dev, "Missing qcom,pbs property\n");
+               return ERR_PTR(-ENODEV);
+       }
+
+       pdev = of_find_device_by_node(pbs_dev_node);
+       if (!pdev) {
+               dev_err(dev, "Unable to find PBS dev_node\n");
+               pbs = ERR_PTR(-EPROBE_DEFER);
+               goto out;
+       }
+
+       pbs = platform_get_drvdata(pdev);
+       if (!pbs) {
+               dev_err(dev, "Cannot get pbs instance from %s\n", dev_name(&pdev->dev));
+               platform_device_put(pdev);
+               pbs = ERR_PTR(-EPROBE_DEFER);
+               goto out;
+       }
+
+       pbs->link = device_link_add(dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER);
+       if (!pbs->link) {
+               dev_err(&pdev->dev, "Failed to create device link to consumer %s\n", dev_name(dev));
+               platform_device_put(pdev);
+               pbs = ERR_PTR(-EINVAL);
+               goto out;
+       }
+
+out:
+       of_node_put(pbs_dev_node);
+       return pbs;
+}
+EXPORT_SYMBOL_GPL(get_pbs_client_device);
+
+static int qcom_pbs_probe(struct platform_device *pdev)
+{
+       struct pbs_dev *pbs;
+       u32 val;
+       int ret;
+
+       pbs = devm_kzalloc(&pdev->dev, sizeof(*pbs), GFP_KERNEL);
+       if (!pbs)
+               return -ENOMEM;
+
+       pbs->dev = &pdev->dev;
+       pbs->regmap = dev_get_regmap(pbs->dev->parent, NULL);
+       if (!pbs->regmap) {
+               dev_err(pbs->dev, "Couldn't get parent's regmap\n");
+               return -EINVAL;
+       }
+
+       ret = device_property_read_u32(pbs->dev, "reg", &val);
+       if (ret < 0) {
+               dev_err(pbs->dev, "Couldn't find reg, ret = %d\n", ret);
+               return ret;
+       }
+       pbs->base = val;
+       mutex_init(&pbs->lock);
+
+       platform_set_drvdata(pdev, pbs);
+
+       return 0;
+}
+
+static const struct of_device_id qcom_pbs_match_table[] = {
+       { .compatible = "qcom,pbs" },
+       {}
+};
+MODULE_DEVICE_TABLE(of, qcom_pbs_match_table);
+
+static struct platform_driver qcom_pbs_driver = {
+       .driver = {
+               .name           = "qcom-pbs",
+               .of_match_table = qcom_pbs_match_table,
+       },
+       .probe = qcom_pbs_probe,
+};
+module_platform_driver(qcom_pbs_driver)
+
+MODULE_DESCRIPTION("QCOM PBS DRIVER");
+MODULE_LICENSE("GPL");

diff --git a/include/linux/soc/qcom/qcom-pbs.h b/include/linux/soc/qcom/qcom-pbs.h
new file mode 100644 (file)
index 0000000..8a46209
--- /dev/null
+++ b/include/linux/soc/qcom/qcom-pbs.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#ifndef _QCOM_PBS_H
+#define _QCOM_PBS_H
+
+#include <linux/errno.h>
+#include <linux/types.h>
+
+struct device_node;
+struct pbs_dev;
+
+#if IS_ENABLED(CONFIG_QCOM_PBS)
+int qcom_pbs_trigger_event(struct pbs_dev *pbs, u8 bitmap);
+struct pbs_dev *get_pbs_client_device(struct device *client_dev);
+#else
+static inline int qcom_pbs_trigger_event(struct pbs_dev *pbs, u8 bitmap)
+{
+       return -ENODEV;
+}
+
+static inline struct pbs_dev *get_pbs_client_device(struct device *client_dev)
+{
+       return ERR_PTR(-ENODEV);
+}
+#endif
+
+#endif