summaryrefslogtreecommitdiffstats
path: root/drivers/soc/qcom/qcom-pbs.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/soc/qcom/qcom-pbs.c')
-rw-r--r--drivers/soc/qcom/qcom-pbs.c236
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/soc/qcom/qcom-pbs.c b/drivers/soc/qcom/qcom-pbs.c
new file mode 100644
index 0000000000..6af49b5060
--- /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");