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// 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");
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