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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 <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Bjorn Andersson <[email protected]>
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// SPDX-License-Identifier: GPL-2.0-only | ||
/* | ||
* Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved. | ||
*/ | ||
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#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> | ||
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#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 | ||
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#define RETRIES 2000 | ||
#define DELAY 1100 | ||
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struct pbs_dev { | ||
struct device *dev; | ||
struct regmap *regmap; | ||
struct mutex lock; | ||
struct device_link *link; | ||
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u32 base; | ||
}; | ||
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static int qcom_pbs_wait_for_ack(struct pbs_dev *pbs, u8 bit_pos) | ||
{ | ||
unsigned int val; | ||
int ret; | ||
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ret = regmap_read_poll_timeout(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, | ||
val, val & BIT(bit_pos), DELAY, DELAY * RETRIES); | ||
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if (ret < 0) { | ||
dev_err(pbs->dev, "Timeout for PBS ACK/NACK for bit %u\n", bit_pos); | ||
return -ETIMEDOUT; | ||
} | ||
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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; | ||
} | ||
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dev_dbg(pbs->dev, "PBS sequence for bit %u executed!\n", bit_pos); | ||
return 0; | ||
} | ||
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/** | ||
* 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; | ||
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if (WARN_ON(!bitmap)) | ||
return -EINVAL; | ||
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if (IS_ERR_OR_NULL(pbs)) | ||
return -EINVAL; | ||
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mutex_lock(&pbs->lock); | ||
ret = regmap_read(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH2, &val); | ||
if (ret < 0) | ||
goto out; | ||
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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; | ||
} | ||
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for (bit_pos = 0; bit_pos < 8; bit_pos++) { | ||
if (!(bitmap & BIT(bit_pos))) | ||
continue; | ||
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/* 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; | ||
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/* 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; | ||
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/* 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; | ||
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ret = qcom_pbs_wait_for_ack(pbs, bit_pos); | ||
if (ret < 0) | ||
goto out_clear_scratch1; | ||
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/* 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); | ||
} | ||
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out_clear_scratch1: | ||
/* Clear all the requested bitmap */ | ||
ret = regmap_update_bits(pbs->regmap, pbs->base + PBS_CLIENT_SCRATCH1, bitmap, 0); | ||
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out: | ||
mutex_unlock(&pbs->lock); | ||
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return ret; | ||
} | ||
EXPORT_SYMBOL_GPL(qcom_pbs_trigger_event); | ||
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/** | ||
* 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; | ||
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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); | ||
} | ||
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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; | ||
} | ||
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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; | ||
} | ||
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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; | ||
} | ||
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out: | ||
of_node_put(pbs_dev_node); | ||
return pbs; | ||
} | ||
EXPORT_SYMBOL_GPL(get_pbs_client_device); | ||
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static int qcom_pbs_probe(struct platform_device *pdev) | ||
{ | ||
struct pbs_dev *pbs; | ||
u32 val; | ||
int ret; | ||
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pbs = devm_kzalloc(&pdev->dev, sizeof(*pbs), GFP_KERNEL); | ||
if (!pbs) | ||
return -ENOMEM; | ||
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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; | ||
} | ||
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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); | ||
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platform_set_drvdata(pdev, pbs); | ||
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return 0; | ||
} | ||
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static const struct of_device_id qcom_pbs_match_table[] = { | ||
{ .compatible = "qcom,pbs" }, | ||
{} | ||
}; | ||
MODULE_DEVICE_TABLE(of, qcom_pbs_match_table); | ||
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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) | ||
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MODULE_DESCRIPTION("QCOM PBS DRIVER"); | ||
MODULE_LICENSE("GPL"); |
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/* SPDX-License-Identifier: GPL-2.0-only */ | ||
/* | ||
* Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved. | ||
*/ | ||
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#ifndef _QCOM_PBS_H | ||
#define _QCOM_PBS_H | ||
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#include <linux/errno.h> | ||
#include <linux/types.h> | ||
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struct device_node; | ||
struct pbs_dev; | ||
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#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; | ||
} | ||
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static inline struct pbs_dev *get_pbs_client_device(struct device *client_dev) | ||
{ | ||
return ERR_PTR(-ENODEV); | ||
} | ||
#endif | ||
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#endif |