diff options
Diffstat (limited to 'drivers/soc/qcom/qcom-pbs.c')
| -rw-r--r-- | drivers/soc/qcom/qcom-pbs.c | 236 |
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 000000000000..6af49b5060e5 --- /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"); |