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/* Copyright (c) 2016-2017, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/module.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/printk.h>
#include <linux/spinlock.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <soc/qcom/cx_ipeak.h>
#define TCSR_CXIP_LM_VOTE_BYPASS_OFFSET 0x4
#define TCSR_CXIP_LM_VOTE_CLEAR_OFFSET 0x8
#define TCSR_CXIP_LM_VOTE_SET_OFFSET 0xC
#define TCSR_CXIP_LM_VOTE_FEATURE_ENABLE_OFFSET 0x10
#define TCSR_CXIP_LM_TRS_OFFSET 0x24
#define CXIP_POLL_TIMEOUT_US (50 * 1000)
static struct cx_ipeak_device {
spinlock_t vote_lock;
void __iomem *tcsr_vptr;
} device_ipeak;
struct cx_ipeak_client {
int vote_count;
unsigned int vote_mask;
struct cx_ipeak_device *dev;
};
/**
* cx_ipeak_register() - allocate client structure and fill device private and
* bit details.
* @dev_node: device node of the client
* @client_name: property name of the client
*
* Allocate client memory and fill the structure with device private and bit
*
*/
struct cx_ipeak_client *cx_ipeak_register(struct device_node *dev_node,
const char *client_name)
{
struct of_phandle_args cx_spec;
struct cx_ipeak_client *client;
unsigned int reg_enable, reg_bypass;
int ret;
ret = of_parse_phandle_with_fixed_args(dev_node, client_name,
1, 0, &cx_spec);
if (ret)
return ERR_PTR(-EINVAL);
if (!of_device_is_available(cx_spec.np))
return NULL;
if (device_ipeak.tcsr_vptr == NULL)
return ERR_PTR(-EPROBE_DEFER);
if (cx_spec.args[0] > 31)
return ERR_PTR(-EINVAL);
reg_enable = readl_relaxed(device_ipeak.tcsr_vptr +
TCSR_CXIP_LM_VOTE_FEATURE_ENABLE_OFFSET);
reg_bypass = readl_relaxed(device_ipeak.tcsr_vptr +
TCSR_CXIP_LM_VOTE_BYPASS_OFFSET) &
BIT(cx_spec.args[0]);
if (!reg_enable || reg_bypass)
return NULL;
client = kzalloc(sizeof(struct cx_ipeak_client), GFP_KERNEL);
if (!client)
return ERR_PTR(-ENOMEM);
client->vote_mask = BIT(cx_spec.args[0]);
client->dev = &device_ipeak;
return client;
}
EXPORT_SYMBOL(cx_ipeak_register);
/**
* cx_ipeak_unregister() - unregister client
* @client: client address to free
*
* Free the client memory
*/
void cx_ipeak_unregister(struct cx_ipeak_client *client)
{
kfree(client);
}
EXPORT_SYMBOL(cx_ipeak_unregister);
/*
* cx_ipeak_update() - Set/Clear client vote for Cx iPeak limit
* manager to throttle cDSP.
* @client: client handle.
* @vote: True to set the vote and False for reset.
*
* Receives vote from each client and decides whether to throttle cDSP or not.
* This function is NOP for the targets which does not support TCSR Cx iPeak.
*/
int cx_ipeak_update(struct cx_ipeak_client *client, bool vote)
{
unsigned int reg_val;
int ret = 0;
/* Check for client and device availability and proceed */
if (client == NULL || client->dev->tcsr_vptr == NULL)
return ret;
spin_lock(&client->dev->vote_lock);
if (vote) {
if (client->vote_count == 0) {
writel_relaxed(client->vote_mask,
client->dev->tcsr_vptr +
TCSR_CXIP_LM_VOTE_SET_OFFSET);
/*
* Do a dummy read to give enough time for TRS register
* to become 1 when the last client votes.
*/
readl_relaxed(client->dev->tcsr_vptr +
TCSR_CXIP_LM_TRS_OFFSET);
ret = readl_poll_timeout(client->dev->tcsr_vptr +
TCSR_CXIP_LM_TRS_OFFSET, reg_val, !reg_val,
0, CXIP_POLL_TIMEOUT_US);
if (ret) {
writel_relaxed(client->vote_mask,
client->dev->tcsr_vptr +
TCSR_CXIP_LM_VOTE_CLEAR_OFFSET);
goto done;
}
}
client->vote_count++;
} else {
if (client->vote_count > 0) {
client->vote_count--;
if (client->vote_count == 0) {
writel_relaxed(client->vote_mask,
client->dev->tcsr_vptr +
TCSR_CXIP_LM_VOTE_CLEAR_OFFSET);
}
} else
ret = -EINVAL;
}
done:
spin_unlock(&client->dev->vote_lock);
return ret;
}
EXPORT_SYMBOL(cx_ipeak_update);
static int cx_ipeak_probe(struct platform_device *pdev)
{
struct resource *res;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
device_ipeak.tcsr_vptr = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(device_ipeak.tcsr_vptr))
return PTR_ERR(device_ipeak.tcsr_vptr);
spin_lock_init(&device_ipeak.vote_lock);
return 0;
}
static const struct of_device_id cx_ipeak_match_table[] = {
{ .compatible = "qcom,cx-ipeak-sdm660"},
{}
};
static struct platform_driver cx_ipeak_platform_driver = {
.probe = cx_ipeak_probe,
.driver = {
.name = "cx_ipeak",
.of_match_table = cx_ipeak_match_table,
.suppress_bind_attrs = true,
}
};
static int __init cx_ipeak_init(void)
{
return platform_driver_register(&cx_ipeak_platform_driver);
}
arch_initcall(cx_ipeak_init);
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