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Commit d1c244f3 authored by Rajesh Kemisetti's avatar Rajesh Kemisetti Committed by samit vats
Browse files

soc: qcom: Add support for Cx iPeak limit driver 



Implement common driver to limit Cx ipeak based on
voting from various clients in multimedia.

Change-Id: Ie0a57e49f7a8ba8a4fa3aa7f50dd0947f8e9d11b
Signed-off-by: default avatarRajesh Kemisetti <rajeshk@codeaurora.org>
Signed-off-by: default avatarsamit vats <svats@codeaurora.org>
parent ad1e28d6

Documentation/devicetree/bindings/soc/qcom/qcom,cx_ipeak.txt

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* Cx iPeak driver to handle requests from various multimedia clients.



Cx ipeak HW module is used to limit the current drawn by various subsystem

blocks on Cx power rail. Each client needs to set their

bit in tcsr register if it is going to cross its own threshold. If all

clients are going to cross their thresholds then Cx ipeak hw module will raise

an interrupt to cDSP block to throttle cDSP's fmax.



Required properties:



- compatible : name of the component used for driver matching, should be

	       "qcom,cx-ipeak-sdm660"



- reg : physical base address and length of the register set(s), SRAM and XPU

	of the component.



Example:



	cx_ipeak_lm: cx_ipeak@1fe5040 {

		compatible = "qcom,cx-ipeak-sdm660";

		reg = <0x01fe5040 0x28>;

	};

drivers/soc/qcom/Kconfig

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@@ -787,4 +787,13 @@ config QCOM_CDSP_RM 
	  improving CDSP performance. Using this driver, CDSP can set appropriate

	  CPU L3 clock for improving IO-Coherent throughput and opt for QoS mode

	  to improve RPC latency.



config QCOM_CX_IPEAK

	bool "Common driver to handle Cx iPeak limitation"

	help

	  Cx ipeak HW module is used to limit the current drawn by various subsystem

	  blocks on Cx power rail. Each client needs to set their

	  bit in tcsr register if it is going to cross its own threshold. If all

	  clients are going to cross their thresholds then Cx ipeak hw module will raise

	  an interrupt to cDSP block to throttle cDSP fmax.

endmenu

drivers/soc/qcom/Makefile

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@@ -92,3 +92,4 @@ endif 
obj-$(CONFIG_QCOM_SMP2P_SLEEPSTATE) += smp2p_sleepstate.o

obj-$(CONFIG_QCOM_MEM_OFFLINE) += mem-offline.o

obj-$(CONFIG_QCOM_CDSP_RM) += cdsprm.o

obj-$(CONFIG_QCOM_CX_IPEAK) += cx_ipeak.o

drivers/soc/qcom/cx_ipeak.c

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/* Copyright (c) 2018, 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);

include/soc/qcom/cx_ipeak.h

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/* Copyright (c) 2018, 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.

 */



#ifndef __SOC_COM_CX_IPEAK_H

#define __SOC_COM_CX_IPEAK_H



struct device_node;

struct cx_ipeak_client;



#ifndef CONFIG_QCOM_CX_IPEAK



static inline struct cx_ipeak_client *cx_ipeak_register(

		struct device_node *dev_node,

		const char *client_name)

{

	return NULL;

}



static inline void cx_ipeak_unregister(struct cx_ipeak_client *client)

{

}



static inline int cx_ipeak_update(struct cx_ipeak_client *ipeak_client,

			bool vote)

{

	return 0;

}

#else



struct cx_ipeak_client *cx_ipeak_register(struct device_node *dev_node,

		const char *client_name);

void cx_ipeak_unregister(struct cx_ipeak_client *client);

int cx_ipeak_update(struct cx_ipeak_client *ipeak_client, bool vote);



#endif



#endif /*__SOC_COM_CX_IPEAK_H*/