msm: mdss: Add mdss display SPI client

Qualcomm Technologies, Inc. mdss-spi-client

mdss-spi-client is for SPI display to send the FB data to SPI master.

Required properties:

- compatible : should be "qcom,mdss-spi-client"

- spi-max-frequency : Maximum SPI clocking speed of device in Hz

Optional properties:

- label: A string used to describe the controller used.

- spi-cpol : Boolean property indicating device requires inverse

  clock polarity (CPOL) mode

- spi-cpha :  Empty property indicating device requires shifted

  clock phase (CPHA) mode

- spi-cs-high :  Empty property indicating device requires

  chip select active high

Example:

spi@78b9000 { /* BLSP1 QUP5 */

	qcom,mdss_spi_client {

		reg = <0>;

		compatible = "qcom,mdss-spi-client";

		label = "MDSS SPI QUP5 CLIENT";

		spi-max-frequency = <50000000>;

	};

};

/* Copyright (c) 2017-2018, 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/kernel.h>

#include <linux/spi/spi.h>

#include <linux/of_gpio.h>

#include <linux/gpio.h>

#include <linux/qpnp/pin.h>

#include <linux/delay.h>

#include "mdss_spi_client.h"

#define MAX_READ_SPEED_HZ	9600000

#define SPI_PANEL_COMMAND_LEN	1

static struct spi_device *mdss_spi_client;

int mdss_spi_read_data(u8 reg_addr, u8 *data, u8 len)

{

	int rc = 0;

	u32 max_speed_hz;

	u8 memory_write_reg = 0x2c;

	u8 empty_pack[] = {0x29, 0x29, 0x29};

	struct spi_transfer t[4] = {

		[0] = {

			.tx_buf = &reg_addr,

			.len = 1,

		},

		[1] = {

			.rx_buf = data,

			.len = len,

		},

		[2] = {

			.tx_buf = &empty_pack,

			.len = 3,

		},

		[3] = {

			.tx_buf = &memory_write_reg,

			.len = 1,

		}

	};

	struct spi_message m;

	if (!mdss_spi_client) {

		pr_err("%s: spi client not available\n", __func__);

		return -EINVAL;

	}

	mdss_spi_client->bits_per_word = 8;

	max_speed_hz = mdss_spi_client->max_speed_hz;

	mdss_spi_client->max_speed_hz = MAX_READ_SPEED_HZ;

	spi_message_init(&m);

	spi_message_add_tail(&t[0], &m);

	spi_message_add_tail(&t[1], &m);

	rc = spi_sync(mdss_spi_client, &m);

	spi_message_init(&m);

	spi_message_add_tail(&t[2], &m);

	rc = spi_sync(mdss_spi_client, &m);

	spi_message_init(&m);

	spi_message_add_tail(&t[3], &m);

	rc = spi_sync(mdss_spi_client, &m);

	mdss_spi_client->max_speed_hz = max_speed_hz;

	return rc;

}

int mdss_spi_tx_command(const void *buf)

{

	int rc = 0;

	struct spi_transfer t = {

		.tx_buf = buf,

		.len    = SPI_PANEL_COMMAND_LEN,

	};

	struct spi_message m;

	if (!mdss_spi_client) {

		pr_err("%s: spi client not available\n", __func__);

		return -EINVAL;

	}

	mdss_spi_client->bits_per_word = 8;

	spi_message_init(&m);

	spi_message_add_tail(&t, &m);

	rc = spi_sync(mdss_spi_client, &m);

	return rc;

}

int mdss_spi_tx_parameter(const void *buf, size_t len)

{

	int rc = 0;

	struct spi_transfer t = {

		.tx_buf = buf,

		.len    = len,

	};

	struct spi_message m;

	if (!mdss_spi_client) {

		pr_err("%s: spi client not available\n", __func__);

		return -EINVAL;

	}

	mdss_spi_client->bits_per_word = 8;

	spi_message_init(&m);

	spi_message_add_tail(&t, &m);

	rc = spi_sync(mdss_spi_client, &m);

	return rc;

}

int mdss_spi_tx_pixel(const void *buf, size_t len)

{

	int rc = 0;

	struct spi_transfer t = {

		.tx_buf = buf,

		.len    = len,

		};

	struct spi_message m;

	if (!mdss_spi_client) {

		pr_err("%s: spi client not available\n", __func__);

		return -EINVAL;

	}

	mdss_spi_client->bits_per_word = 16;

	spi_message_init(&m);

	spi_message_add_tail(&t, &m);

	rc = spi_sync(mdss_spi_client, &m);

	return rc;

}

static int mdss_spi_client_probe(struct spi_device *spidev)

{

	int irq;

	int cs;

	int cpha, cpol, cs_high;

	u32 max_speed;

	struct device_node *np;

	irq = spidev->irq;

	cs = spidev->chip_select;

	cpha = (spidev->mode & SPI_CPHA) ? 1:0;

	cpol = (spidev->mode & SPI_CPOL) ? 1:0;

	cs_high = (spidev->mode & SPI_CS_HIGH) ? 1:0;

	max_speed = spidev->max_speed_hz;

	np = spidev->dev.of_node;

	pr_debug("cs[%x] CPHA[%x] CPOL[%x] CS_HIGH[%x] Max_speed[%d]\n",

		cs, cpha, cpol, cs_high, max_speed);

	mdss_spi_client = spidev;

	return 0;

}

static const struct of_device_id mdss_spi_dt_match[] = {

	{ .compatible = "qcom,mdss-spi-client" },

	{},

};

static struct spi_driver mdss_spi_client_driver = {

	.probe = mdss_spi_client_probe,

	.driver = {

		.name = "mdss-spi-client",

		.owner  = THIS_MODULE,

		.of_match_table = mdss_spi_dt_match,

	},

};

static int __init mdss_spi_init(void)

{

	int ret;

	ret = spi_register_driver(&mdss_spi_client_driver);

	return 0;

}

module_init(mdss_spi_init);

static void __exit mdss_spi_exit(void)

{

	spi_unregister_driver(&mdss_spi_client_driver);

}

module_exit(mdss_spi_exit);

/* Copyright (c) 2017-2018, 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 __MDSS_SPI_CLINET_H__

#define __MDSS_SPI_CLINET_H__

int mdss_spi_tx_command(const void *buf);

int mdss_spi_tx_parameter(const void *buf, size_t len);

int mdss_spi_tx_pixel(const void *buf, size_t len);

int mdss_spi_read_data(u8 reg_addr, u8 *data, u8 len);

#endif /* End of __MDSS_SPI_CLINET_H__ */