tpm/st33zp24/spi: Remove nbr_dummy_bytes variable usage (604e5788) · Commits · jan.koester / Linux

drivers/char/tpm/st33zp24/spi.c

+72 −112

Original line number	Diff line number	Diff line
		/*
		* STMicroelectronics TPM SPI Linux driver for TPM ST33ZP24
		* Copyright (C) 2009 - 2016 STMicroelectronics
		* Copyright (C) 2009 - 2015 STMicroelectronics
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		@@ -19,10 +19,8 @@
		#include <linux/module.h>
		#include <linux/spi/spi.h>
		#include <linux/gpio.h>
		#include <linux/gpio/consumer.h>
		#include <linux/of_irq.h>
		#include <linux/of_gpio.h>
		#include <linux/acpi.h>
		#include <linux/tpm.h>
		#include <linux/platform_data/st33zp24.h>

		@@ -68,7 +66,7 @@

		struct st33zp24_spi_phy {
		struct spi_device *spi_device;

		struct spi_transfer spi_xfer;
		u8 tx_buf[ST33ZP24_SPI_BUFFER_SIZE];
		u8 rx_buf[ST33ZP24_SPI_BUFFER_SIZE];

		@@ -112,39 +110,42 @@ static int st33zp24_status_to_errno(u8 code)
		static int st33zp24_spi_send(void phy_id, u8 tpm_register, u8 tpm_data,
		int tpm_size)
		{
		u8 data = 0;
		int total_length = 0, ret = 0;
		struct st33zp24_spi_phy *phy = phy_id;
		struct spi_device *dev = phy->spi_device;
		struct spi_transfer spi_xfer = {
		.tx_buf = phy->tx_buf,
		.rx_buf = phy->rx_buf,
		};
		u8 tx_buf = (u8 )phy->spi_xfer.tx_buf;
		u8 *rx_buf = phy->spi_xfer.rx_buf;

		/* Pre-Header */
		phy->tx_buf[total_length++] = TPM_WRITE_DIRECTION \| LOCALITY0;
		phy->tx_buf[total_length++] = tpm_register;
		data = TPM_WRITE_DIRECTION \| LOCALITY0;
		memcpy(tx_buf + total_length, &data, sizeof(data));
		total_length++;
		data = tpm_register;
		memcpy(tx_buf + total_length, &data, sizeof(data));
		total_length++;

		if (tpm_size > 0 && tpm_register == TPM_DATA_FIFO) {
		phy->tx_buf[total_length++] = tpm_size >> 8;
		phy->tx_buf[total_length++] = tpm_size;
		tx_buf[total_length++] = tpm_size >> 8;
		tx_buf[total_length++] = tpm_size;
		}

		memcpy(&phy->tx_buf[total_length], tpm_data, tpm_size);
		memcpy(&tx_buf[total_length], tpm_data, tpm_size);
		total_length += tpm_size;

		memset(&phy->tx_buf[total_length], TPM_DUMMY_BYTE, phy->latency);
		memset(&tx_buf[total_length], TPM_DUMMY_BYTE, phy->latency);

		spi_xfer.len = total_length + phy->latency;
		phy->spi_xfer.len = total_length + phy->latency;

		ret = spi_sync_transfer(dev, &spi_xfer, 1);
		ret = spi_sync_transfer(dev, &phy->spi_xfer, 1);
		if (ret == 0)
		ret = phy->rx_buf[total_length + phy->latency - 1];
		ret = rx_buf[total_length + phy->latency - 1];

		return st33zp24_status_to_errno(ret);
		} /* st33zp24_spi_send() */

		/*
		* st33zp24_spi_read8_recv
		* read8_recv
		* Recv byte from the TIS register according to the ST33ZP24 SPI protocol.
		* @param: phy_id, the phy description
		* @param: tpm_register, the tpm tis register where the data should be read
		@@ -152,37 +153,39 @@ static int st33zp24_spi_send(void phy_id, u8 tpm_register, u8 tpm_data,
		* @param: tpm_size, tpm TPM response size to read.
		* @return: should be zero if success else a negative error code.
		*/
		static int st33zp24_spi_read8_reg(void phy_id, u8 tpm_register, u8 tpm_data,
		int tpm_size)
		static int read8_reg(void phy_id, u8 tpm_register, u8 tpm_data, int tpm_size)
		{
		u8 data = 0;
		int total_length = 0, ret;
		struct st33zp24_spi_phy *phy = phy_id;
		struct spi_device *dev = phy->spi_device;
		struct spi_transfer spi_xfer = {
		.tx_buf = phy->tx_buf,
		.rx_buf = phy->rx_buf,
		};
		u8 tx_buf = (u8 )phy->spi_xfer.tx_buf;
		u8 *rx_buf = phy->spi_xfer.rx_buf;

		/* Pre-Header */
		phy->tx_buf[total_length++] = LOCALITY0;
		phy->tx_buf[total_length++] = tpm_register;

		memset(&phy->tx_buf[total_length], TPM_DUMMY_BYTE,
		data = LOCALITY0;
		memcpy(tx_buf + total_length, &data, sizeof(data));
		total_length++;
		data = tpm_register;
		memcpy(tx_buf + total_length, &data, sizeof(data));
		total_length++;

		memset(&tx_buf[total_length], TPM_DUMMY_BYTE,
		phy->latency + tpm_size);

		spi_xfer.len = total_length + phy->latency + tpm_size;
		phy->spi_xfer.len = total_length + phy->latency + tpm_size;

		/* header + status byte + size of the data + status byte */
		ret = spi_sync_transfer(dev, &spi_xfer, 1);
		ret = spi_sync_transfer(dev, &phy->spi_xfer, 1);
		if (tpm_size > 0 && ret == 0) {
		ret = phy->rx_buf[total_length + phy->latency - 1];
		ret = rx_buf[total_length + phy->latency - 1];

		memcpy(tpm_data, phy->rx_buf + total_length + phy->latency,
		memcpy(tpm_data, rx_buf + total_length + phy->latency,
		tpm_size);
		}

		return ret;
		} /* st33zp24_spi_read8_reg() */
		} /* read8_reg() */

		/*
		* st33zp24_spi_recv
		@@ -198,13 +201,13 @@ static int st33zp24_spi_recv(void phy_id, u8 tpm_register, u8 tpm_data,
		{
		int ret;

		ret = st33zp24_spi_read8_reg(phy_id, tpm_register, tpm_data, tpm_size);
		ret = read8_reg(phy_id, tpm_register, tpm_data, tpm_size);
		if (!st33zp24_status_to_errno(ret))
		return tpm_size;
		return ret;
		} /* st33zp24_spi_recv() */

		static int st33zp24_spi_evaluate_latency(void *phy_id)
		static int evaluate_latency(void *phy_id)
		{
		struct st33zp24_spi_phy *phy = phy_id;
		int latency = 1, status = 0;
		@@ -212,15 +215,9 @@ static int st33zp24_spi_evaluate_latency(void *phy_id)

		while (!status && latency < MAX_SPI_LATENCY) {
		phy->latency = latency;
		status = st33zp24_spi_read8_reg(phy_id, TPM_INTF_CAPABILITY,
		&data, 1);
		status = read8_reg(phy_id, TPM_INTF_CAPABILITY, &data, 1);
		latency++;
		}
		if (status < 0)
		return status;
		if (latency == MAX_SPI_LATENCY)
		return -ENODEV;

		return latency - 1;
		} /* evaluate_latency() */

		@@ -229,59 +226,24 @@ static const struct st33zp24_phy_ops spi_phy_ops = {
		.recv = st33zp24_spi_recv,
		};

		static int st33zp24_spi_acpi_request_resources(struct spi_device *spi_dev)
		#ifdef CONFIG_OF
		static int tpm_stm_spi_of_request_resources(struct st33zp24_spi_phy *phy)
		{
		struct st33zp24_spi_phy *phy = spi_get_drvdata(spi_dev);
		const struct acpi_device_id *id;
		struct gpio_desc *gpiod_lpcpd;
		struct device *dev;

		if (!spi_dev)
		return -EINVAL;

		dev = &spi_dev->dev;

		/* Match the struct device against a given list of ACPI IDs */
		id = acpi_match_device(dev->driver->acpi_match_table, dev);
		if (!id)
		return -ENODEV;

		/* Get LPCPD GPIO from ACPI */
		gpiod_lpcpd = devm_gpiod_get_index(dev, "TPM IO LPCPD", 1,
		GPIOD_OUT_HIGH);
		if (IS_ERR(gpiod_lpcpd)) {
		dev_err(dev, "Failed to retrieve lpcpd-gpios from acpi.\n");
		phy->io_lpcpd = -1;
		/*
		* lpcpd pin is not specified. This is not an issue as
		* power management can be also managed by TPM specific
		* commands. So leave with a success status code.
		*/
		return 0;
		}

		phy->io_lpcpd = desc_to_gpio(gpiod_lpcpd);

		return 0;
		}

		static int st33zp24_spi_of_request_resources(struct spi_device *spi_dev)
		{
		struct st33zp24_spi_phy *phy = spi_get_drvdata(spi_dev);
		struct device_node *pp;
		struct spi_device *dev = phy->spi_device;
		int gpio;
		int ret;

		pp = spi_dev->dev.of_node;
		pp = dev->dev.of_node;
		if (!pp) {
		dev_err(&spi_dev->dev, "No platform data\n");
		dev_err(&dev->dev, "No platform data\n");
		return -ENODEV;
		}

		/* Get GPIO from device tree */
		gpio = of_get_named_gpio(pp, "lpcpd-gpios", 0);
		if (gpio < 0) {
		dev_err(&spi_dev->dev,
		dev_err(&dev->dev,
		"Failed to retrieve lpcpd-gpios from dts.\n");
		phy->io_lpcpd = -1;
		/*
		@@ -292,20 +254,26 @@ static int st33zp24_spi_of_request_resources(struct spi_device *spi_dev)
		return 0;
		}
		/* GPIO request and configuration */
		ret = devm_gpio_request_one(&spi_dev->dev, gpio,
		ret = devm_gpio_request_one(&dev->dev, gpio,
		GPIOF_OUT_INIT_HIGH, "TPM IO LPCPD");
		if (ret) {
		dev_err(&spi_dev->dev, "Failed to request lpcpd pin\n");
		dev_err(&dev->dev, "Failed to request lpcpd pin\n");
		return -ENODEV;
		}
		phy->io_lpcpd = gpio;

		return 0;
		}
		#else
		static int tpm_stm_spi_of_request_resources(struct st33zp24_spi_phy *phy)
		{
		return -ENODEV;
		}
		#endif

		static int st33zp24_spi_request_resources(struct spi_device *dev)
		static int tpm_stm_spi_request_resources(struct spi_device *dev,
		struct st33zp24_spi_phy *phy)
		{
		struct st33zp24_spi_phy *phy = spi_get_drvdata(dev);
		struct st33zp24_platform_data *pdata;
		int ret;

		@@ -333,12 +301,13 @@ static int st33zp24_spi_request_resources(struct spi_device *dev)
		}

		/*
		* st33zp24_spi_probe initialize the TPM device
		* tpm_st33_spi_probe initialize the TPM device
		* @param: dev, the spi_device drescription (TPM SPI description).
		* @return: 0 in case of success.
		* or a negative value describing the error.
		*/
		static int st33zp24_spi_probe(struct spi_device *dev)
		static int
		tpm_st33_spi_probe(struct spi_device *dev)
		{
		int ret;
		struct st33zp24_platform_data *pdata;
		@@ -357,25 +326,21 @@ static int st33zp24_spi_probe(struct spi_device *dev)
		return -ENOMEM;

		phy->spi_device = dev;

		spi_set_drvdata(dev, phy);

		pdata = dev->dev.platform_data;
		if (!pdata && dev->dev.of_node) {
		ret = st33zp24_spi_of_request_resources(dev);
		ret = tpm_stm_spi_of_request_resources(phy);
		if (ret)
		return ret;
		} else if (pdata) {
		ret = st33zp24_spi_request_resources(dev);
		if (ret)
		return ret;
		} else if (ACPI_HANDLE(&dev->dev)) {
		ret = st33zp24_spi_acpi_request_resources(dev);
		ret = tpm_stm_spi_request_resources(dev, phy);
		if (ret)
		return ret;
		}

		phy->latency = st33zp24_spi_evaluate_latency(phy);
		phy->spi_xfer.tx_buf = phy->tx_buf;
		phy->spi_xfer.rx_buf = phy->rx_buf;

		phy->latency = evaluate_latency(phy);
		if (phy->latency <= 0)
		return -ENODEV;

		@@ -384,11 +349,11 @@ static int st33zp24_spi_probe(struct spi_device *dev)
		}

		/*
		* st33zp24_spi_remove remove the TPM device
		* tpm_st33_spi_remove remove the TPM device
		* @param: client, the spi_device drescription (TPM SPI description).
		* @return: 0 in case of success.
		*/
		static int st33zp24_spi_remove(struct spi_device *dev)
		static int tpm_st33_spi_remove(struct spi_device *dev)
		{
		struct tpm_chip *chip = spi_get_drvdata(dev);

		@@ -401,34 +366,29 @@ static const struct spi_device_id st33zp24_spi_id[] = {
		};
		MODULE_DEVICE_TABLE(spi, st33zp24_spi_id);

		#ifdef CONFIG_OF
		static const struct of_device_id of_st33zp24_spi_match[] = {
		{ .compatible = "st,st33zp24-spi", },
		{}
		};
		MODULE_DEVICE_TABLE(of, of_st33zp24_spi_match);

		static const struct acpi_device_id st33zp24_spi_acpi_match[] = {
		{"SMO3324"},
		{}
		};
		MODULE_DEVICE_TABLE(acpi, st33zp24_spi_acpi_match);
		#endif

		static SIMPLE_DEV_PM_OPS(st33zp24_spi_ops, st33zp24_pm_suspend,
		st33zp24_pm_resume);

		static struct spi_driver st33zp24_spi_driver = {
		static struct spi_driver tpm_st33_spi_driver = {
		.driver = {
		.name = TPM_ST33_SPI,
		.pm = &st33zp24_spi_ops,
		.of_match_table = of_match_ptr(of_st33zp24_spi_match),
		.acpi_match_table = ACPI_PTR(st33zp24_spi_acpi_match),
		},
		.probe = st33zp24_spi_probe,
		.remove = st33zp24_spi_remove,
		.probe = tpm_st33_spi_probe,
		.remove = tpm_st33_spi_remove,
		.id_table = st33zp24_spi_id,
		};

		module_spi_driver(st33zp24_spi_driver);
		module_spi_driver(tpm_st33_spi_driver);

		MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)");
		MODULE_DESCRIPTION("STM TPM 1.2 SPI ST33 Driver");