tpm/tpm_i2c_stm_st33: Split tpm_i2c_tpm_st33 in 2 layers (core + phy)

tpm_i2c_stm_st33 is a TIS 1.2 TPM with a core interface which can be used
by different phy such as i2c or spi. The core part is called st33zp24 which
is also the main part reference.

include/linux/platform_data/tpm_stm_st33.h is renamed consequently.
The driver is also split into an i2c phy in charge of sending/receiving
data as well as managing platform data or dts configuration.

Acked-by: Jarkko Sakkinen <jarkko.sakknen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

1 files changed, 278 insertions, 0 deletions

diff --git a/drivers/char/tpm/st33zp24/i2c.c b/drivers/char/tpm/st33zp24/i2c.c
new file mode 100644
index 000000000000..95e3091c4590
--- /dev/null
+++ b/drivers/char/tpm/st33zp24/i2c.c
@@ -0,0 +1,278 @@
+/*
+ * STMicroelectronics TPM I2C Linux driver for TPM ST33ZP24
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
+#include <linux/tpm.h>
+#include <linux/platform_data/st33zp24.h>
+
+#include "st33zp24.h"
+
+#define TPM_DUMMY_BYTE			0xAA
+#define TPM_WRITE_DIRECTION		0x80
+#define TPM_BUFSIZE			2048
+
+struct st33zp24_i2c_phy {
+	struct i2c_client *client;
+	u8 buf[TPM_BUFSIZE + 1];
+	int io_lpcpd;
+};
+
+/*
+ * write8_reg
+ * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: tpm_register, the tpm tis register where the data should be written
+ * @param: tpm_data, the tpm_data to write inside the tpm_register
+ * @param: tpm_size, The length of the data
+ * @return: Returns negative errno, or else the number of bytes written.
+ */
+static int write8_reg(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size)
+{
+	struct st33zp24_i2c_phy *phy = phy_id;
+
+	phy->buf[0] = tpm_register;
+	memcpy(phy->buf + 1, tpm_data, tpm_size);
+	return i2c_master_send(phy->client, phy->buf, tpm_size + 1);
+} /* write8_reg() */
+
+/*
+ * read8_reg
+ * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: tpm_register, the tpm tis register where the data should be read
+ * @param: tpm_data, the TPM response
+ * @param: tpm_size, tpm TPM response size to read.
+ * @return: number of byte read successfully: should be one if success.
+ */
+static int read8_reg(void *phy_id, u8 tpm_register, u8 *tpm_data, int tpm_size)
+{
+	struct st33zp24_i2c_phy *phy = phy_id;
+	u8 status = 0;
+	u8 data;
+
+	data = TPM_DUMMY_BYTE;
+	status = write8_reg(phy, tpm_register, &data, 1);
+	if (status == 2)
+		status = i2c_master_recv(phy->client, tpm_data, tpm_size);
+	return status;
+} /* read8_reg() */
+
+/*
+ * st33zp24_i2c_send
+ * Send byte to the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: phy_id, the phy description
+ * @param: tpm_register, the tpm tis register where the data should be written
+ * @param: tpm_data, the tpm_data to write inside the tpm_register
+ * @param: tpm_size, the length of the data
+ * @return: number of byte written successfully: should be one if success.
+ */
+static int st33zp24_i2c_send(void *phy_id, u8 tpm_register, u8 *tpm_data,
+			     int tpm_size)
+{
+	return write8_reg(phy_id, tpm_register | TPM_WRITE_DIRECTION, tpm_data,
+			  tpm_size);
+}
+
+/*
+ * st33zp24_i2c_recv
+ * Recv byte from the TIS register according to the ST33ZP24 I2C protocol.
+ * @param: phy_id, the phy description
+ * @param: tpm_register, the tpm tis register where the data should be read
+ * @param: tpm_data, the TPM response
+ * @param: tpm_size, tpm TPM response size to read.
+ * @return: number of byte read successfully: should be one if success.
+ */
+static int st33zp24_i2c_recv(void *phy_id, u8 tpm_register, u8 *tpm_data,
+			     int tpm_size)
+{
+	return read8_reg(phy_id, tpm_register, tpm_data, tpm_size);
+}
+
+static const struct st33zp24_phy_ops i2c_phy_ops = {
+	.send = st33zp24_i2c_send,
+	.recv = st33zp24_i2c_recv,
+};
+
+#ifdef CONFIG_OF
+static int st33zp24_i2c_of_request_resources(struct st33zp24_i2c_phy *phy)
+{
+	struct device_node *pp;
+	struct i2c_client *client = phy->client;
+	int gpio;
+	int ret;
+
+	pp = client->dev.of_node;
+	if (!pp) {
+		dev_err(&client->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(&client->dev,
+			"Failed to retrieve lpcpd-gpios from dts.\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;
+	}
+	/* GPIO request and configuration */
+	ret = devm_gpio_request_one(&client->dev, gpio,
+			GPIOF_OUT_INIT_HIGH, "TPM IO LPCPD");
+	if (ret) {
+		dev_err(&client->dev, "Failed to request lpcpd pin\n");
+		return -ENODEV;
+	}
+	phy->io_lpcpd = gpio;
+
+	return 0;
+}
+#else
+static int st33zp24_i2c_of_request_resources(struct st33zp24_i2c_phy *phy)
+{
+	return -ENODEV;
+}
+#endif
+
+static int st33zp24_i2c_request_resources(struct i2c_client *client,
+					  struct st33zp24_i2c_phy *phy)
+{
+	struct st33zp24_platform_data *pdata;
+	int ret;
+
+	pdata = client->dev.platform_data;
+	if (!pdata) {
+		dev_err(&client->dev, "No platform data\n");
+		return -ENODEV;
+	}
+
+	/* store for late use */
+	phy->io_lpcpd = pdata->io_lpcpd;
+
+	if (gpio_is_valid(pdata->io_lpcpd)) {
+		ret = devm_gpio_request_one(&client->dev,
+				pdata->io_lpcpd, GPIOF_OUT_INIT_HIGH,
+				"TPM IO_LPCPD");
+		if (ret) {
+			dev_err(&client->dev, "Failed to request lpcpd pin\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * st33zp24_i2c_probe initialize the TPM device
+ * @param: client, the i2c_client drescription (TPM I2C description).
+ * @param: id, the i2c_device_id struct.
+ * @return: 0 in case of success.
+ *	 -1 in other case.
+ */
+static int st33zp24_i2c_probe(struct i2c_client *client,
+			      const struct i2c_device_id *id)
+{
+	int ret;
+	struct st33zp24_platform_data *pdata;
+	struct st33zp24_i2c_phy *phy;
+
+	if (!client) {
+		pr_info("%s: i2c client is NULL. Device not accessible.\n",
+			__func__);
+		return -ENODEV;
+	}
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_info(&client->dev, "client not i2c capable\n");
+		return -ENODEV;
+	}
+
+	phy = devm_kzalloc(&client->dev, sizeof(struct st33zp24_i2c_phy),
+			   GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->client = client;
+	pdata = client->dev.platform_data;
+	if (!pdata && client->dev.of_node) {
+		ret = st33zp24_i2c_of_request_resources(phy);
+		if (ret)
+			return ret;
+	} else if (pdata) {
+		ret = st33zp24_i2c_request_resources(client, phy);
+		if (ret)
+			return ret;
+	}
+
+	return st33zp24_probe(phy, &i2c_phy_ops, &client->dev, client->irq,
+			      phy->io_lpcpd);
+}
+
+/*
+ * st33zp24_i2c_remove remove the TPM device
+ * @param: client, the i2c_client description (TPM I2C description).
+ * @return: 0 in case of success.
+ */
+static int st33zp24_i2c_remove(struct i2c_client *client)
+{
+	struct tpm_chip *chip = i2c_get_clientdata(client);
+
+	return st33zp24_remove(chip);
+}
+
+static const struct i2c_device_id st33zp24_i2c_id[] = {
+	{TPM_ST33_I2C, 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, st33zp24_i2c_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id of_st33zp24_i2c_match[] = {
+	{ .compatible = "st,st33zp24-i2c", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, of_st33zp24_i2c_match);
+#endif
+
+static SIMPLE_DEV_PM_OPS(st33zp24_i2c_ops, st33zp24_pm_suspend,
+			 st33zp24_pm_resume);
+
+static struct i2c_driver st33zp24_i2c_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = TPM_ST33_I2C,
+		.pm = &st33zp24_i2c_ops,
+		.of_match_table = of_match_ptr(of_st33zp24_i2c_match),
+	},
+	.probe = st33zp24_i2c_probe,
+	.remove = st33zp24_i2c_remove,
+	.id_table = st33zp24_i2c_id
+};
+
+module_i2c_driver(st33zp24_i2c_driver);
+
+MODULE_AUTHOR("TPM support (TPMsupport@list.st.com)");
+MODULE_DESCRIPTION("STM TPM 1.2 I2C ST33 Driver");
+MODULE_VERSION("1.3.0");
+MODULE_LICENSE("GPL");