drivers/i2c/busses/i2c-thunderx-pcidrv.c - linux - Git at Google

 /*
  * Cavium ThunderX i2c driver.
  *
  * Copyright (C) 2015,2016 Cavium Inc.
  * Authors: Fred Martin <fmartin@caviumnetworks.com>
  *	    Jan Glauber <jglauber@cavium.com>
  *
  * This file is licensed under the terms of the GNU General Public
  * License version 2. This program is licensed "as is" without any
  * warranty of any kind, whether express or implied.
  */

 #include <linux/acpi.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/i2c-smbus.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_irq.h>
 #include <linux/pci.h>

 #include "i2c-octeon-core.h"

 #define DRV_NAME "i2c-thunderx"

 #define PCI_DEVICE_ID_THUNDER_TWSI	0xa012

 #define SYS_FREQ_DEFAULT		700000000

 #define TWSI_INT_ENA_W1C		0x1028
 #define TWSI_INT_ENA_W1S		0x1030

 /*
  * Enable the CORE interrupt.
  * The interrupt will be asserted when there is non-STAT_IDLE state in the
  * SW_TWSI_EOP_TWSI_STAT register.
  */
 static void thunder_i2c_int_enable(struct octeon_i2c *i2c)
 {
 	octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
 				i2c->twsi_base + TWSI_INT_ENA_W1S);
 }

 /*
  * Disable the CORE interrupt.
  */
 static void thunder_i2c_int_disable(struct octeon_i2c *i2c)
 {
 	octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
 				i2c->twsi_base + TWSI_INT_ENA_W1C);
 }

 static void thunder_i2c_hlc_int_enable(struct octeon_i2c *i2c)
 {
 	octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
 				i2c->twsi_base + TWSI_INT_ENA_W1S);
 }

 static void thunder_i2c_hlc_int_disable(struct octeon_i2c *i2c)
 {
 	octeon_i2c_writeq_flush(TWSI_INT_ST_INT | TWSI_INT_TS_INT,
 				i2c->twsi_base + TWSI_INT_ENA_W1C);
 }

 static u32 thunderx_i2c_functionality(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
 	       I2C_FUNC_SMBUS_READ_BLOCK_DATA | I2C_SMBUS_BLOCK_PROC_CALL;
 }

 static const struct i2c_algorithm thunderx_i2c_algo = {
 	.master_xfer = octeon_i2c_xfer,
 	.functionality = thunderx_i2c_functionality,
 };

 static const struct i2c_adapter thunderx_i2c_ops = {
 	.owner	= THIS_MODULE,
 	.name	= "ThunderX adapter",
 	.algo	= &thunderx_i2c_algo,
 };

 static void thunder_i2c_clock_enable(struct device *dev, struct octeon_i2c *i2c)
 {
 	int ret;

 	if (acpi_disabled) {
 		/* DT */
 		i2c->clk = clk_get(dev, NULL);
 		if (IS_ERR(i2c->clk)) {
 			i2c->clk = NULL;
 			goto skip;
 		}

 		ret = clk_prepare_enable(i2c->clk);
 		if (ret)
 			goto skip;
 		i2c->sys_freq = clk_get_rate(i2c->clk);
 	} else {
 		/* ACPI */
 		device_property_read_u32(dev, "sclk", &i2c->sys_freq);
 	}

 skip:
 	if (!i2c->sys_freq)
 		i2c->sys_freq = SYS_FREQ_DEFAULT;
 }

 static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk)
 {
 	if (!clk)
 		return;
 	clk_disable_unprepare(clk);
 	clk_put(clk);
 }

 static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c,
 				      struct device_node *node)
 {
 	if (!node)
 		return -EINVAL;

 	i2c->alert_data.irq = irq_of_parse_and_map(node, 0);
 	if (!i2c->alert_data.irq)
 		return -EINVAL;

 	i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data);
 	if (!i2c->ara)
 		return -ENODEV;
 	return 0;
 }

 static int thunder_i2c_smbus_setup(struct octeon_i2c *i2c,
 				   struct device_node *node)
 {
 	/* TODO: ACPI support */
 	if (!acpi_disabled)
 		return -EOPNOTSUPP;

 	return thunder_i2c_smbus_setup_of(i2c, node);
 }

 static void thunder_i2c_smbus_remove(struct octeon_i2c *i2c)
 {
 	i2c_unregister_device(i2c->ara);
 }

 static int thunder_i2c_probe_pci(struct pci_dev *pdev,
 				 const struct pci_device_id *ent)
 {
 	struct device *dev = &pdev->dev;
 	struct octeon_i2c *i2c;
 	int ret;

 	i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
 	if (!i2c)
 		return -ENOMEM;

 	i2c->roff.sw_twsi = 0x1000;
 	i2c->roff.twsi_int = 0x1010;
 	i2c->roff.sw_twsi_ext = 0x1018;

 	i2c->dev = dev;
 	pci_set_drvdata(pdev, i2c);
 	ret = pcim_enable_device(pdev);
 	if (ret)
 		return ret;

 	ret = pci_request_regions(pdev, DRV_NAME);
 	if (ret)
 		return ret;

 	i2c->twsi_base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
 	if (!i2c->twsi_base)
 		return -EINVAL;

 	thunder_i2c_clock_enable(dev, i2c);
 	ret = device_property_read_u32(dev, "clock-frequency", &i2c->twsi_freq);
 	if (ret)
 		i2c->twsi_freq = 100000;

 	init_waitqueue_head(&i2c->queue);

 	i2c->int_enable = thunder_i2c_int_enable;
 	i2c->int_disable = thunder_i2c_int_disable;
 	i2c->hlc_int_enable = thunder_i2c_hlc_int_enable;
 	i2c->hlc_int_disable = thunder_i2c_hlc_int_disable;

 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
 	if (ret < 0)
 		goto error;

 	ret = devm_request_irq(dev, pci_irq_vector(pdev, 0), octeon_i2c_isr, 0,
 			       DRV_NAME, i2c);
 	if (ret)
 		goto error;

 	ret = octeon_i2c_init_lowlevel(i2c);
 	if (ret)
 		goto error;

 	octeon_i2c_set_clock(i2c);

 	i2c->adap = thunderx_i2c_ops;
 	i2c->adap.retries = 5;
 	i2c->adap.class = I2C_CLASS_HWMON;
 	i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
 	i2c->adap.dev.parent = dev;
 	i2c->adap.dev.of_node = pdev->dev.of_node;
 	snprintf(i2c->adap.name, sizeof(i2c->adap.name),
 		 "Cavium ThunderX i2c adapter at %s", dev_name(dev));
 	i2c_set_adapdata(&i2c->adap, i2c);

 	ret = i2c_add_adapter(&i2c->adap);
 	if (ret)
 		goto error;

 	dev_info(i2c->dev, "Probed. Set system clock to %u\n", i2c->sys_freq);

 	ret = thunder_i2c_smbus_setup(i2c, pdev->dev.of_node);
 	if (ret)
 		dev_info(dev, "SMBUS alert not active on this bus\n");

 	return 0;

 error:
 	thunder_i2c_clock_disable(dev, i2c->clk);
 	return ret;
 }

 static void thunder_i2c_remove_pci(struct pci_dev *pdev)
 {
 	struct octeon_i2c *i2c = pci_get_drvdata(pdev);

 	thunder_i2c_smbus_remove(i2c);
 	thunder_i2c_clock_disable(&pdev->dev, i2c->clk);
 	i2c_del_adapter(&i2c->adap);
 }

 static const struct pci_device_id thunder_i2c_pci_id_table[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_THUNDER_TWSI) },
 	{ 0, }
 };

 MODULE_DEVICE_TABLE(pci, thunder_i2c_pci_id_table);

 static struct pci_driver thunder_i2c_pci_driver = {
 	.name		= DRV_NAME,
 	.id_table	= thunder_i2c_pci_id_table,
 	.probe		= thunder_i2c_probe_pci,
 	.remove		= thunder_i2c_remove_pci,
 };

 module_pci_driver(thunder_i2c_pci_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Fred Martin <fmartin@caviumnetworks.com>");
 MODULE_DESCRIPTION("I2C-Bus adapter for Cavium ThunderX SOC");
	/*
	* Cavium ThunderX i2c driver.
	*
	* Copyright (C) 2015,2016 Cavium Inc.
	* Authors: Fred Martin <fmartin@caviumnetworks.com>
	* Jan Glauber <jglauber@cavium.com>
	*
	* This file is licensed under the terms of the GNU General Public
	* License version 2. This program is licensed "as is" without any
	* warranty of any kind, whether express or implied.
	*/

	#include <linux/acpi.h>
	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/i2c.h>
	#include <linux/i2c-smbus.h>
	#include <linux/interrupt.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of_irq.h>
	#include <linux/pci.h>

	#include "i2c-octeon-core.h"

	#define DRV_NAME "i2c-thunderx"

	#define PCI_DEVICE_ID_THUNDER_TWSI 0xa012

	#define SYS_FREQ_DEFAULT 700000000

	#define TWSI_INT_ENA_W1C 0x1028
	#define TWSI_INT_ENA_W1S 0x1030

	/*
	* Enable the CORE interrupt.
	* The interrupt will be asserted when there is non-STAT_IDLE state in the
	* SW_TWSI_EOP_TWSI_STAT register.
	*/
	static void thunder_i2c_int_enable(struct octeon_i2c *i2c)
	{
	octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
	i2c->twsi_base + TWSI_INT_ENA_W1S);
	}

	/*
	* Disable the CORE interrupt.
	*/
	static void thunder_i2c_int_disable(struct octeon_i2c *i2c)
	{
	octeon_i2c_writeq_flush(TWSI_INT_CORE_INT,
	i2c->twsi_base + TWSI_INT_ENA_W1C);
	}

	static void thunder_i2c_hlc_int_enable(struct octeon_i2c *i2c)
	{
	octeon_i2c_writeq_flush(TWSI_INT_ST_INT \| TWSI_INT_TS_INT,
	i2c->twsi_base + TWSI_INT_ENA_W1S);
	}

	static void thunder_i2c_hlc_int_disable(struct octeon_i2c *i2c)
	{
	octeon_i2c_writeq_flush(TWSI_INT_ST_INT \| TWSI_INT_TS_INT,
	i2c->twsi_base + TWSI_INT_ENA_W1C);
	}

	static u32 thunderx_i2c_functionality(struct i2c_adapter *adap)
	{
	return I2C_FUNC_I2C \| (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) \|
	I2C_FUNC_SMBUS_READ_BLOCK_DATA \| I2C_SMBUS_BLOCK_PROC_CALL;
	}

	static const struct i2c_algorithm thunderx_i2c_algo = {
	.master_xfer = octeon_i2c_xfer,
	.functionality = thunderx_i2c_functionality,
	};

	static const struct i2c_adapter thunderx_i2c_ops = {
	.owner = THIS_MODULE,
	.name = "ThunderX adapter",
	.algo = &thunderx_i2c_algo,
	};

	static void thunder_i2c_clock_enable(struct device dev, struct octeon_i2c i2c)
	{
	int ret;

	if (acpi_disabled) {
	/* DT */
	i2c->clk = clk_get(dev, NULL);
	if (IS_ERR(i2c->clk)) {
	i2c->clk = NULL;
	goto skip;
	}

	ret = clk_prepare_enable(i2c->clk);
	if (ret)
	goto skip;
	i2c->sys_freq = clk_get_rate(i2c->clk);
	} else {
	/* ACPI */
	device_property_read_u32(dev, "sclk", &i2c->sys_freq);
	}

	skip:
	if (!i2c->sys_freq)
	i2c->sys_freq = SYS_FREQ_DEFAULT;
	}

	static void thunder_i2c_clock_disable(struct device dev, struct clk clk)
	{
	if (!clk)
	return;
	clk_disable_unprepare(clk);
	clk_put(clk);
	}

	static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c,
	struct device_node *node)
	{
	if (!node)
	return -EINVAL;

	i2c->alert_data.irq = irq_of_parse_and_map(node, 0);
	if (!i2c->alert_data.irq)
	return -EINVAL;

	i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data);
	if (!i2c->ara)
	return -ENODEV;
	return 0;
	}

	static int thunder_i2c_smbus_setup(struct octeon_i2c *i2c,
	struct device_node *node)
	{
	/* TODO: ACPI support */
	if (!acpi_disabled)
	return -EOPNOTSUPP;

	return thunder_i2c_smbus_setup_of(i2c, node);
	}

	static void thunder_i2c_smbus_remove(struct octeon_i2c *i2c)
	{
	i2c_unregister_device(i2c->ara);
	}

	static int thunder_i2c_probe_pci(struct pci_dev *pdev,
	const struct pci_device_id *ent)
	{
	struct device *dev = &pdev->dev;
	struct octeon_i2c *i2c;
	int ret;

	i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
	if (!i2c)
	return -ENOMEM;

	i2c->roff.sw_twsi = 0x1000;
	i2c->roff.twsi_int = 0x1010;
	i2c->roff.sw_twsi_ext = 0x1018;

	i2c->dev = dev;
	pci_set_drvdata(pdev, i2c);
	ret = pcim_enable_device(pdev);
	if (ret)
	return ret;

	ret = pci_request_regions(pdev, DRV_NAME);
	if (ret)
	return ret;

	i2c->twsi_base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
	if (!i2c->twsi_base)
	return -EINVAL;

	thunder_i2c_clock_enable(dev, i2c);
	ret = device_property_read_u32(dev, "clock-frequency", &i2c->twsi_freq);
	if (ret)
	i2c->twsi_freq = 100000;

	init_waitqueue_head(&i2c->queue);

	i2c->int_enable = thunder_i2c_int_enable;
	i2c->int_disable = thunder_i2c_int_disable;
	i2c->hlc_int_enable = thunder_i2c_hlc_int_enable;
	i2c->hlc_int_disable = thunder_i2c_hlc_int_disable;

	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
	if (ret < 0)
	goto error;

	ret = devm_request_irq(dev, pci_irq_vector(pdev, 0), octeon_i2c_isr, 0,
	DRV_NAME, i2c);
	if (ret)
	goto error;

	ret = octeon_i2c_init_lowlevel(i2c);
	if (ret)
	goto error;

	octeon_i2c_set_clock(i2c);

	i2c->adap = thunderx_i2c_ops;
	i2c->adap.retries = 5;
	i2c->adap.class = I2C_CLASS_HWMON;
	i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info;
	i2c->adap.dev.parent = dev;
	i2c->adap.dev.of_node = pdev->dev.of_node;
	snprintf(i2c->adap.name, sizeof(i2c->adap.name),
	"Cavium ThunderX i2c adapter at %s", dev_name(dev));
	i2c_set_adapdata(&i2c->adap, i2c);

	ret = i2c_add_adapter(&i2c->adap);
	if (ret)
	goto error;

	dev_info(i2c->dev, "Probed. Set system clock to %u\n", i2c->sys_freq);

	ret = thunder_i2c_smbus_setup(i2c, pdev->dev.of_node);
	if (ret)
	dev_info(dev, "SMBUS alert not active on this bus\n");

	return 0;

	error:
	thunder_i2c_clock_disable(dev, i2c->clk);
	return ret;
	}

	static void thunder_i2c_remove_pci(struct pci_dev *pdev)
	{
	struct octeon_i2c *i2c = pci_get_drvdata(pdev);

	thunder_i2c_smbus_remove(i2c);
	thunder_i2c_clock_disable(&pdev->dev, i2c->clk);
	i2c_del_adapter(&i2c->adap);
	}

	static const struct pci_device_id thunder_i2c_pci_id_table[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, PCI_DEVICE_ID_THUNDER_TWSI) },
	{ 0, }
	};

	MODULE_DEVICE_TABLE(pci, thunder_i2c_pci_id_table);

	static struct pci_driver thunder_i2c_pci_driver = {
	.name = DRV_NAME,
	.id_table = thunder_i2c_pci_id_table,
	.probe = thunder_i2c_probe_pci,
	.remove = thunder_i2c_remove_pci,
	};

	module_pci_driver(thunder_i2c_pci_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Fred Martin <fmartin@caviumnetworks.com>");
	MODULE_DESCRIPTION("I2C-Bus adapter for Cavium ThunderX SOC");