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/*
* 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 800000000
#define OTX2_REF_FREQ_DEFAULT 100000000
#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 */
if (device_property_read_u32(dev, "sclk", &i2c->sys_freq))
device_property_read_u32(dev, "ioclk", &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)
{
struct i2c_client *ara;
if (!node)
return -EINVAL;
i2c->alert_data.irq = irq_of_parse_and_map(node, 0);
if (!i2c->alert_data.irq)
return -EINVAL;
ara = i2c_new_smbus_alert_device(&i2c->adap, &i2c->alert_data);
if (IS_ERR(ara))
return PTR_ERR(ara);
i2c->ara = ara;
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->roff.mode = 0x1038;
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 = I2C_MAX_STANDARD_MODE_FREQ;
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;
/*
* For OcteonTX2 chips, set reference frequency to 100MHz
* as refclk_src in TWSI_MODE register defaults to 100MHz.
*/
if (octeon_i2c_is_otx2(pdev) && IS_LS_FREQ(i2c->twsi_freq))
i2c->sys_freq = OTX2_REF_FREQ_DEFAULT;
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;
i2c->adap.dev.fwnode = dev->fwnode;
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");
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