leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

i2c: thunderx: Add i2c driver for ThunderX SOC

Browse Source 
The ThunderX SOC uses the same i2c block as the Octeon SOC.
The main difference is that on ThunderX the device is a PCI device
so device probing is done via PCI, interrupts are MSI-X. The
clock rates can be set via device tree or ACPI.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Jan Glauber 2016-08-24 23:25:44 +02:00 committed by Wolfram Sang
parent ad83665b46
commit 22d40209de
4 changed files with 234 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/i2c/busses/Kconfig
View File

@ -956,6 +956,16 @@ config I2C_OCTEON
This driver can also be built as a module. If so, the module
will be called i2c-octeon.
config I2C_THUNDERX
tristate "Cavium ThunderX I2C bus support"
depends on 64BIT && PCI && (ARM64 || COMPILE_TEST)
help
Say yes if you want to support the I2C serial bus on Cavium
ThunderX SOC.
This driver can also be built as a module. If so, the module
will be called i2c-thunderx.
config I2C_XILINX
tristate "Xilinx I2C Controller"
depends on HAS_IOMEM

2
drivers/i2c/busses/Makefile
View File

@ -93,6 +93,8 @@ obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_WMT) += i2c-wmt.o
i2c-octeon-objs := i2c-octeon-core.o i2c-octeon-platdrv.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
i2c-thunderx-objs := i2c-octeon-core.o i2c-thunderx-pcidrv.o
obj-$(CONFIG_I2C_THUNDERX) += i2c-thunderx.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
obj-$(CONFIG_I2C_XLP9XX) += i2c-xlp9xx.o

16
drivers/i2c/busses/i2c-octeon-core.h
View File

@ -8,9 +8,15 @@
#include <linux/pci.h>
/* Register offsets */
#define SW_TWSI 0x00
#define TWSI_INT 0x10
#define SW_TWSI_EXT 0x18
#if IS_ENABLED(CONFIG_I2C_THUNDERX)
#define SW_TWSI 0x1000
#define TWSI_INT 0x1010
#define SW_TWSI_EXT 0x1018
#else
#define SW_TWSI 0x00
#define TWSI_INT 0x10
#define SW_TWSI_EXT 0x18
#endif
/* Controller command patterns */
#define SW_TWSI_V BIT_ULL(63) /* Valid bit */
@ -94,6 +100,7 @@
struct octeon_i2c {
wait_queue_head_t queue;
struct i2c_adapter adap;
struct clk *clk;
int irq;
int hlc_irq; /* For cn7890 only */
u32 twsi_freq;
@ -109,6 +116,9 @@ struct octeon_i2c {
void (*hlc_int_disable)(struct octeon_i2c *);
atomic_t int_enable_cnt;
atomic_t hlc_int_enable_cnt;
#if IS_ENABLED(CONFIG_I2C_THUNDERX)
struct msix_entry i2c_msix;
#endif
};
static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)

209
drivers/i2c/busses/i2c-thunderx-pcidrv.c Normal file
View File

@ -0,0 +1,209 @@
/*
* 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/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.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 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;
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);
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_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->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_enable_msix(pdev, &i2c->i2c_msix, 1);
if (ret)
goto error;
ret = devm_request_irq(dev, i2c->i2c_msix.vector, 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.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);
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_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");