diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/i2c/busses/i2c-octeon-platdrv.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-octeon-platdrv.c b/drivers/i2c/busses/i2c-octeon-platdrv.c new file mode 100644 index 000000000..0c227963c --- /dev/null +++ b/drivers/i2c/busses/i2c-octeon-platdrv.c @@ -0,0 +1,284 @@ +/* + * (C) Copyright 2009-2010 + * Nokia Siemens Networks, michael.lawnick.ext@nsn.com + * + * Portions Copyright (C) 2010 - 2016 Cavium, Inc. + * + * This is a driver for the i2c adapter in Cavium Networks' OCTEON processors. + * + * 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/atomic.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#include <asm/octeon/octeon.h> +#include "i2c-octeon-core.h" + +#define DRV_NAME "i2c-octeon" + +/** + * octeon_i2c_int_enable - enable the CORE interrupt + * @i2c: The struct octeon_i2c + * + * The interrupt will be asserted when there is non-STAT_IDLE state in + * the SW_TWSI_EOP_TWSI_STAT register. + */ +static void octeon_i2c_int_enable(struct octeon_i2c *i2c) +{ + octeon_i2c_write_int(i2c, TWSI_INT_CORE_EN); +} + +/* disable the CORE interrupt */ +static void octeon_i2c_int_disable(struct octeon_i2c *i2c) +{ + /* clear TS/ST/IFLG events */ + octeon_i2c_write_int(i2c, 0); +} + +/** + * octeon_i2c_int_enable78 - enable the CORE interrupt + * @i2c: The struct octeon_i2c + * + * The interrupt will be asserted when there is non-STAT_IDLE state in the + * SW_TWSI_EOP_TWSI_STAT register. + */ +static void octeon_i2c_int_enable78(struct octeon_i2c *i2c) +{ + atomic_inc_return(&i2c->int_enable_cnt); + enable_irq(i2c->irq); +} + +static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq) +{ + int count; + + /* + * The interrupt can be disabled in two places, but we only + * want to make the disable_irq_nosync() call once, so keep + * track with the atomic variable. + */ + count = atomic_dec_if_positive(cnt); + if (count >= 0) + disable_irq_nosync(irq); +} + +/* disable the CORE interrupt */ +static void octeon_i2c_int_disable78(struct octeon_i2c *i2c) +{ + __octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq); +} + +/** + * octeon_i2c_hlc_int_enable78 - enable the ST interrupt + * @i2c: The struct octeon_i2c + * + * The interrupt will be asserted when there is non-STAT_IDLE state in + * the SW_TWSI_EOP_TWSI_STAT register. + */ +static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c) +{ + atomic_inc_return(&i2c->hlc_int_enable_cnt); + enable_irq(i2c->hlc_irq); +} + +/* disable the ST interrupt */ +static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c) +{ + __octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq); +} + +/* HLC interrupt service routine */ +static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id) +{ + struct octeon_i2c *i2c = dev_id; + + i2c->hlc_int_disable(i2c); + wake_up(&i2c->queue); + + return IRQ_HANDLED; +} + +static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c) +{ + octeon_i2c_write_int(i2c, TWSI_INT_ST_EN); +} + +static u32 octeon_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 octeon_i2c_algo = { + .master_xfer = octeon_i2c_xfer, + .functionality = octeon_i2c_functionality, +}; + +static const struct i2c_adapter octeon_i2c_ops = { + .owner = THIS_MODULE, + .name = "OCTEON adapter", + .algo = &octeon_i2c_algo, +}; + +static int octeon_i2c_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + int irq, result = 0, hlc_irq = 0; + struct octeon_i2c *i2c; + bool cn78xx_style; + + cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi"); + if (cn78xx_style) { + hlc_irq = platform_get_irq(pdev, 0); + if (hlc_irq < 0) + return hlc_irq; + + irq = platform_get_irq(pdev, 2); + if (irq < 0) + return irq; + } else { + /* All adaptors have an irq. */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + } + + i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); + if (!i2c) { + result = -ENOMEM; + goto out; + } + i2c->dev = &pdev->dev; + + i2c->roff.sw_twsi = 0x00; + i2c->roff.twsi_int = 0x10; + i2c->roff.sw_twsi_ext = 0x18; + + i2c->twsi_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(i2c->twsi_base)) { + result = PTR_ERR(i2c->twsi_base); + goto out; + } + + /* + * "clock-rate" is a legacy binding, the official binding is + * "clock-frequency". Try the official one first and then + * fall back if it doesn't exist. + */ + if (of_property_read_u32(node, "clock-frequency", &i2c->twsi_freq) && + of_property_read_u32(node, "clock-rate", &i2c->twsi_freq)) { + dev_err(i2c->dev, + "no I2C 'clock-rate' or 'clock-frequency' property\n"); + result = -ENXIO; + goto out; + } + + i2c->sys_freq = octeon_get_io_clock_rate(); + + init_waitqueue_head(&i2c->queue); + + i2c->irq = irq; + + if (cn78xx_style) { + i2c->hlc_irq = hlc_irq; + + i2c->int_enable = octeon_i2c_int_enable78; + i2c->int_disable = octeon_i2c_int_disable78; + i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78; + i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78; + + irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN); + irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN); + + result = devm_request_irq(&pdev->dev, i2c->hlc_irq, + octeon_i2c_hlc_isr78, 0, + DRV_NAME, i2c); + if (result < 0) { + dev_err(i2c->dev, "failed to attach interrupt\n"); + goto out; + } + } else { + i2c->int_enable = octeon_i2c_int_enable; + i2c->int_disable = octeon_i2c_int_disable; + i2c->hlc_int_enable = octeon_i2c_hlc_int_enable; + i2c->hlc_int_disable = octeon_i2c_int_disable; + } + + result = devm_request_irq(&pdev->dev, i2c->irq, + octeon_i2c_isr, 0, DRV_NAME, i2c); + if (result < 0) { + dev_err(i2c->dev, "failed to attach interrupt\n"); + goto out; + } + + if (OCTEON_IS_MODEL(OCTEON_CN38XX)) + i2c->broken_irq_check = true; + + result = octeon_i2c_init_lowlevel(i2c); + if (result) { + dev_err(i2c->dev, "init low level failed\n"); + goto out; + } + + octeon_i2c_set_clock(i2c); + + i2c->adap = octeon_i2c_ops; + i2c->adap.timeout = msecs_to_jiffies(2); + i2c->adap.retries = 5; + i2c->adap.bus_recovery_info = &octeon_i2c_recovery_info; + i2c->adap.dev.parent = &pdev->dev; + i2c->adap.dev.of_node = node; + i2c_set_adapdata(&i2c->adap, i2c); + platform_set_drvdata(pdev, i2c); + + result = i2c_add_adapter(&i2c->adap); + if (result < 0) + goto out; + dev_info(i2c->dev, "probed\n"); + return 0; + +out: + return result; +}; + +static int octeon_i2c_remove(struct platform_device *pdev) +{ + struct octeon_i2c *i2c = platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c->adap); + return 0; +}; + +static const struct of_device_id octeon_i2c_match[] = { + { .compatible = "cavium,octeon-3860-twsi", }, + { .compatible = "cavium,octeon-7890-twsi", }, + {}, +}; +MODULE_DEVICE_TABLE(of, octeon_i2c_match); + +static struct platform_driver octeon_i2c_driver = { + .probe = octeon_i2c_probe, + .remove = octeon_i2c_remove, + .driver = { + .name = DRV_NAME, + .of_match_table = octeon_i2c_match, + }, +}; + +module_platform_driver(octeon_i2c_driver); + +MODULE_AUTHOR("Michael Lawnick <michael.lawnick.ext@nsn.com>"); +MODULE_DESCRIPTION("I2C-Bus adapter for Cavium OCTEON processors"); +MODULE_LICENSE("GPL"); |