|  | /* | 
|  | * (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 resource *res_mem; | 
|  | 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; | 
|  |  | 
|  | res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); | 
|  | i2c->twsi_base = devm_ioremap_resource(&pdev->dev, res_mem); | 
|  | 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"); |