diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-platdrv.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-platdrv.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c new file mode 100644 index 00000000000..402ec3970fe --- /dev/null +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -0,0 +1,306 @@ +/* + * Synopsys DesignWare I2C adapter driver (master only). + * + * Based on the TI DAVINCI I2C adapter driver. + * + * Copyright (C) 2006 Texas Instruments. + * Copyright (C) 2007 MontaVista Software Inc. + * Copyright (C) 2009 Provigent Ltd. + * + * ---------------------------------------------------------------------------- + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * ---------------------------------------------------------------------------- + * + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/clk.h> +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/err.h> +#include <linux/interrupt.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/pm_runtime.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include "i2c-designware-core.h" + +static struct i2c_algorithm i2c_dw_algo = { + .master_xfer = i2c_dw_xfer, + .functionality = i2c_dw_func, +}; +static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev) +{ + return clk_get_rate(dev->clk)/1000; +} + +#ifdef CONFIG_ACPI +static void dw_i2c_acpi_params(struct platform_device *pdev, char method[], + u16 *hcnt, u16 *lcnt, u32 *sda_hold) +{ + struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER }; + acpi_handle handle = ACPI_HANDLE(&pdev->dev); + union acpi_object *obj; + + if (ACPI_FAILURE(acpi_evaluate_object(handle, method, NULL, &buf))) + return; + + obj = (union acpi_object *)buf.pointer; + if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 3) { + const union acpi_object *objs = obj->package.elements; + + *hcnt = (u16)objs[0].integer.value; + *lcnt = (u16)objs[1].integer.value; + if (sda_hold) + *sda_hold = (u32)objs[2].integer.value; + } + + kfree(buf.pointer); +} + +static int dw_i2c_acpi_configure(struct platform_device *pdev) +{ + struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + bool fs_mode = dev->master_cfg & DW_IC_CON_SPEED_FAST; + + if (!ACPI_HANDLE(&pdev->dev)) + return -ENODEV; + + dev->adapter.nr = -1; + dev->tx_fifo_depth = 32; + dev->rx_fifo_depth = 32; + + /* + * Try to get SDA hold time and *CNT values from an ACPI method if + * it exists for both supported speed modes. + */ + dw_i2c_acpi_params(pdev, "SSCN", &dev->ss_hcnt, &dev->ss_lcnt, + fs_mode ? NULL : &dev->sda_hold_time); + dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, + fs_mode ? &dev->sda_hold_time : NULL); + + return 0; +} + +static const struct acpi_device_id dw_i2c_acpi_match[] = { + { "INT33C2", 0 }, + { "INT33C3", 0 }, + { "INT3432", 0 }, + { "INT3433", 0 }, + { "80860F41", 0 }, + { } +}; +MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); +#else +static inline int dw_i2c_acpi_configure(struct platform_device *pdev) +{ + return -ENODEV; +} +#endif + +static int dw_i2c_probe(struct platform_device *pdev) +{ + struct dw_i2c_dev *dev; + struct i2c_adapter *adap; + struct resource *mem; + int irq, r; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "no irq resource?\n"); + return irq; /* -ENXIO */ + } + + dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL); + if (!dev) + return -ENOMEM; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dev->base = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(dev->base)) + return PTR_ERR(dev->base); + + init_completion(&dev->cmd_complete); + mutex_init(&dev->lock); + dev->dev = &pdev->dev; + dev->irq = irq; + platform_set_drvdata(pdev, dev); + + dev->clk = devm_clk_get(&pdev->dev, NULL); + dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz; + + if (IS_ERR(dev->clk)) + return PTR_ERR(dev->clk); + clk_prepare_enable(dev->clk); + + if (pdev->dev.of_node) { + u32 ht = 0; + u32 ic_clk = dev->get_clk_rate_khz(dev); + + of_property_read_u32(pdev->dev.of_node, + "i2c-sda-hold-time-ns", &ht); + dev->sda_hold_time = div_u64((u64)ic_clk * ht + 500000, + 1000000); + + of_property_read_u32(pdev->dev.of_node, + "i2c-sda-falling-time-ns", + &dev->sda_falling_time); + of_property_read_u32(pdev->dev.of_node, + "i2c-scl-falling-time-ns", + &dev->scl_falling_time); + } + + dev->functionality = + I2C_FUNC_I2C | + I2C_FUNC_10BIT_ADDR | + I2C_FUNC_SMBUS_BYTE | + I2C_FUNC_SMBUS_BYTE_DATA | + I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_I2C_BLOCK; + dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST; + + /* Try first if we can configure the device from ACPI */ + r = dw_i2c_acpi_configure(pdev); + if (r) { + u32 param1 = i2c_dw_read_comp_param(dev); + + dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; + dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 1; + dev->adapter.nr = pdev->id; + } + r = i2c_dw_init(dev); + if (r) + return r; + + i2c_dw_disable_int(dev); + r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED, + pdev->name, dev); + if (r) { + dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq); + return r; + } + + adap = &dev->adapter; + i2c_set_adapdata(adap, dev); + adap->owner = THIS_MODULE; + adap->class = I2C_CLASS_HWMON | I2C_CLASS_DEPRECATED; + strlcpy(adap->name, "Synopsys DesignWare I2C adapter", + sizeof(adap->name)); + adap->algo = &i2c_dw_algo; + adap->dev.parent = &pdev->dev; + adap->dev.of_node = pdev->dev.of_node; + + r = i2c_add_numbered_adapter(adap); + if (r) { + dev_err(&pdev->dev, "failure adding adapter\n"); + return r; + } + + pm_runtime_set_autosuspend_delay(&pdev->dev, 1000); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + return 0; +} + +static int dw_i2c_remove(struct platform_device *pdev) +{ + struct dw_i2c_dev *dev = platform_get_drvdata(pdev); + + pm_runtime_get_sync(&pdev->dev); + + i2c_del_adapter(&dev->adapter); + + i2c_dw_disable(dev); + + pm_runtime_put(&pdev->dev); + pm_runtime_disable(&pdev->dev); + + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id dw_i2c_of_match[] = { + { .compatible = "snps,designware-i2c", }, + {}, +}; +MODULE_DEVICE_TABLE(of, dw_i2c_of_match); +#endif + +#ifdef CONFIG_PM +static int dw_i2c_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); + + i2c_dw_disable(i_dev); + clk_disable_unprepare(i_dev->clk); + + return 0; +} + +static int dw_i2c_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev); + + clk_prepare_enable(i_dev->clk); + i2c_dw_init(i_dev); + + return 0; +} +#endif + +static UNIVERSAL_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, + dw_i2c_resume, NULL); + +/* work with hotplug and coldplug */ +MODULE_ALIAS("platform:i2c_designware"); + +static struct platform_driver dw_i2c_driver = { + .probe = dw_i2c_probe, + .remove = dw_i2c_remove, + .driver = { + .name = "i2c_designware", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(dw_i2c_of_match), + .acpi_match_table = ACPI_PTR(dw_i2c_acpi_match), + .pm = &dw_i2c_dev_pm_ops, + }, +}; + +static int __init dw_i2c_init_driver(void) +{ + return platform_driver_register(&dw_i2c_driver); +} +subsys_initcall(dw_i2c_init_driver); + +static void __exit dw_i2c_exit_driver(void) +{ + platform_driver_unregister(&dw_i2c_driver); +} +module_exit(dw_i2c_exit_driver); + +MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>"); +MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); +MODULE_LICENSE("GPL"); |