diff options
Diffstat (limited to 'drivers/gpu/drm/mgag200/mgag200_ddc.c')
| -rw-r--r-- | drivers/gpu/drm/mgag200/mgag200_ddc.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/gpu/drm/mgag200/mgag200_ddc.c b/drivers/gpu/drm/mgag200/mgag200_ddc.c new file mode 100644 index 000000000000..6d81ea8931e8 --- /dev/null +++ b/drivers/gpu/drm/mgag200/mgag200_ddc.c @@ -0,0 +1,179 @@ +/* + * Copyright 2012 Red Hat Inc. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sub license, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE + * USE OR OTHER DEALINGS IN THE SOFTWARE. + * + * The above copyright notice and this permission notice (including the + * next paragraph) shall be included in all copies or substantial portions + * of the Software. + * + */ +/* + * Authors: Dave Airlie <airlied@redhat.com> + */ + +#include <linux/export.h> +#include <linux/i2c-algo-bit.h> +#include <linux/i2c.h> +#include <linux/pci.h> + +#include <drm/drm_managed.h> + +#include "mgag200_ddc.h" +#include "mgag200_drv.h" + +struct mgag200_ddc { + struct mga_device *mdev; + + int data; + int clock; + + struct i2c_algo_bit_data bit; + struct i2c_adapter adapter; +}; + +static int mga_i2c_read_gpio(struct mga_device *mdev) +{ + WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA); + return RREG8(DAC_DATA); +} + +static void mga_i2c_set_gpio(struct mga_device *mdev, int mask, int val) +{ + int tmp; + + WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL); + tmp = (RREG8(DAC_DATA) & mask) | val; + WREG_DAC(MGA1064_GEN_IO_CTL, tmp); + WREG_DAC(MGA1064_GEN_IO_DATA, 0); +} + +static inline void mga_i2c_set(struct mga_device *mdev, int mask, int state) +{ + if (state) + state = 0; + else + state = mask; + mga_i2c_set_gpio(mdev, ~mask, state); +} + +static void mgag200_ddc_algo_bit_data_setsda(void *data, int state) +{ + struct mgag200_ddc *ddc = data; + + mga_i2c_set(ddc->mdev, ddc->data, state); +} + +static void mgag200_ddc_algo_bit_data_setscl(void *data, int state) +{ + struct mgag200_ddc *ddc = data; + + mga_i2c_set(ddc->mdev, ddc->clock, state); +} + +static int mgag200_ddc_algo_bit_data_getsda(void *data) +{ + struct mgag200_ddc *ddc = data; + + return (mga_i2c_read_gpio(ddc->mdev) & ddc->data) ? 1 : 0; +} + +static int mgag200_ddc_algo_bit_data_getscl(void *data) +{ + struct mgag200_ddc *ddc = data; + + return (mga_i2c_read_gpio(ddc->mdev) & ddc->clock) ? 1 : 0; +} + +static int mgag200_ddc_algo_bit_data_pre_xfer(struct i2c_adapter *adapter) +{ + struct mgag200_ddc *ddc = i2c_get_adapdata(adapter); + struct mga_device *mdev = ddc->mdev; + + /* + * Protect access to I/O registers from concurrent modesetting + * by acquiring the I/O-register lock. + */ + mutex_lock(&mdev->rmmio_lock); + + return 0; +} + +static void mgag200_ddc_algo_bit_data_post_xfer(struct i2c_adapter *adapter) +{ + struct mgag200_ddc *ddc = i2c_get_adapdata(adapter); + struct mga_device *mdev = ddc->mdev; + + mutex_unlock(&mdev->rmmio_lock); +} + +static void mgag200_ddc_release(struct drm_device *dev, void *res) +{ + struct mgag200_ddc *ddc = res; + + i2c_del_adapter(&ddc->adapter); +} + +struct i2c_adapter *mgag200_ddc_create(struct mga_device *mdev) +{ + struct drm_device *dev = &mdev->base; + const struct mgag200_device_info *info = mdev->info; + struct mgag200_ddc *ddc; + struct i2c_algo_bit_data *bit; + struct i2c_adapter *adapter; + int ret; + + ddc = drmm_kzalloc(dev, sizeof(*ddc), GFP_KERNEL); + if (!ddc) + return ERR_PTR(-ENOMEM); + + WREG_DAC(MGA1064_GEN_IO_CTL2, 1); + WREG_DAC(MGA1064_GEN_IO_DATA, 0xff); + WREG_DAC(MGA1064_GEN_IO_CTL, 0); + + ddc->mdev = mdev; + ddc->data = BIT(info->i2c.data_bit); + ddc->clock = BIT(info->i2c.clock_bit); + + bit = &ddc->bit; + bit->data = ddc; + bit->setsda = mgag200_ddc_algo_bit_data_setsda; + bit->setscl = mgag200_ddc_algo_bit_data_setscl; + bit->getsda = mgag200_ddc_algo_bit_data_getsda; + bit->getscl = mgag200_ddc_algo_bit_data_getscl; + bit->pre_xfer = mgag200_ddc_algo_bit_data_pre_xfer; + bit->post_xfer = mgag200_ddc_algo_bit_data_post_xfer; + bit->udelay = 10; + bit->timeout = usecs_to_jiffies(2200); + + adapter = &ddc->adapter; + adapter->owner = THIS_MODULE; + adapter->algo_data = bit; + adapter->dev.parent = dev->dev; + snprintf(adapter->name, sizeof(adapter->name), "Matrox DDC bus"); + i2c_set_adapdata(adapter, ddc); + + ret = i2c_bit_add_bus(adapter); + if (ret) + return ERR_PTR(ret); + + ret = drmm_add_action_or_reset(dev, mgag200_ddc_release, ddc); + if (ret) + return ERR_PTR(ret); + + return adapter; +} |