diff options
Diffstat (limited to 'drivers/gpu/drm/mgag200/mgag200_i2c.c')
| -rw-r--r-- | drivers/gpu/drm/mgag200/mgag200_i2c.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/drivers/gpu/drm/mgag200/mgag200_i2c.c b/drivers/gpu/drm/mgag200/mgag200_i2c.c new file mode 100644 index 000000000..0c48bdf3e --- /dev/null +++ b/drivers/gpu/drm/mgag200/mgag200_i2c.c @@ -0,0 +1,130 @@ +/* + * 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 "mgag200_drv.h" + +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 mga_gpio_setsda(void *data, int state) +{ + struct mga_i2c_chan *i2c = data; + struct mga_device *mdev = to_mga_device(i2c->dev); + mga_i2c_set(mdev, i2c->data, state); +} + +static void mga_gpio_setscl(void *data, int state) +{ + struct mga_i2c_chan *i2c = data; + struct mga_device *mdev = to_mga_device(i2c->dev); + mga_i2c_set(mdev, i2c->clock, state); +} + +static int mga_gpio_getsda(void *data) +{ + struct mga_i2c_chan *i2c = data; + struct mga_device *mdev = to_mga_device(i2c->dev); + return (mga_i2c_read_gpio(mdev) & i2c->data) ? 1 : 0; +} + +static int mga_gpio_getscl(void *data) +{ + struct mga_i2c_chan *i2c = data; + struct mga_device *mdev = to_mga_device(i2c->dev); + return (mga_i2c_read_gpio(mdev) & i2c->clock) ? 1 : 0; +} + +static void mgag200_i2c_release(void *res) +{ + struct mga_i2c_chan *i2c = res; + + i2c_del_adapter(&i2c->adapter); +} + +int mgag200_i2c_init(struct mga_device *mdev, struct mga_i2c_chan *i2c) +{ + struct drm_device *dev = &mdev->base; + const struct mgag200_device_info *info = mdev->info; + int ret; + + WREG_DAC(MGA1064_GEN_IO_CTL2, 1); + WREG_DAC(MGA1064_GEN_IO_DATA, 0xff); + WREG_DAC(MGA1064_GEN_IO_CTL, 0); + + i2c->data = BIT(info->i2c.data_bit); + i2c->clock = BIT(info->i2c.clock_bit); + i2c->adapter.owner = THIS_MODULE; + i2c->adapter.class = I2C_CLASS_DDC; + i2c->adapter.dev.parent = dev->dev; + i2c->dev = dev; + i2c_set_adapdata(&i2c->adapter, i2c); + snprintf(i2c->adapter.name, sizeof(i2c->adapter.name), "mga i2c"); + + i2c->adapter.algo_data = &i2c->bit; + + i2c->bit.udelay = 10; + i2c->bit.timeout = 2; + i2c->bit.data = i2c; + i2c->bit.setsda = mga_gpio_setsda; + i2c->bit.setscl = mga_gpio_setscl; + i2c->bit.getsda = mga_gpio_getsda; + i2c->bit.getscl = mga_gpio_getscl; + + ret = i2c_bit_add_bus(&i2c->adapter); + if (ret) + return ret; + + return devm_add_action_or_reset(dev->dev, mgag200_i2c_release, i2c); +} |