diff options
Diffstat (limited to 'drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c')
| -rw-r--r-- | drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c b/drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c new file mode 100644 index 000000000..06b5b2d70 --- /dev/null +++ b/drivers/gpu/drm/gma500/oaktrail_lvds_i2c.c @@ -0,0 +1,169 @@ +/* + * Copyright (c) 2002-2010, Intel Corporation. + * Copyright (c) 2014 ATRON electronic GmbH + * Author: Jan Safrata <jan.nikitenko@gmail.com> + * + * 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, sublicense, 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 above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * 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 NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS 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. + * + */ + +#include <linux/delay.h> +#include <linux/i2c-algo-bit.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/types.h> + +#include "psb_drv.h" +#include "psb_intel_reg.h" + + +/* + * LPC GPIO based I2C bus for LVDS of Atom E6xx + */ + +/*----------------------------------------------------------------------------- + * LPC Register Offsets. Used for LVDS GPIO Bit Bashing. Registers are part + * Atom E6xx [D31:F0] + ----------------------------------------------------------------------------*/ +#define RGEN 0x20 +#define RGIO 0x24 +#define RGLVL 0x28 +#define RGTPE 0x2C +#define RGTNE 0x30 +#define RGGPE 0x34 +#define RGSMI 0x38 +#define RGTS 0x3C + +/* The LVDS GPIO clock lines are GPIOSUS[3] + * The LVDS GPIO data lines are GPIOSUS[4] + */ +#define GPIO_CLOCK 0x08 +#define GPIO_DATA 0x10 + +#define LPC_READ_REG(chan, r) inl((chan)->reg + (r)) +#define LPC_WRITE_REG(chan, r, val) outl((val), (chan)->reg + (r)) + +static int get_clock(void *data) +{ + struct gma_i2c_chan *chan = data; + u32 val; + + val = LPC_READ_REG(chan, RGIO); + val |= GPIO_CLOCK; + LPC_WRITE_REG(chan, RGIO, val); + LPC_READ_REG(chan, RGLVL); + val = (LPC_READ_REG(chan, RGLVL) & GPIO_CLOCK) ? 1 : 0; + + return val; +} + +static int get_data(void *data) +{ + struct gma_i2c_chan *chan = data; + u32 val; + + val = LPC_READ_REG(chan, RGIO); + val |= GPIO_DATA; + LPC_WRITE_REG(chan, RGIO, val); + LPC_READ_REG(chan, RGLVL); + val = (LPC_READ_REG(chan, RGLVL) & GPIO_DATA) ? 1 : 0; + + return val; +} + +static void set_clock(void *data, int state_high) +{ + struct gma_i2c_chan *chan = data; + u32 val; + + if (state_high) { + val = LPC_READ_REG(chan, RGIO); + val |= GPIO_CLOCK; + LPC_WRITE_REG(chan, RGIO, val); + } else { + val = LPC_READ_REG(chan, RGIO); + val &= ~GPIO_CLOCK; + LPC_WRITE_REG(chan, RGIO, val); + val = LPC_READ_REG(chan, RGLVL); + val &= ~GPIO_CLOCK; + LPC_WRITE_REG(chan, RGLVL, val); + } +} + +static void set_data(void *data, int state_high) +{ + struct gma_i2c_chan *chan = data; + u32 val; + + if (state_high) { + val = LPC_READ_REG(chan, RGIO); + val |= GPIO_DATA; + LPC_WRITE_REG(chan, RGIO, val); + } else { + val = LPC_READ_REG(chan, RGIO); + val &= ~GPIO_DATA; + LPC_WRITE_REG(chan, RGIO, val); + val = LPC_READ_REG(chan, RGLVL); + val &= ~GPIO_DATA; + LPC_WRITE_REG(chan, RGLVL, val); + } +} + +struct gma_i2c_chan *oaktrail_lvds_i2c_init(struct drm_device *dev) +{ + struct drm_psb_private *dev_priv = to_drm_psb_private(dev); + struct gma_i2c_chan *chan; + int ret; + + chan = kzalloc(sizeof(struct gma_i2c_chan), GFP_KERNEL); + if (!chan) + return ERR_PTR(-ENOMEM); + + chan->drm_dev = dev; + chan->reg = dev_priv->lpc_gpio_base; + strncpy(chan->base.name, "gma500 LPC", I2C_NAME_SIZE - 1); + chan->base.owner = THIS_MODULE; + chan->base.algo_data = &chan->algo; + chan->base.dev.parent = dev->dev; + chan->algo.setsda = set_data; + chan->algo.setscl = set_clock; + chan->algo.getsda = get_data; + chan->algo.getscl = get_clock; + chan->algo.udelay = 100; + chan->algo.timeout = usecs_to_jiffies(2200); + chan->algo.data = chan; + + i2c_set_adapdata(&chan->base, chan); + + set_data(chan, 1); + set_clock(chan, 1); + udelay(50); + + ret = i2c_bit_add_bus(&chan->base); + if (ret < 0) { + kfree(chan); + return ERR_PTR(ret); + } + + return chan; +} |