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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/gpu/drm/gma500/intel_i2c.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/gma500/intel_i2c.c')
-rw-r--r-- | drivers/gpu/drm/gma500/intel_i2c.c | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/drivers/gpu/drm/gma500/intel_i2c.c b/drivers/gpu/drm/gma500/intel_i2c.c new file mode 100644 index 000000000..9d02a7b6d --- /dev/null +++ b/drivers/gpu/drm/gma500/intel_i2c.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright © 2006-2007 Intel Corporation + * + * Authors: + * Eric Anholt <eric@anholt.net> + */ + +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/i2c-algo-bit.h> +#include <linux/i2c.h> + +#include "psb_drv.h" +#include "psb_intel_reg.h" + +/* + * Intel GPIO access functions + */ + +#define I2C_RISEFALL_TIME 20 + +static int get_clock(void *data) +{ + struct gma_i2c_chan *chan = data; + struct drm_device *dev = chan->drm_dev; + u32 val; + + val = REG_READ(chan->reg); + return (val & GPIO_CLOCK_VAL_IN) != 0; +} + +static int get_data(void *data) +{ + struct gma_i2c_chan *chan = data; + struct drm_device *dev = chan->drm_dev; + u32 val; + + val = REG_READ(chan->reg); + return (val & GPIO_DATA_VAL_IN) != 0; +} + +static void set_clock(void *data, int state_high) +{ + struct gma_i2c_chan *chan = data; + struct drm_device *dev = chan->drm_dev; + u32 reserved = 0, clock_bits; + + /* On most chips, these bits must be preserved in software. */ + reserved = + REG_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE | + GPIO_CLOCK_PULLUP_DISABLE); + + if (state_high) + clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK; + else + clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK | + GPIO_CLOCK_VAL_MASK; + REG_WRITE(chan->reg, reserved | clock_bits); + udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */ +} + +static void set_data(void *data, int state_high) +{ + struct gma_i2c_chan *chan = data; + struct drm_device *dev = chan->drm_dev; + u32 reserved = 0, data_bits; + + /* On most chips, these bits must be preserved in software. */ + reserved = + REG_READ(chan->reg) & (GPIO_DATA_PULLUP_DISABLE | + GPIO_CLOCK_PULLUP_DISABLE); + + if (state_high) + data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK; + else + data_bits = + GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK | + GPIO_DATA_VAL_MASK; + + REG_WRITE(chan->reg, reserved | data_bits); + udelay(I2C_RISEFALL_TIME); /* wait for the line to change state */ +} + +/** + * gma_i2c_create - instantiate an Intel i2c bus using the specified GPIO reg + * @dev: DRM device + * @reg: GPIO reg to use + * @name: name for this bus + * + * Creates and registers a new i2c bus with the Linux i2c layer, for use + * in output probing and control (e.g. DDC or SDVO control functions). + * + * Possible values for @reg include: + * %GPIOA + * %GPIOB + * %GPIOC + * %GPIOD + * %GPIOE + * %GPIOF + * %GPIOG + * %GPIOH + * see PRM for details on how these different busses are used. + */ +struct gma_i2c_chan *gma_i2c_create(struct drm_device *dev, const u32 reg, + const char *name) +{ + struct gma_i2c_chan *chan; + + chan = kzalloc(sizeof(struct gma_i2c_chan), GFP_KERNEL); + if (!chan) + goto out_free; + + chan->drm_dev = dev; + chan->reg = reg; + snprintf(chan->base.name, I2C_NAME_SIZE, "intel drm %s", name); + 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 = 20; + chan->algo.timeout = usecs_to_jiffies(2200); + chan->algo.data = chan; + + i2c_set_adapdata(&chan->base, chan); + + if (i2c_bit_add_bus(&chan->base)) + goto out_free; + + /* JJJ: raise SCL and SDA? */ + set_data(chan, 1); + set_clock(chan, 1); + udelay(20); + + return chan; + +out_free: + kfree(chan); + return NULL; +} + +/** + * gma_i2c_destroy - unregister and free i2c bus resources + * @chan: channel to free + * + * Unregister the adapter from the i2c layer, then free the structure. + */ +void gma_i2c_destroy(struct gma_i2c_chan *chan) +{ + if (!chan) + return; + + i2c_del_adapter(&chan->base); + kfree(chan); +} |