/* * Copyright © 2009 Keith Packard * * Permission to use, copy, modify, distribute, and sell this software and its * documentation for any purpose is hereby granted without fee, provided that * the above copyright notice appear in all copies and that both that copyright * notice and this permission notice appear in supporting documentation, and * that the name of the copyright holders not be used in advertising or * publicity pertaining to distribution of the software without specific, * written prior permission. The copyright holders make no representations * about the suitability of this software for any purpose. It is provided "as * is" without express or implied warranty. * * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE * OF THIS SOFTWARE. * * $FreeBSD: head/sys/dev/drm2/drm_dp_iic_helper.c 249249 2013-04-08 08:37:57Z dumbbell $ */ #include #include #include #include #include "iicbus_if.h" #include #include #include static int iic_dp_aux_transaction(device_t idev, int mode, uint8_t write_byte, uint8_t *read_byte) { struct i2c_algo_dp_aux_data *aux_data; int ret; aux_data = device_get_softc(idev); ret = (*aux_data->aux_ch)(idev, mode, write_byte, read_byte); return (ret); } /* * I2C over AUX CH */ /* * Send the address. If the I2C link is running, this 'restarts' * the connection with the new address, this is used for doing * a write followed by a read (as needed for DDC) */ static int iic_dp_aux_address(device_t idev, u16 address, bool reading) { struct i2c_algo_dp_aux_data *aux_data; int mode, ret; aux_data = device_get_softc(idev); mode = MODE_I2C_START; if (reading) mode |= MODE_I2C_READ; else mode |= MODE_I2C_WRITE; aux_data->address = address; aux_data->running = true; ret = iic_dp_aux_transaction(idev, mode, 0, NULL); return (ret); } /* * Stop the I2C transaction. This closes out the link, sending * a bare address packet with the MOT bit turned off */ static void iic_dp_aux_stop(device_t idev, bool reading) { struct i2c_algo_dp_aux_data *aux_data; int mode; aux_data = device_get_softc(idev); mode = MODE_I2C_STOP; if (reading) mode |= MODE_I2C_READ; else mode |= MODE_I2C_WRITE; if (aux_data->running) { (void)iic_dp_aux_transaction(idev, mode, 0, NULL); aux_data->running = false; } } /* * Write a single byte to the current I2C address, the * the I2C link must be running or this returns -EIO */ static int iic_dp_aux_put_byte(device_t idev, u8 byte) { struct i2c_algo_dp_aux_data *aux_data; int ret; aux_data = device_get_softc(idev); if (!aux_data->running) return (EIO); ret = iic_dp_aux_transaction(idev, MODE_I2C_WRITE, byte, NULL); return (ret); } /* * Read a single byte from the current I2C address, the * I2C link must be running or this returns -EIO */ static int iic_dp_aux_get_byte(device_t idev, u8 *byte_ret) { struct i2c_algo_dp_aux_data *aux_data; int ret; aux_data = device_get_softc(idev); if (!aux_data->running) return (EIO); ret = iic_dp_aux_transaction(idev, MODE_I2C_READ, 0, byte_ret); return (ret); } static int iic_dp_aux_xfer(device_t idev, struct iic_msg *msgs, uint32_t num) { u8 *buf; int b, m, ret; u16 len; bool reading; ret = 0; reading = false; for (m = 0; m < num; m++) { len = msgs[m].len; buf = msgs[m].buf; reading = (msgs[m].flags & IIC_M_RD) != 0; ret = iic_dp_aux_address(idev, msgs[m].slave >> 1, reading); if (ret != 0) break; if (reading) { for (b = 0; b < len; b++) { ret = iic_dp_aux_get_byte(idev, &buf[b]); if (ret != 0) break; } } else { for (b = 0; b < len; b++) { ret = iic_dp_aux_put_byte(idev, buf[b]); if (ret != 0) break; } } if (ret != 0) break; } iic_dp_aux_stop(idev, reading); DRM_DEBUG_KMS("dp_aux_xfer return %d\n", ret); return (ret); } static void iic_dp_aux_reset_bus(device_t idev) { (void)iic_dp_aux_address(idev, 0, false); (void)iic_dp_aux_stop(idev, false); } static int iic_dp_aux_reset(device_t idev, u_char speed, u_char addr, u_char *oldaddr) { iic_dp_aux_reset_bus(idev); return (0); } static int iic_dp_aux_prepare_bus(device_t idev) { /* adapter->retries = 3; */ iic_dp_aux_reset_bus(idev); return (0); } static int iic_dp_aux_probe(device_t idev) { return (BUS_PROBE_DEFAULT); } static int iic_dp_aux_attach(device_t idev) { struct i2c_algo_dp_aux_data *aux_data; aux_data = device_get_softc(idev); aux_data->port = device_add_child(idev, "iicbus", -1); if (aux_data->port == NULL) return (ENXIO); device_quiet(aux_data->port); bus_generic_attach(idev); return (0); } int iic_dp_aux_add_bus(device_t dev, const char *name, int (*ch)(device_t idev, int mode, uint8_t write_byte, uint8_t *read_byte), void *priv, device_t *bus, device_t *adapter) { device_t ibus; struct i2c_algo_dp_aux_data *data; int idx, error; static int dp_bus_counter; idx = atomic_fetchadd_int(&dp_bus_counter, 1); ibus = device_add_child(dev, "drm_iic_dp_aux", idx); if (ibus == NULL) { DRM_ERROR("drm_iic_dp_aux bus %d creation error\n", idx); return (-ENXIO); } device_quiet(ibus); error = device_probe_and_attach(ibus); if (error != 0) { device_delete_child(dev, ibus); DRM_ERROR("drm_iic_dp_aux bus %d attach failed, %d\n", idx, error); return (-error); } data = device_get_softc(ibus); data->running = false; data->address = 0; data->aux_ch = ch; data->priv = priv; error = iic_dp_aux_prepare_bus(ibus); if (error == 0) { *bus = ibus; *adapter = data->port; } return (error); } static device_method_t drm_iic_dp_aux_methods[] = { DEVMETHOD(device_probe, iic_dp_aux_probe), DEVMETHOD(device_attach, iic_dp_aux_attach), DEVMETHOD(device_detach, bus_generic_detach), DEVMETHOD(iicbus_reset, iic_dp_aux_reset), DEVMETHOD(iicbus_transfer, iic_dp_aux_xfer), DEVMETHOD_END }; static driver_t drm_iic_dp_aux_driver = { "drm_iic_dp_aux", drm_iic_dp_aux_methods, sizeof(struct i2c_algo_dp_aux_data) }; static devclass_t drm_iic_dp_aux_devclass; DRIVER_MODULE_ORDERED(drm_iic_dp_aux, drm, drm_iic_dp_aux_driver, drm_iic_dp_aux_devclass, NULL, NULL, SI_ORDER_SECOND);