diff options
Diffstat (limited to 'drivers/staging/go7007/go7007-i2c.c')
| -rw-r--r-- | drivers/staging/go7007/go7007-i2c.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/drivers/staging/go7007/go7007-i2c.c b/drivers/staging/go7007/go7007-i2c.c new file mode 100644 index 00000000000..10baae3dade --- /dev/null +++ b/drivers/staging/go7007/go7007-i2c.c @@ -0,0 +1,309 @@ +/* + * Copyright (C) 2005-2006 Micronas USA Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License (Version 2) as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. + */ + +#include <linux/version.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/sched.h> +#include <linux/list.h> +#include <linux/unistd.h> +#include <linux/time.h> +#include <linux/device.h> +#include <linux/i2c.h> +#include <linux/semaphore.h> +#include <linux/uaccess.h> +#include <asm/system.h> + +#include "go7007-priv.h" +#include "wis-i2c.h" + +/************** Registration interface for I2C client drivers **************/ + +/* Since there's no way to auto-probe the I2C devices connected to the I2C + * bus on the go7007, we have this silly little registration system that + * client drivers can use to register their I2C driver ID and their + * detect_client function (the one that's normally passed to i2c_probe). + * + * When a new go7007 device is connected, we can look up in a board info + * table by the USB or PCI vendor/product/revision ID to determine + * which I2C client module to load. The client driver module will register + * itself here, and then we can call the registered detect_client function + * to force-load a new client at the address listed in the board info table. + * + * Really the I2C subsystem should have a way to force-load I2C client + * drivers when we have a priori knowledge of what's on the bus, especially + * since the existing I2C auto-probe mechanism is so hokey, but we'll use + * our own mechanism for the time being. */ + +struct wis_i2c_client_driver { + unsigned int id; + found_proc found_proc; + struct list_head list; +}; + +static LIST_HEAD(i2c_client_drivers); +static DECLARE_MUTEX(i2c_client_driver_list_lock); + +/* Client drivers register here by their I2C driver ID */ +int wis_i2c_add_driver(unsigned int id, found_proc found_proc) +{ + struct wis_i2c_client_driver *driver; + + driver = kmalloc(sizeof(struct wis_i2c_client_driver), GFP_KERNEL); + if (driver == NULL) + return -ENOMEM; + driver->id = id; + driver->found_proc = found_proc; + + down(&i2c_client_driver_list_lock); + list_add_tail(&driver->list, &i2c_client_drivers); + up(&i2c_client_driver_list_lock); + + return 0; +} +EXPORT_SYMBOL(wis_i2c_add_driver); + +void wis_i2c_del_driver(found_proc found_proc) +{ + struct wis_i2c_client_driver *driver, *next; + + down(&i2c_client_driver_list_lock); + list_for_each_entry_safe(driver, next, &i2c_client_drivers, list) + if (driver->found_proc == found_proc) { + list_del(&driver->list); + kfree(driver); + } + up(&i2c_client_driver_list_lock); +} +EXPORT_SYMBOL(wis_i2c_del_driver); + +/* The main go7007 driver calls this to instantiate a client by driver + * ID and bus address, which are both stored in the board info table */ +int wis_i2c_probe_device(struct i2c_adapter *adapter, + unsigned int id, int addr) +{ + struct wis_i2c_client_driver *driver; + int found = 0; + + if (addr < 0 || addr > 0x7f) + return -1; + down(&i2c_client_driver_list_lock); + list_for_each_entry(driver, &i2c_client_drivers, list) + if (driver->id == id) { + if (driver->found_proc(adapter, addr, 0) == 0) + found = 1; + break; + } + up(&i2c_client_driver_list_lock); + return found; +} + +/********************* Driver for on-board I2C adapter *********************/ + +/* #define GO7007_I2C_DEBUG */ + +#define SPI_I2C_ADDR_BASE 0x1400 +#define STATUS_REG_ADDR (SPI_I2C_ADDR_BASE + 0x2) +#define I2C_CTRL_REG_ADDR (SPI_I2C_ADDR_BASE + 0x6) +#define I2C_DEV_UP_ADDR_REG_ADDR (SPI_I2C_ADDR_BASE + 0x7) +#define I2C_LO_ADDR_REG_ADDR (SPI_I2C_ADDR_BASE + 0x8) +#define I2C_DATA_REG_ADDR (SPI_I2C_ADDR_BASE + 0x9) +#define I2C_CLKFREQ_REG_ADDR (SPI_I2C_ADDR_BASE + 0xa) + +#define I2C_STATE_MASK 0x0007 +#define I2C_READ_READY_MASK 0x0008 + +/* There is only one I2C port on the TW2804 that feeds all four GO7007 VIPs + * on the Adlink PCI-MPG24, so access is shared between all of them. */ +static DECLARE_MUTEX(adlink_mpg24_i2c_lock); + +static int go7007_i2c_xfer(struct go7007 *go, u16 addr, int read, + u16 command, int flags, u8 *data) +{ + int i, ret = -1; + u16 val; + + if (go->status == STATUS_SHUTDOWN) + return -1; + +#ifdef GO7007_I2C_DEBUG + if (read) + printk(KERN_DEBUG "go7007-i2c: reading 0x%02x on 0x%02x\n", + command, addr); + else + printk(KERN_DEBUG + "go7007-i2c: writing 0x%02x to 0x%02x on 0x%02x\n", + *data, command, addr); +#endif + + down(&go->hw_lock); + + if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) { + /* Bridge the I2C port on this GO7007 to the shared bus */ + down(&adlink_mpg24_i2c_lock); + go7007_write_addr(go, 0x3c82, 0x0020); + } + + /* Wait for I2C adapter to be ready */ + for (i = 0; i < 10; ++i) { + if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0) + goto i2c_done; + if (!(val & I2C_STATE_MASK)) + break; + msleep(100); + } + if (i == 10) { + printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n"); + goto i2c_done; + } + + /* Set target register (command) */ + go7007_write_addr(go, I2C_CTRL_REG_ADDR, flags); + go7007_write_addr(go, I2C_LO_ADDR_REG_ADDR, command); + + /* If we're writing, send the data and target address and we're done */ + if (!read) { + go7007_write_addr(go, I2C_DATA_REG_ADDR, *data); + go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR, + (addr << 9) | (command >> 8)); + ret = 0; + goto i2c_done; + } + + /* Otherwise, we're reading. First clear i2c_rx_data_rdy. */ + if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0) + goto i2c_done; + + /* Send the target address plus read flag */ + go7007_write_addr(go, I2C_DEV_UP_ADDR_REG_ADDR, + (addr << 9) | 0x0100 | (command >> 8)); + + /* Wait for i2c_rx_data_rdy */ + for (i = 0; i < 10; ++i) { + if (go7007_read_addr(go, STATUS_REG_ADDR, &val) < 0) + goto i2c_done; + if (val & I2C_READ_READY_MASK) + break; + msleep(100); + } + if (i == 10) { + printk(KERN_ERR "go7007-i2c: I2C adapter is hung\n"); + goto i2c_done; + } + + /* Retrieve the read byte */ + if (go7007_read_addr(go, I2C_DATA_REG_ADDR, &val) < 0) + goto i2c_done; + *data = val; + ret = 0; + +i2c_done: + if (go->board_id == GO7007_BOARDID_ADLINK_MPG24) { + /* Isolate the I2C port on this GO7007 from the shared bus */ + go7007_write_addr(go, 0x3c82, 0x0000); + up(&adlink_mpg24_i2c_lock); + } + up(&go->hw_lock); + return ret; +} + +static int go7007_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, union i2c_smbus_data *data) +{ + struct go7007 *go = i2c_get_adapdata(adapter); + + if (size != I2C_SMBUS_BYTE_DATA) + return -1; + return go7007_i2c_xfer(go, addr, read_write == I2C_SMBUS_READ, command, + flags & I2C_CLIENT_SCCB ? 0x10 : 0x00, &data->byte); +} + +/* VERY LIMITED I2C master xfer function -- only needed because the + * SMBus functions only support 8-bit commands and the SAA7135 uses + * 16-bit commands. The I2C interface on the GO7007, as limited as + * it is, does support this mode. */ + +static int go7007_i2c_master_xfer(struct i2c_adapter *adapter, + struct i2c_msg msgs[], int num) +{ + struct go7007 *go = i2c_get_adapdata(adapter); + int i; + + for (i = 0; i < num; ++i) { + /* We can only do two things here -- write three bytes, or + * write two bytes and read one byte. */ + if (msgs[i].len == 2) { + if (i + 1 == num || msgs[i].addr != msgs[i + 1].addr || + (msgs[i].flags & I2C_M_RD) || + !(msgs[i + 1].flags & I2C_M_RD) || + msgs[i + 1].len != 1) + return -1; + if (go7007_i2c_xfer(go, msgs[i].addr, 1, + (msgs[i].buf[0] << 8) | msgs[i].buf[1], + 0x01, &msgs[i + 1].buf[0]) < 0) + return -1; + ++i; + } else if (msgs[i].len == 3) { + if (msgs[i].flags & I2C_M_RD) + return -1; + if (msgs[i].len != 3) + return -1; + if (go7007_i2c_xfer(go, msgs[i].addr, 0, + (msgs[i].buf[0] << 8) | msgs[i].buf[1], + 0x01, &msgs[i].buf[2]) < 0) + return -1; + } else + return -1; + } + + return 0; +} + +static u32 go7007_functionality(struct i2c_adapter *adapter) +{ + return I2C_FUNC_SMBUS_BYTE_DATA; +} + +static struct i2c_algorithm go7007_algo = { + .smbus_xfer = go7007_smbus_xfer, + .master_xfer = go7007_i2c_master_xfer, + .functionality = go7007_functionality, +}; + +static struct i2c_adapter go7007_adap_templ = { + .owner = THIS_MODULE, + .class = I2C_CLASS_TV_ANALOG, + .name = "WIS GO7007SB", + .id = I2C_ALGO_GO7007, + .algo = &go7007_algo, +}; + +int go7007_i2c_init(struct go7007 *go) +{ + memcpy(&go->i2c_adapter, &go7007_adap_templ, + sizeof(go7007_adap_templ)); + go->i2c_adapter.dev.parent = go->dev; + i2c_set_adapdata(&go->i2c_adapter, go); + if (i2c_add_adapter(&go->i2c_adapter) < 0) { + printk(KERN_ERR + "go7007-i2c: error: i2c_add_adapter failed\n"); + return -1; + } + return 0; +} |