/* * P2WI (Push-Pull Two Wire Interface) bus driver. * * Author: Boris BREZILLON <[email protected]> * * This file is licensed under the terms of the GNU General Public License * version 2. This program is licensed "as is" without any warranty of any * kind, whether express or implied. * * The P2WI controller looks like an SMBus controller which only supports byte * data transfers. But, it differs from standard SMBus protocol on several * aspects: * - it supports only one target device, and thus drop the address field * - it adds a parity bit every 8bits of data * - only one read access is required to read a byte (instead of a write * followed by a read access in standard SMBus protocol) * - there's no Ack bit after each byte transfer * * This means this bus cannot be used to interface with standard SMBus * devices (the only known device to support this interface is the AXP221 * PMIC). * */ #include <linux/clk.h> #include <linux/i2c.h> #include <linux/io.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> #include <linux/reset.h> /* P2WI registers */ #define P2WI_CTRL … #define P2WI_CCR … #define P2WI_INTE … #define P2WI_INTS … #define P2WI_DADDR0 … #define P2WI_DADDR1 … #define P2WI_DLEN … #define P2WI_DATA0 … #define P2WI_DATA1 … #define P2WI_LCR … #define P2WI_PMCR … /* CTRL fields */ #define P2WI_CTRL_START_TRANS … #define P2WI_CTRL_ABORT_TRANS … #define P2WI_CTRL_GLOBAL_INT_ENB … #define P2WI_CTRL_SOFT_RST … /* CLK CTRL fields */ #define P2WI_CCR_SDA_OUT_DELAY(v) … #define P2WI_CCR_MAX_CLK_DIV … #define P2WI_CCR_CLK_DIV(v) … /* STATUS fields */ #define P2WI_INTS_TRANS_ERR_ID(v) … #define P2WI_INTS_LOAD_BSY … #define P2WI_INTS_TRANS_ERR … #define P2WI_INTS_TRANS_OVER … /* DATA LENGTH fields*/ #define P2WI_DLEN_READ … #define P2WI_DLEN_DATA_LENGTH(v) … /* LINE CTRL fields*/ #define P2WI_LCR_SCL_STATE … #define P2WI_LCR_SDA_STATE … #define P2WI_LCR_SCL_CTL … #define P2WI_LCR_SCL_CTL_EN … #define P2WI_LCR_SDA_CTL … #define P2WI_LCR_SDA_CTL_EN … /* PMU MODE CTRL fields */ #define P2WI_PMCR_PMU_INIT_SEND … #define P2WI_PMCR_PMU_INIT_DATA(v) … #define P2WI_PMCR_PMU_MODE_REG(v) … #define P2WI_PMCR_PMU_DEV_ADDR(v) … #define P2WI_MAX_FREQ … struct p2wi { … }; static irqreturn_t p2wi_interrupt(int irq, void *dev_id) { … } static u32 p2wi_functionality(struct i2c_adapter *adap) { … } static int p2wi_smbus_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data *data) { … } static const struct i2c_algorithm p2wi_algo = …; static const struct of_device_id p2wi_of_match_table[] = …; MODULE_DEVICE_TABLE(of, p2wi_of_match_table); static int p2wi_probe(struct platform_device *pdev) { … } static void p2wi_remove(struct platform_device *dev) { … } static struct platform_driver p2wi_driver = …; module_platform_driver(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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