2  * Freescale MXS I2C bus driver
22 #include <linux/i2c.h>
32 #define DRIVER_NAME "mxs-i2c"
98  * struct mxs_i2c_dev - per device, private MXS-I2C data
104  * @adapter: i2c subsystem adapter node
116  * mxs_reset_block and the mach-dependency. Needs an I2C analyzer, probably.
118 static void mxs_i2c_reset(struct mxs_i2c_dev *i2c)  in mxs_i2c_reset()  argument
120 	mxs_reset_block(i2c->regs);  in mxs_i2c_reset()
121 	writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET);  in mxs_i2c_reset()
123 			i2c->regs + MXS_I2C_QUEUECTRL_SET);  in mxs_i2c_reset()
126 static void mxs_i2c_pioq_setup_read(struct mxs_i2c_dev *i2c, u8 addr, int len,  in mxs_i2c_pioq_setup_read()  argument
131 	writel(MXS_CMD_I2C_SELECT, i2c->regs + MXS_I2C_QUEUECMD);  in mxs_i2c_pioq_setup_read()
134 	writel(data, i2c->regs + MXS_I2C_DATA);  in mxs_i2c_pioq_setup_read()
137 	writel(data, i2c->regs + MXS_I2C_QUEUECMD);  in mxs_i2c_pioq_setup_read()
140 static void mxs_i2c_pioq_setup_write(struct mxs_i2c_dev *i2c,  in mxs_i2c_pioq_setup_write()  argument
147 	writel(data, i2c->regs + MXS_I2C_QUEUECMD);  in mxs_i2c_pioq_setup_write()
168 			writel(data, i2c->regs + MXS_I2C_DATA);  in mxs_i2c_pioq_setup_write()
174 		writel(data >> shifts_left, i2c->regs + MXS_I2C_DATA);  in mxs_i2c_pioq_setup_write()
181 static int mxs_i2c_wait_for_data(struct mxs_i2c_dev *i2c)  in mxs_i2c_wait_for_data()  argument
185 	while (readl(i2c->regs + MXS_I2C_QUEUESTAT)  in mxs_i2c_wait_for_data()
195 static int mxs_i2c_finish_read(struct mxs_i2c_dev *i2c, u8 *buf, int len)  in mxs_i2c_finish_read()  argument
202 			if (mxs_i2c_wait_for_data(i2c))  in mxs_i2c_finish_read()
204 			data = readl(i2c->regs + MXS_I2C_QUEUEDATA);  in mxs_i2c_finish_read()
219 	struct mxs_i2c_dev *i2c = i2c_get_adapdata(adap);  in mxs_i2c_xfer_msg()  local
223 	dev_dbg(i2c->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",  in mxs_i2c_xfer_msg()
229 	init_completion(&i2c->cmd_complete);  in mxs_i2c_xfer_msg()
234 		mxs_i2c_pioq_setup_read(i2c, msg->addr, msg->len, flags);  in mxs_i2c_xfer_msg()
236 		mxs_i2c_pioq_setup_write(i2c, msg->addr, msg->buf, msg->len,  in mxs_i2c_xfer_msg()
240 			i2c->regs + MXS_I2C_QUEUECTRL_SET);  in mxs_i2c_xfer_msg()
242 	ret = wait_for_completion_timeout(&i2c->cmd_complete,  in mxs_i2c_xfer_msg()
247 	if ((!i2c->cmd_err) && (msg->flags & I2C_M_RD)) {  in mxs_i2c_xfer_msg()
248 		ret = mxs_i2c_finish_read(i2c, msg->buf, msg->len);  in mxs_i2c_xfer_msg()
253 	if (i2c->cmd_err == -ENXIO)  in mxs_i2c_xfer_msg()
254 		mxs_i2c_reset(i2c);  in mxs_i2c_xfer_msg()
256 	dev_dbg(i2c->dev, "Done with err=%d\n", i2c->cmd_err);  in mxs_i2c_xfer_msg()
258 	return i2c->cmd_err;  in mxs_i2c_xfer_msg()
261 	dev_dbg(i2c->dev, "Timeout!\n");  in mxs_i2c_xfer_msg()
262 	mxs_i2c_reset(i2c);  in mxs_i2c_xfer_msg()
288 	struct mxs_i2c_dev *i2c = dev_id;  in mxs_i2c_isr()  local
289 	u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK;  in mxs_i2c_isr()
296 		i2c->cmd_err = -ENXIO;  in mxs_i2c_isr()
301 		i2c->cmd_err = -EIO;  in mxs_i2c_isr()
303 		i2c->cmd_err = 0;  in mxs_i2c_isr()
305 	is_last_cmd = (readl(i2c->regs + MXS_I2C_QUEUESTAT) &  in mxs_i2c_isr()
308 	if (is_last_cmd || i2c->cmd_err)  in mxs_i2c_isr()
309 		complete(&i2c->cmd_complete);  in mxs_i2c_isr()
311 	writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR);  in mxs_i2c_isr()
324 	struct mxs_i2c_dev *i2c;  in mxs_i2c_probe()  local
330 	i2c = devm_kzalloc(dev, sizeof(struct mxs_i2c_dev), GFP_KERNEL);  in mxs_i2c_probe()
331 	if (!i2c)  in mxs_i2c_probe()
342 	i2c->regs = devm_ioremap_nocache(dev, res->start, res_size);  in mxs_i2c_probe()
343 	if (!i2c->regs)  in mxs_i2c_probe()
350 	err = devm_request_irq(dev, irq, mxs_i2c_isr, 0, dev_name(dev), i2c);  in mxs_i2c_probe()
354 	i2c->dev = dev;  in mxs_i2c_probe()
355 	platform_set_drvdata(pdev, i2c);  in mxs_i2c_probe()
358 	mxs_i2c_reset(i2c);  in mxs_i2c_probe()
360 	adap = &i2c->adapter;  in mxs_i2c_probe()
361 	strlcpy(adap->name, "MXS I2C adapter", sizeof(adap->name));  in mxs_i2c_probe()
366 	i2c_set_adapdata(adap, i2c);  in mxs_i2c_probe()
371 				i2c->regs + MXS_I2C_CTRL0_SET);  in mxs_i2c_probe()
380 	struct mxs_i2c_dev *i2c = platform_get_drvdata(pdev);  in mxs_i2c_remove()  local
383 	ret = i2c_del_adapter(&i2c->adapter);  in mxs_i2c_remove()
388 			i2c->regs + MXS_I2C_QUEUECTRL_CLR);  in mxs_i2c_remove()
389 	writel(MXS_I2C_CTRL0_SFTRST, i2c->regs + MXS_I2C_CTRL0_SET);  in mxs_i2c_remove()
417 MODULE_DESCRIPTION("MXS I2C Bus Driver");