i2c/busses/i2c-lpc2k.c

5  * Code portions referenced from the i2x-pxa and i2c-pnx drivers
17 #include <linux/i2c.h>
83 static void i2c_lpc2k_reset(struct lpc2k_i2c *i2c)
86 	writel(LPC24XX_CLEAR_ALL, i2c->base + LPC24XX_I2CONCLR);
87 	writel(0, i2c->base + LPC24XX_I2ADDR);
88 	writel(LPC24XX_I2EN, i2c->base + LPC24XX_I2CONSET);
91 static int i2c_lpc2k_clear_arb(struct lpc2k_i2c *i2c)
99 	writel(LPC24XX_STO, i2c->base + LPC24XX_I2CONSET);
102 	while (readl(i2c->base + LPC24XX_I2STAT) != M_I2C_IDLE) {
105 			i2c_lpc2k_reset(i2c);
115 static void i2c_lpc2k_pump_msg(struct lpc2k_i2c *i2c)
124 	status = readl(i2c->base + LPC24XX_I2STAT);
130 		data = i2c_8bit_addr_from_msg(i2c->msg);
132 		writel(data, i2c->base + LPC24XX_I2DAT);
133 		writel(LPC24XX_STA, i2c->base + LPC24XX_I2CONCLR);
142 		if (i2c->msg_idx < i2c->msg->len) {
143 			writel(i2c->msg->buf[i2c->msg_idx],
144 			       i2c->base + LPC24XX_I2DAT);
145 		} else if (i2c->is_last) {
147 			writel(LPC24XX_STO_AA, i2c->base + LPC24XX_I2CONSET);
148 			writel(LPC24XX_SI, i2c->base + LPC24XX_I2CONCLR);
149 			i2c->msg_status = 0;
150 			disable_irq_nosync(i2c->irq);
152 			i2c->msg_status = 0;
153 			disable_irq_nosync(i2c->irq);
156 		i2c->msg_idx++;
161 		if (i2c->msg->len == 1) {
163 			writel(LPC24XX_AA, i2c->base + LPC24XX_I2CONCLR);
166 			writel(LPC24XX_AA, i2c->base + LPC24XX_I2CONSET);
169 		writel(LPC24XX_STA, i2c->base + LPC24XX_I2CONCLR);
180 		if (i2c->msg_idx < i2c->msg->len) {
181 			i2c->msg->buf[i2c->msg_idx] =
182 					readl(i2c->base + LPC24XX_I2DAT);
186 		if (i2c->msg_idx >= i2c->msg->len - 1 && i2c->is_last) {
187 			writel(LPC24XX_STO_AA, i2c->base + LPC24XX_I2CONSET);
188 			writel(LPC24XX_SI, i2c->base + LPC24XX_I2CONCLR);
189 			i2c->msg_status = 0;
193 		if (i2c->msg_idx >= i2c->msg->len - 1) {
194 			i2c->msg_status = 0;
195 			disable_irq_nosync(i2c->irq);
202 		if (i2c->msg_idx >= i2c->msg->len - 2) {
204 			writel(LPC24XX_AA, i2c->base + LPC24XX_I2CONCLR);
207 			writel(LPC24XX_AA, i2c->base + LPC24XX_I2CONSET);
210 		writel(LPC24XX_STA, i2c->base + LPC24XX_I2CONCLR);
211 		i2c->msg_idx++;
218 		writel(LPC24XX_STO_AA, i2c->base + LPC24XX_I2CONSET);
219 		i2c->msg_status = -ENXIO;
220 		disable_irq_nosync(i2c->irq);
225 		i2c->msg_status = -EAGAIN;
228 		writel(LPC24XX_STA | LPC24XX_STO, i2c->base + LPC24XX_I2CONCLR);
229 		disable_irq_nosync(i2c->irq);
234 		i2c->msg_status = -EIO;
235 		disable_irq_nosync(i2c->irq);
240 	if (i2c->msg_status != -EBUSY)
241 		wake_up(&i2c->wait);
247 	if (i2c->msg_status != 0)
248 		writel(LPC24XX_SI, i2c->base + LPC24XX_I2CONCLR);
251 static int lpc2k_process_msg(struct lpc2k_i2c *i2c, int msgidx)
255 		writel(LPC24XX_STA, i2c->base + LPC24XX_I2CONSET);
262 		if (unlikely(i2c->msg->flags & I2C_M_NOSTART)) {
263 			WARN_ON(i2c->msg->len == 0);
265 			if (!(i2c->msg->flags & I2C_M_RD)) {
267 				writel(i2c->msg->buf[0],
268 				       i2c->base + LPC24XX_I2DAT);
269 				i2c->msg_idx++;
273 			writel(LPC24XX_STA, i2c->base + LPC24XX_I2CONSET);
276 		writel(LPC24XX_SI, i2c->base + LPC24XX_I2CONCLR);
279 	enable_irq(i2c->irq);
282 	if (wait_event_timeout(i2c->wait, i2c->msg_status != -EBUSY,
284 		disable_irq_nosync(i2c->irq);
289 	return i2c->msg_status;
295 	struct lpc2k_i2c *i2c = i2c_get_adapdata(adap);
300 	stat = readl(i2c->base + LPC24XX_I2STAT);
303 		return i2c_lpc2k_clear_arb(i2c);
309 		i2c->msg = &msgs[i];
310 		i2c->msg_idx = 0;
311 		i2c->msg_status = -EBUSY;
312 		i2c->is_last = (i == (msg_num - 1));
314 		ret = lpc2k_process_msg(i2c, i);
324 	struct lpc2k_i2c *i2c = dev_id;
326 	if (readl(i2c->base + LPC24XX_I2CONSET) & LPC24XX_SI) {
327 		i2c_lpc2k_pump_msg(i2c);
347 	struct lpc2k_i2c *i2c;
353 	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
354 	if (!i2c)
357 	i2c->base = devm_platform_ioremap_resource(pdev, 0);
358 	if (IS_ERR(i2c->base))
359 		return PTR_ERR(i2c->base);
361 	i2c->irq = platform_get_irq(pdev, 0);
362 	if (i2c->irq < 0)
363 		return i2c->irq;
365 	init_waitqueue_head(&i2c->wait);
367 	i2c->clk = devm_clk_get_enabled(&pdev->dev, NULL);
368 	if (IS_ERR(i2c->clk)) {
370 		return PTR_ERR(i2c->clk);
373 	ret = devm_request_irq(&pdev->dev, i2c->irq, i2c_lpc2k_handler, 0,
374 			       dev_name(&pdev->dev), i2c);
380 	disable_irq_nosync(i2c->irq);
383 	i2c_lpc2k_reset(i2c);
390 	clkrate = clk_get_rate(i2c->clk);
405 	writel(scl_high, i2c->base + LPC24XX_I2SCLH);
406 	writel(clkrate - scl_high, i2c->base + LPC24XX_I2SCLL);
408 	platform_set_drvdata(pdev, i2c);
410 	i2c_set_adapdata(&i2c->adap, i2c);
411 	i2c->adap.owner = THIS_MODULE;
412 	strscpy(i2c->adap.name, "LPC2K I2C adapter", sizeof(i2c->adap.name));
413 	i2c->adap.algo = &i2c_lpc2k_algorithm;
414 	i2c->adap.dev.parent = &pdev->dev;
415 	i2c->adap.dev.of_node = pdev->dev.of_node;
417 	ret = i2c_add_adapter(&i2c->adap);
428 	struct lpc2k_i2c *i2c = platform_get_drvdata(dev);
430 	i2c_del_adapter(&i2c->adap);
435 	struct lpc2k_i2c *i2c = dev_get_drvdata(dev);
437 	clk_disable(i2c->clk);
444 	struct lpc2k_i2c *i2c = dev_get_drvdata(dev);
446 	clk_enable(i2c->clk);
447 	i2c_lpc2k_reset(i2c);
458 	{ .compatible = "nxp,lpc1788-i2c" },
467 		.name		= "lpc2k-i2c",
477 MODULE_ALIAS("platform:lpc2k-i2c");