i2c/busses/i2c-microchip-corei2c.c

119 static void mchp_corei2c_core_disable(struct mchp_corei2c_dev *idev)
121 	u8 ctrl = readb(idev->base + CORE_I2C_CTRL);
124 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
127 static void mchp_corei2c_core_enable(struct mchp_corei2c_dev *idev)
129 	u8 ctrl = readb(idev->base + CORE_I2C_CTRL);
132 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
135 static void mchp_corei2c_reset(struct mchp_corei2c_dev *idev)
137 	mchp_corei2c_core_disable(idev);
138 	mchp_corei2c_core_enable(idev);
141 static inline void mchp_corei2c_stop(struct mchp_corei2c_dev *idev)
143 	u8 ctrl = readb(idev->base + CORE_I2C_CTRL);
146 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
150 					   struct mchp_corei2c_dev *idev)
173 	ctrl = readb(idev->base + CORE_I2C_CTRL);
176 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
178 	ctrl = readb(idev->base + CORE_I2C_CTRL);
185 static int mchp_corei2c_init(struct mchp_corei2c_dev *idev)
187 	u32 clk_rate = clk_get_rate(idev->i2c_clk);
188 	u32 divisor = clk_rate / idev->bus_clk_rate;
191 	ret = mchp_corei2c_set_divisor(divisor, idev);
195 	mchp_corei2c_reset(idev);
200 static void mchp_corei2c_empty_rx(struct mchp_corei2c_dev *idev)
204 	if (idev->msg_len > 0) {
205 		*idev->buf++ = readb(idev->base + CORE_I2C_DATA);
206 		idev->msg_len--;
209 	if (idev->msg_len <= 1) {
210 		ctrl = readb(idev->base + CORE_I2C_CTRL);
212 		writeb(ctrl, idev->base + CORE_I2C_CTRL);
216 static int mchp_corei2c_fill_tx(struct mchp_corei2c_dev *idev)
218 	if (idev->msg_len > 0)
219 		writeb(*idev->buf++, idev->base + CORE_I2C_DATA);
220 	idev->msg_len--;
225 static irqreturn_t mchp_corei2c_handle_isr(struct mchp_corei2c_dev *idev)
227 	u32 status = idev->isr_status;
231 	if (!idev->buf)
237 		ctrl = readb(idev->base + CORE_I2C_CTRL);
239 		writeb(idev->addr, idev->base + CORE_I2C_DATA);
240 		writeb(ctrl, idev->base + CORE_I2C_CTRL);
241 		if (idev->msg_len == 0)
245 		idev->msg_err = -EAGAIN;
250 		if (idev->msg_len > 0)
251 			mchp_corei2c_fill_tx(idev);
258 		idev->msg_err = -ENXIO;
262 		ctrl = readb(idev->base + CORE_I2C_CTRL);
263 		if (idev->msg_len == 1u) {
265 			writeb(ctrl, idev->base + CORE_I2C_CTRL);
268 			writeb(ctrl, idev->base + CORE_I2C_CTRL);
270 		if (idev->msg_len < 1u)
274 		mchp_corei2c_empty_rx(idev);
277 		mchp_corei2c_empty_rx(idev);
278 		if (idev->msg_len == 0)
287 		mchp_corei2c_stop(idev);
290 		complete(&idev->msg_complete);
297 	struct mchp_corei2c_dev *idev = _dev;
301 	ctrl = readb(idev->base + CORE_I2C_CTRL);
303 		idev->isr_status = readb(idev->base + CORE_I2C_STATUS);
304 		ret = mchp_corei2c_handle_isr(idev);
307 	ctrl = readb(idev->base + CORE_I2C_CTRL);
309 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
314 static int mchp_corei2c_xfer_msg(struct mchp_corei2c_dev *idev,
320 	idev->addr = i2c_8bit_addr_from_msg(msg);
321 	idev->msg_len = msg->len;
322 	idev->buf = msg->buf;
323 	idev->msg_err = 0;
325 	reinit_completion(&idev->msg_complete);
327 	mchp_corei2c_core_enable(idev);
329 	ctrl = readb(idev->base + CORE_I2C_CTRL);
331 	writeb(ctrl, idev->base + CORE_I2C_CTRL);
333 	time_left = wait_for_completion_timeout(&idev->msg_complete,
334 						idev->adapter.timeout);
338 	return idev->msg_err;
344 	struct mchp_corei2c_dev *idev = i2c_get_adapdata(adap);
348 		ret = mchp_corei2c_xfer_msg(idev, msgs++);
368 	struct mchp_corei2c_dev *idev;
372 	idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
373 	if (!idev)
376 	idev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
377 	if (IS_ERR(idev->base))
378 		return PTR_ERR(idev->base);
384 	idev->i2c_clk = devm_clk_get(&pdev->dev, NULL);
385 	if (IS_ERR(idev->i2c_clk))
386 		return dev_err_probe(&pdev->dev, PTR_ERR(idev->i2c_clk),
389 	idev->dev = &pdev->dev;
390 	init_completion(&idev->msg_complete);
392 	ret = device_property_read_u32(idev->dev, "clock-frequency",
393 				       &idev->bus_clk_rate);
394 	if (ret || !idev->bus_clk_rate) {
396 		idev->bus_clk_rate = 100000;
399 	if (idev->bus_clk_rate > 400000)
402 				     idev->bus_clk_rate);
410 			       pdev->name, idev);
415 	ret = clk_prepare_enable(idev->i2c_clk);
420 	ret = mchp_corei2c_init(idev);
422 		clk_disable_unprepare(idev->i2c_clk);
426 	i2c_set_adapdata(&idev->adapter, idev);
427 	snprintf(idev->adapter.name, sizeof(idev->adapter.name),
429 	idev->adapter.owner = THIS_MODULE;
430 	idev->adapter.algo = &mchp_corei2c_algo;
431 	idev->adapter.dev.parent = &pdev->dev;
432 	idev->adapter.dev.of_node = pdev->dev.of_node;
433 	idev->adapter.timeout = HZ;
435 	platform_set_drvdata(pdev, idev);
437 	ret = i2c_add_adapter(&idev->adapter);
439 		clk_disable_unprepare(idev->i2c_clk);
450 	struct mchp_corei2c_dev *idev = platform_get_drvdata(pdev);
452 	clk_disable_unprepare(idev->i2c_clk);
453 	i2c_del_adapter(&idev->adapter);