3 // Apple SoC SPI device driver
7 // Based on spi-sifive.c, Copyright 2018 SiFive, Inc.
18 #include <linux/spi/spi.h>
129 static inline void reg_write(struct apple_spi *spi, int offset, u32 value)  in reg_write()  argument
131 	writel_relaxed(value, spi->regs + offset);  in reg_write()
134 static inline u32 reg_read(struct apple_spi *spi, int offset)  in reg_read()  argument
136 	return readl_relaxed(spi->regs + offset);  in reg_read()
139 static inline void reg_mask(struct apple_spi *spi, int offset, u32 clear, u32 set)  in reg_mask()  argument
141 	u32 val = reg_read(spi, offset);  in reg_mask()
145 	reg_write(spi, offset, val);  in reg_mask()
148 static void apple_spi_init(struct apple_spi *spi)  in apple_spi_init()  argument
151 	reg_write(spi, APPLE_SPI_PIN, APPLE_SPI_PIN_CS);  in apple_spi_init()
152 	reg_mask(spi, APPLE_SPI_SHIFTCFG, APPLE_SPI_SHIFTCFG_OVERRIDE_CS, 0);  in apple_spi_init()
153 	reg_mask(spi, APPLE_SPI_PINCFG, APPLE_SPI_PINCFG_CS_IDLE_VAL, APPLE_SPI_PINCFG_KEEP_CS);  in apple_spi_init()
156 	reg_write(spi, APPLE_SPI_CTRL, APPLE_SPI_CTRL_RX_RESET | APPLE_SPI_CTRL_TX_RESET);  in apple_spi_init()
159 	reg_write(spi, APPLE_SPI_CFG,  in apple_spi_init()
165 	reg_write(spi, APPLE_SPI_IE_FIFO, 0);  in apple_spi_init()
166 	reg_write(spi, APPLE_SPI_IE_XFER, 0);  in apple_spi_init()
169 	reg_write(spi, APPLE_SPI_DELAY_PRE, 0);  in apple_spi_init()
170 	reg_write(spi, APPLE_SPI_DELAY_POST, 0);  in apple_spi_init()
175 	struct apple_spi *spi = spi_controller_get_devdata(ctlr);  in apple_spi_prepare_message()  local
176 	struct spi_device *device = msg->spi;  in apple_spi_prepare_message()
183 	reg_mask(spi, APPLE_SPI_CFG,  in apple_spi_prepare_message()
191 	struct apple_spi *spi = spi_controller_get_devdata(device->controller);  in apple_spi_set_cs()  local
193 	reg_mask(spi, APPLE_SPI_PIN, APPLE_SPI_PIN_CS, is_high ? APPLE_SPI_PIN_CS : 0);  in apple_spi_set_cs()
196 static bool apple_spi_prep_transfer(struct apple_spi *spi, struct spi_transfer *t)  in apple_spi_prep_transfer()  argument
201 	cr = DIV_ROUND_UP(clk_get_rate(spi->clk), t->speed_hz);  in apple_spi_prep_transfer()
202 	reg_write(spi, APPLE_SPI_CLKDIV, min_t(u32, cr, APPLE_SPI_CLKDIV_MAX));  in apple_spi_prep_transfer()
205 	reg_mask(spi, APPLE_SPI_SHIFTCFG, APPLE_SPI_SHIFTCFG_BITS,  in apple_spi_prep_transfer()
220 	struct apple_spi *spi = dev_id;  in apple_spi_irq()  local
221 	u32 fifo = reg_read(spi, APPLE_SPI_IF_FIFO) & reg_read(spi, APPLE_SPI_IE_FIFO);  in apple_spi_irq()
222 	u32 xfer = reg_read(spi, APPLE_SPI_IF_XFER) & reg_read(spi, APPLE_SPI_IE_XFER);  in apple_spi_irq()
226 		reg_write(spi, APPLE_SPI_IE_XFER, 0);  in apple_spi_irq()
227 		reg_write(spi, APPLE_SPI_IE_FIFO, 0);  in apple_spi_irq()
228 		complete(&spi->done);  in apple_spi_irq()
235 static int apple_spi_wait(struct apple_spi *spi, u32 fifo_bit, u32 xfer_bit, int poll)  in apple_spi_wait()  argument
244 			fifo = reg_read(spi, APPLE_SPI_IF_FIFO);  in apple_spi_wait()
245 			xfer = reg_read(spi, APPLE_SPI_IF_XFER);  in apple_spi_wait()
252 		reinit_completion(&spi->done);  in apple_spi_wait()
253 		reg_write(spi, APPLE_SPI_IE_XFER, xfer_bit);  in apple_spi_wait()
254 		reg_write(spi, APPLE_SPI_IE_FIFO, fifo_bit);  in apple_spi_wait()
256 		if (!wait_for_completion_timeout(&spi->done,  in apple_spi_wait()
260 		reg_write(spi, APPLE_SPI_IE_XFER, 0);  in apple_spi_wait()
261 		reg_write(spi, APPLE_SPI_IE_FIFO, 0);  in apple_spi_wait()
267 static void apple_spi_tx(struct apple_spi *spi, const void **tx_ptr, u32 *left,  in apple_spi_tx()  argument
275 	inuse = FIELD_GET(APPLE_SPI_FIFOSTAT_LEVEL_TX, reg_read(spi, APPLE_SPI_FIFOSTAT));  in apple_spi_tx()
288 			reg_write(spi, APPLE_SPI_TXDATA, *p++);  in apple_spi_tx()
295 			reg_write(spi, APPLE_SPI_TXDATA, *p++);  in apple_spi_tx()
302 			reg_write(spi, APPLE_SPI_TXDATA, *p++);  in apple_spi_tx()
312 static void apple_spi_rx(struct apple_spi *spi, void **rx_ptr, u32 *left,  in apple_spi_rx()  argument
320 	words = read = FIELD_GET(APPLE_SPI_FIFOSTAT_LEVEL_RX, reg_read(spi, APPLE_SPI_FIFOSTAT));  in apple_spi_rx()
333 			*p++ = reg_read(spi, APPLE_SPI_RXDATA);  in apple_spi_rx()
340 			*p++ = reg_read(spi, APPLE_SPI_RXDATA);  in apple_spi_rx()
347 			*p++ = reg_read(spi, APPLE_SPI_RXDATA);  in apple_spi_rx()
360 	struct apple_spi *spi = spi_controller_get_devdata(ctlr);  in apple_spi_transfer_one()  local
361 	bool poll = apple_spi_prep_transfer(spi, t);  in apple_spi_transfer_one()
383 	reg_write(spi, APPLE_SPI_CTRL, APPLE_SPI_CTRL_RX_RESET | APPLE_SPI_CTRL_TX_RESET);  in apple_spi_transfer_one()
386 	reg_write(spi, APPLE_SPI_IF_XFER, ~0);  in apple_spi_transfer_one()
387 	reg_write(spi, APPLE_SPI_IF_FIFO, ~0);  in apple_spi_transfer_one()
396 	reg_write(spi, APPLE_SPI_TXCNT, remaining_tx);  in apple_spi_transfer_one()
397 	reg_write(spi, APPLE_SPI_RXCNT, remaining_rx);  in apple_spi_transfer_one()
400 	apple_spi_tx(spi, &tx_ptr, &remaining_tx, bytes_per_word);  in apple_spi_transfer_one()
403 	reg_write(spi, APPLE_SPI_CTRL, APPLE_SPI_CTRL_RUN);  in apple_spi_transfer_one()
406 	apple_spi_tx(spi, &tx_ptr, &remaining_tx, bytes_per_word);  in apple_spi_transfer_one()
417 		ret = apple_spi_wait(spi, fifo_flags, xfer_flags, poll);  in apple_spi_transfer_one()
425 		xfer_flags &= ~reg_read(spi, APPLE_SPI_IF_XFER);  in apple_spi_transfer_one()
428 		apple_spi_tx(spi, &tx_ptr, &remaining_tx, bytes_per_word);  in apple_spi_transfer_one()
429 		apple_spi_rx(spi, &rx_ptr, &remaining_rx, bytes_per_word);  in apple_spi_transfer_one()
437 		apple_spi_rx(spi, &rx_ptr, &remaining_rx, bytes_per_word);  in apple_spi_transfer_one()
447 	fifo_flags = reg_read(spi, APPLE_SPI_IF_FIFO);  in apple_spi_transfer_one()
452 	reg_write(spi, APPLE_SPI_CTRL, 0);  in apple_spi_transfer_one()
459 	struct apple_spi *spi;  in apple_spi_probe()  local
467 	spi = spi_controller_get_devdata(ctlr);  in apple_spi_probe()
468 	init_completion(&spi->done);  in apple_spi_probe()
470 	spi->regs = devm_platform_ioremap_resource(pdev, 0);  in apple_spi_probe()
471 	if (IS_ERR(spi->regs))  in apple_spi_probe()
472 		return PTR_ERR(spi->regs);  in apple_spi_probe()
474 	spi->clk = devm_clk_get_enabled(&pdev->dev, NULL);  in apple_spi_probe()
475 	if (IS_ERR(spi->clk))  in apple_spi_probe()
476 		return dev_err_probe(&pdev->dev, PTR_ERR(spi->clk),  in apple_spi_probe()
484 			       dev_name(&pdev->dev), spi);  in apple_spi_probe()
504 	apple_spi_init(spi);  in apple_spi_probe()
514 	{ .compatible = "apple,spi", },
522 		.name = "apple-spi",
529 MODULE_DESCRIPTION("Apple SoC SPI driver");