1 // SPDX-License-Identifier: GPL-2.0+
2 // Loongson SPI Support
5 #include <linux/clk.h>
15 #include <linux/spi/spi.h>
17 #include "spi-loongson.h"
19 static inline void loongson_spi_write_reg(struct loongson_spi *spi, unsigned char reg,  in loongson_spi_write_reg()  argument
22 	writeb(data, spi->base + reg);  in loongson_spi_write_reg()
25 static inline char loongson_spi_read_reg(struct loongson_spi *spi, unsigned char reg)  in loongson_spi_read_reg()  argument
27 	return readb(spi->base + reg);  in loongson_spi_read_reg()
30 static void loongson_spi_set_cs(struct spi_device *spi, bool en)  in loongson_spi_set_cs()  argument
33 	unsigned char mask = (BIT(4) | BIT(0)) << spi_get_chipselect(spi, 0);  in loongson_spi_set_cs()
34 	unsigned char val = en ? mask :  (BIT(0) << spi_get_chipselect(spi, 0));  in loongson_spi_set_cs()
35 	struct loongson_spi *loongson_spi = spi_controller_get_devdata(spi->controller);  in loongson_spi_set_cs()
47 	div = clamp_val(DIV_ROUND_UP_ULL(loongson_spi->clk_rate, hz), 2, 4096);  in loongson_spi_set_clk()
48 	div_tmp = rdiv[fls(div - 1)];  in loongson_spi_set_clk()
49 	loongson_spi->spcr = (div_tmp & GENMASK(1, 0)) >> 0;  in loongson_spi_set_clk()
50 	loongson_spi->sper = (div_tmp & GENMASK(3, 2)) >> 2;  in loongson_spi_set_clk()
54 			       loongson_spi->spcr);  in loongson_spi_set_clk()
58 			       loongson_spi->sper);  in loongson_spi_set_clk()
59 	loongson_spi->hz = hz;  in loongson_spi_set_clk()
63 				  struct spi_device *spi)  in loongson_spi_set_mode()  argument
69 	if (spi->mode & SPI_CPOL)  in loongson_spi_set_mode()
71 	if (spi->mode & SPI_CPHA)  in loongson_spi_set_mode()
75 	loongson_spi->mode |= spi->mode;  in loongson_spi_set_mode()
79 				struct spi_device *spi, struct spi_transfer *t)  in loongson_spi_update_state()  argument
81 	if (t && loongson_spi->hz != t->speed_hz)  in loongson_spi_update_state()
82 		loongson_spi_set_clk(loongson_spi, t->speed_hz);  in loongson_spi_update_state()
84 	if ((spi->mode ^ loongson_spi->mode) & SPI_MODE_X_MASK)  in loongson_spi_update_state()
85 		loongson_spi_set_mode(loongson_spi, spi);  in loongson_spi_update_state()
90 static int loongson_spi_setup(struct spi_device *spi)  in loongson_spi_setup()  argument
94 	loongson_spi = spi_controller_get_devdata(spi->controller);  in loongson_spi_setup()
95 	if (spi->bits_per_word % 8)  in loongson_spi_setup()
96 		return -EINVAL;  in loongson_spi_setup()
98 	if (spi_get_chipselect(spi, 0) >= spi->controller->num_chipselect)  in loongson_spi_setup()
99 		return -EINVAL;  in loongson_spi_setup()
101 	loongson_spi->hz = 0;  in loongson_spi_setup()
102 	loongson_spi_set_cs(spi, true);  in loongson_spi_setup()
107 static int loongson_spi_write_read_8bit(struct spi_device *spi, const u8 **tx_buf,  in loongson_spi_write_read_8bit()  argument
111 	struct loongson_spi *loongson_spi = spi_controller_get_devdata(spi->controller);  in loongson_spi_write_read_8bit()
118 	ret = readb_poll_timeout(loongson_spi->base + LOONGSON_SPI_SPSR_REG,  in loongson_spi_write_read_8bit()
119 				 loongson_spi->spsr, (loongson_spi->spsr &  in loongson_spi_write_read_8bit()
131 static int loongson_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)  in loongson_spi_write_read()  argument
135 	const u8 *tx = xfer->tx_buf;  in loongson_spi_write_read()
136 	u8 *rx = xfer->rx_buf;  in loongson_spi_write_read()
138 	count = xfer->len;  in loongson_spi_write_read()
140 		ret = loongson_spi_write_read_8bit(spi, &tx, &rx, count);  in loongson_spi_write_read()
143 	} while (--count);  in loongson_spi_write_read()
152 	loongson_spi->para = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_PARA_REG);  in loongson_spi_prepare_message()
153 	loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para &  in loongson_spi_prepare_message()
159 static int loongson_spi_transfer_one(struct spi_controller *ctrl, struct spi_device *spi,  in loongson_spi_transfer_one()  argument
162 	struct loongson_spi *loongson_spi = spi_controller_get_devdata(spi->controller);  in loongson_spi_transfer_one()
164 	loongson_spi_update_state(loongson_spi, spi, xfer);  in loongson_spi_transfer_one()
165 	if (xfer->len)  in loongson_spi_transfer_one()
166 		return loongson_spi_write_read(spi, xfer);  in loongson_spi_transfer_one()
175 	loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para);  in loongson_spi_unprepare_message()
199 	struct loongson_spi *spi;  in loongson_spi_init_controller()  local
200 	struct clk *clk;  in loongson_spi_init_controller()  local
204 		return -ENOMEM;  in loongson_spi_init_controller()
206 	controller->mode_bits = SPI_MODE_X_MASK | SPI_CS_HIGH;  in loongson_spi_init_controller()
207 	controller->setup = loongson_spi_setup;  in loongson_spi_init_controller()
208 	controller->prepare_message = loongson_spi_prepare_message;  in loongson_spi_init_controller()
209 	controller->transfer_one = loongson_spi_transfer_one;  in loongson_spi_init_controller()
210 	controller->unprepare_message = loongson_spi_unprepare_message;  in loongson_spi_init_controller()
211 	controller->set_cs = loongson_spi_set_cs;  in loongson_spi_init_controller()
212 	controller->num_chipselect = 4;  in loongson_spi_init_controller()
213 	device_set_node(&controller->dev, dev_fwnode(dev));  in loongson_spi_init_controller()
216 	spi = spi_controller_get_devdata(controller);  in loongson_spi_init_controller()
217 	spi->base = regs;  in loongson_spi_init_controller()
218 	spi->controller = controller;  in loongson_spi_init_controller()
220 	clk = devm_clk_get_optional(dev, NULL);  in loongson_spi_init_controller()
221 	if (IS_ERR(clk))  in loongson_spi_init_controller()
222 		return dev_err_probe(dev, PTR_ERR(clk), "unable to get clock\n");  in loongson_spi_init_controller()
224 	spi->clk_rate = clk_get_rate(clk);  in loongson_spi_init_controller()
225 	loongson_spi_reginit(spi);  in loongson_spi_init_controller()
227 	spi->mode = 0;  in loongson_spi_init_controller()
243 	loongson_spi->spcr = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPCR_REG);  in loongson_spi_suspend()
244 	loongson_spi->sper = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPER_REG);  in loongson_spi_suspend()
245 	loongson_spi->spsr = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SPSR_REG);  in loongson_spi_suspend()
246 	loongson_spi->para = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_PARA_REG);  in loongson_spi_suspend()
247 	loongson_spi->sfcs = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_SFCS_REG);  in loongson_spi_suspend()
248 	loongson_spi->timi = loongson_spi_read_reg(loongson_spi, LOONGSON_SPI_TIMI_REG);  in loongson_spi_suspend()
261 	loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPCR_REG, loongson_spi->spcr);  in loongson_spi_resume()
262 	loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPER_REG, loongson_spi->sper);  in loongson_spi_resume()
263 	loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SPSR_REG, loongson_spi->spsr);  in loongson_spi_resume()
264 	loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_PARA_REG, loongson_spi->para);  in loongson_spi_resume()
265 	loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_SFCS_REG, loongson_spi->sfcs);  in loongson_spi_resume()
266 	loongson_spi_write_reg(loongson_spi, LOONGSON_SPI_TIMI_REG, loongson_spi->timi);  in loongson_spi_resume()
279 MODULE_DESCRIPTION("Loongson SPI core driver");