4 * Copyright (C) 2011 Renesas Solutions Corp.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
27 static void sh_spi_write(unsigned long data, unsigned long *reg)
32 static unsigned long sh_spi_read(unsigned long *reg)
37 static void sh_spi_set_bit(unsigned long val, unsigned long *reg)
41 tmp = sh_spi_read(reg);
43 sh_spi_write(tmp, reg);
46 static void sh_spi_clear_bit(unsigned long val, unsigned long *reg)
50 tmp = sh_spi_read(reg);
52 sh_spi_write(tmp, reg);
55 static void clear_fifo(struct sh_spi *ss)
57 sh_spi_set_bit(SH_SPI_RSTF, &ss->regs->cr2);
58 sh_spi_clear_bit(SH_SPI_RSTF, &ss->regs->cr2);
61 static int recvbuf_wait(struct sh_spi *ss)
63 while (sh_spi_read(&ss->regs->cr1) & SH_SPI_RBE) {
71 static int write_fifo_empty_wait(struct sh_spi *ss)
73 while (!(sh_spi_read(&ss->regs->cr1) & SH_SPI_TBE)) {
85 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
86 unsigned int max_hz, unsigned int mode)
90 if (!spi_cs_is_valid(bus, cs))
93 ss = malloc(sizeof(struct spi_slave));
99 ss->regs = (struct sh_spi_regs *)CONFIG_SH_SPI_BASE;
102 sh_spi_write(0xfe, &ss->regs->cr1);
104 sh_spi_write(0x00, &ss->regs->cr1);
106 sh_spi_write(0x00, &ss->regs->cr3);
111 sh_spi_write(sh_spi_read(&ss->regs->cr2) | 0x07, &ss->regs->cr2);
117 void spi_free_slave(struct spi_slave *slave)
119 struct sh_spi *spi = to_sh_spi(slave);
124 int spi_claim_bus(struct spi_slave *slave)
129 void spi_release_bus(struct spi_slave *slave)
131 struct sh_spi *ss = to_sh_spi(slave);
133 sh_spi_write(sh_spi_read(&ss->regs->cr1) &
134 ~(SH_SPI_SSA | SH_SPI_SSDB | SH_SPI_SSD), &ss->regs->cr1);
137 static int sh_spi_send(struct sh_spi *ss, const unsigned char *tx_data,
138 unsigned int len, unsigned long flags)
140 int i, cur_len, ret = 0;
141 int remain = (int)len;
144 if (len >= SH_SPI_FIFO_SIZE)
145 sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
148 cur_len = (remain < SH_SPI_FIFO_SIZE) ?
149 remain : SH_SPI_FIFO_SIZE;
150 for (i = 0; i < cur_len &&
151 !(sh_spi_read(&ss->regs->cr4) & SH_SPI_WPABRT) &&
152 !(sh_spi_read(&ss->regs->cr1) & SH_SPI_TBF);
154 sh_spi_write(tx_data[i], &ss->regs->tbr_rbr);
158 if (sh_spi_read(&ss->regs->cr4) & SH_SPI_WPABRT) {
159 /* Abort the transaction */
160 flags |= SPI_XFER_END;
161 sh_spi_set_bit(SH_SPI_WPABRT, &ss->regs->cr4);
170 write_fifo_empty_wait(ss);
173 if (flags & SPI_XFER_END) {
174 tmp = sh_spi_read(&ss->regs->cr1);
175 tmp = tmp & ~(SH_SPI_SSD | SH_SPI_SSDB);
176 sh_spi_write(tmp, &ss->regs->cr1);
177 sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
179 write_fifo_empty_wait(ss);
185 static int sh_spi_receive(struct sh_spi *ss, unsigned char *rx_data,
186 unsigned int len, unsigned long flags)
191 if (len > SH_SPI_MAX_BYTE)
192 sh_spi_write(SH_SPI_MAX_BYTE, &ss->regs->cr3);
194 sh_spi_write(len, &ss->regs->cr3);
196 tmp = sh_spi_read(&ss->regs->cr1);
197 tmp = tmp & ~(SH_SPI_SSD | SH_SPI_SSDB);
198 sh_spi_write(tmp, &ss->regs->cr1);
199 sh_spi_set_bit(SH_SPI_SSA, &ss->regs->cr1);
201 for (i = 0; i < len; i++) {
202 if (recvbuf_wait(ss))
205 rx_data[i] = (unsigned char)sh_spi_read(&ss->regs->tbr_rbr);
207 sh_spi_write(0, &ss->regs->cr3);
212 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
213 void *din, unsigned long flags)
215 struct sh_spi *ss = to_sh_spi(slave);
216 const unsigned char *tx_data = dout;
217 unsigned char *rx_data = din;
218 unsigned int len = bitlen / 8;
221 if (flags & SPI_XFER_BEGIN)
222 sh_spi_write(sh_spi_read(&ss->regs->cr1) & ~SH_SPI_SSA,
226 ret = sh_spi_send(ss, tx_data, len, flags);
228 if (ret == 0 && rx_data)
229 ret = sh_spi_receive(ss, rx_data, len, flags);
231 if (flags & SPI_XFER_END) {
232 sh_spi_set_bit(SH_SPI_SSD, &ss->regs->cr1);
235 sh_spi_clear_bit(SH_SPI_SSA | SH_SPI_SSDB | SH_SPI_SSD,
243 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
245 /* This driver supports "bus = 0" and "cs = 0" only. */
252 void spi_cs_activate(struct spi_slave *slave)
257 void spi_cs_deactivate(struct spi_slave *slave)