drivers/spi/kirkwood_spi.c

   1 /*
   2  * (C) Copyright 2009
   3  * Marvell Semiconductor <www.marvell.com>
   4  * Written-by: Prafulla Wadaskar <prafulla@marvell.com>
   5  *
   6  * Derived from drivers/spi/mpc8xxx_spi.c
   7  *
   8  * See file CREDITS for list of people who contributed to this
   9  * project.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License as
  13  * published by the Free Software Foundation; either version 2 of
  14  * the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  24  * MA 02110-1301 USA
  25  */
  26
  27 #include <common.h>
  28 #include <malloc.h>
  29 #include <spi.h>
  30 #include <asm/io.h>
  31 #include <asm/arch/kirkwood.h>
  32 #include <asm/arch/spi.h>
  33 #include <asm/arch/mpp.h>
  34
  35 static struct kwspi_registers *spireg = (struct kwspi_registers *)KW_SPI_BASE;
  36
  37 u32 cs_spi_mpp_back[2];
  38
  39 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  40                                 unsigned int max_hz, unsigned int mode)
  41 {
  42         struct spi_slave *slave;
  43         u32 data;
  44         u32 kwspi_mpp_config[] = { 0, 0 };
  45
  46         if (!spi_cs_is_valid(bus, cs))
  47                 return NULL;
  48
  49         slave = malloc(sizeof(struct spi_slave));
  50         if (!slave)
  51                 return NULL;
  52
  53         slave->bus = bus;
  54         slave->cs = cs;
  55
  56         writel(~KWSPI_CSN_ACT | KWSPI_SMEMRDY, &spireg->ctrl);
  57
  58         /* calculate spi clock prescaller using max_hz */
  59         data = ((CONFIG_SYS_TCLK / 2) / max_hz) + 0x10;
  60         data = data < KWSPI_CLKPRESCL_MIN ? KWSPI_CLKPRESCL_MIN : data;
  61         data = data > KWSPI_CLKPRESCL_MASK ? KWSPI_CLKPRESCL_MASK : data;
  62
  63         /* program spi clock prescaller using max_hz */
  64         writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg);
  65         debug("data = 0x%08x \n", data);
  66
  67         writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause);
  68         writel(KWSPI_IRQMASK, &spireg->irq_mask);
  69
  70         /* program mpp registers to select  SPI_CSn */
  71         if (cs) {
  72                 kwspi_mpp_config[0] = MPP7_SPI_SCn;
  73         } else {
  74                 kwspi_mpp_config[0] = MPP0_SPI_SCn;
  75         }
  76         kirkwood_mpp_conf(kwspi_mpp_config, cs_spi_mpp_back);
  77
  78         return slave;
  79 }
  80
  81 void spi_free_slave(struct spi_slave *slave)
  82 {
  83         kirkwood_mpp_conf(cs_spi_mpp_back, NULL);
  84         free(slave);
  85 }
  86
  87 #if defined(CONFIG_SYS_KW_SPI_MPP)
  88 u32 spi_mpp_backup[4];
  89 #endif
  90
  91 __attribute__((weak)) int board_spi_claim_bus(struct spi_slave *slave)
  92 {
  93         return 0;
  94 }
  95
  96 int spi_claim_bus(struct spi_slave *slave)
  97 {
  98 #if defined(CONFIG_SYS_KW_SPI_MPP)
  99         u32 config;
 100         u32 spi_mpp_config[4];
 101
 102         config = CONFIG_SYS_KW_SPI_MPP;
 103
 104         if (config & MOSI_MPP6)
 105                 spi_mpp_config[0] = MPP6_SPI_MOSI;
 106         else
 107                 spi_mpp_config[0] = MPP1_SPI_MOSI;
 108
 109         if (config & SCK_MPP10)
 110                 spi_mpp_config[1] = MPP10_SPI_SCK;
 111         else
 112                 spi_mpp_config[1] = MPP2_SPI_SCK;
 113
 114         if (config & MISO_MPP11)
 115                 spi_mpp_config[2] = MPP11_SPI_MISO;
 116         else
 117                 spi_mpp_config[2] = MPP3_SPI_MISO;
 118
 119         spi_mpp_config[3] = 0;
 120         spi_mpp_backup[3] = 0;
 121
 122         /* set new spi mpp and save current mpp config */
 123         kirkwood_mpp_conf(spi_mpp_config, spi_mpp_backup);
 124
 125 #endif
 126
 127         return board_spi_claim_bus(slave);
 128 }
 129
 130 __attribute__((weak)) void board_spi_release_bus(struct spi_slave *slave)
 131 {
 132 }
 133
 134 void spi_release_bus(struct spi_slave *slave)
 135 {
 136 #if defined(CONFIG_SYS_KW_SPI_MPP)
 137         kirkwood_mpp_conf(spi_mpp_backup, NULL);
 138 #endif
 139
 140         board_spi_release_bus(slave);
 141 }
 142
 143 #ifndef CONFIG_SPI_CS_IS_VALID
 144 /*
 145  * you can define this function board specific
 146  * define above CONFIG in board specific config file and
 147  * provide the function in board specific src file
 148  */
 149 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 150 {
 151         return (bus == 0 && (cs == 0 || cs == 1));
 152 }
 153 #endif
 154
 155 void spi_init(void)
 156 {
 157 }
 158
 159 void spi_cs_activate(struct spi_slave *slave)
 160 {
 161         writel(readl(&spireg->ctrl) | KWSPI_IRQUNMASK, &spireg->ctrl);
 162 }
 163
 164 void spi_cs_deactivate(struct spi_slave *slave)
 165 {
 166         writel(readl(&spireg->ctrl) & KWSPI_IRQMASK, &spireg->ctrl);
 167 }
 168
 169 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 170              void *din, unsigned long flags)
 171 {
 172         unsigned int tmpdout, tmpdin;
 173         int tm, isread = 0;
 174
 175         debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
 176               slave->bus, slave->cs, dout, din, bitlen);
 177
 178         if (flags & SPI_XFER_BEGIN)
 179                 spi_cs_activate(slave);
 180
 181         /*
 182          * handle data in 8-bit chunks
 183          * TBD: 2byte xfer mode to be enabled
 184          */
 185         writel(((readl(&spireg->cfg) & ~KWSPI_XFERLEN_MASK) |
 186                 KWSPI_XFERLEN_1BYTE), &spireg->cfg);
 187
 188         while (bitlen > 4) {
 189                 debug("loopstart bitlen %d\n", bitlen);
 190                 tmpdout = 0;
 191
 192                 /* Shift data so it's msb-justified */
 193                 if (dout)
 194                         tmpdout = *(u32 *) dout & 0x0ff;
 195
 196                 writel(~KWSPI_SMEMRDIRQ, &spireg->irq_cause);
 197                 writel(tmpdout, &spireg->dout); /* Write the data out */
 198                 debug("*** spi_xfer: ... %08x written, bitlen %d\n",
 199                       tmpdout, bitlen);
 200
 201                 /*
 202                  * Wait for SPI transmit to get out
 203                  * or time out (1 second = 1000 ms)
 204                  * The NE event must be read and cleared first
 205                  */
 206                 for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
 207                         if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
 208                                 isread = 1;
 209                                 tmpdin = readl(&spireg->din);
 210                                 debug
 211                                         ("spi_xfer: din %p..%08x read\n",
 212                                         din, tmpdin);
 213
 214                                 if (din) {
 215                                         *((u8 *) din) = (u8) tmpdin;
 216                                         din += 1;
 217                                 }
 218                                 if (dout)
 219                                         dout += 1;
 220                                 bitlen -= 8;
 221                         }
 222                         if (isread)
 223                                 break;
 224                 }
 225                 if (tm >= KWSPI_TIMEOUT)
 226                         printf("*** spi_xfer: Time out during SPI transfer\n");
 227
 228                 debug("loopend bitlen %d\n", bitlen);
 229         }
 230
 231         if (flags & SPI_XFER_END)
 232                 spi_cs_deactivate(slave);
 233
 234         return 0;
 235 }