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         static const u32 kwspi_mpp_config[2][2] = {
  45                 { MPP0_SPI_SCn, 0 }, /* if cs == 0 */
  46                 { MPP7_SPI_SCn, 0 } /* if cs != 0 */
  47         };
  48
  49         if (!spi_cs_is_valid(bus, cs))
  50                 return NULL;
  51
  52         slave = spi_alloc_slave_base(bus, cs);
  53         if (!slave)
  54                 return NULL;
  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         kirkwood_mpp_conf(kwspi_mpp_config[cs ? 1 : 0], cs_spi_mpp_back);
  72
  73         return slave;
  74 }
  75
  76 void spi_free_slave(struct spi_slave *slave)
  77 {
  78         kirkwood_mpp_conf(cs_spi_mpp_back, NULL);
  79         free(slave);
  80 }
  81
  82 #if defined(CONFIG_SYS_KW_SPI_MPP)
  83 u32 spi_mpp_backup[4];
  84 #endif
  85
  86 __attribute__((weak)) int board_spi_claim_bus(struct spi_slave *slave)
  87 {
  88         return 0;
  89 }
  90
  91 int spi_claim_bus(struct spi_slave *slave)
  92 {
  93 #if defined(CONFIG_SYS_KW_SPI_MPP)
  94         u32 config;
  95         u32 spi_mpp_config[4];
  96
  97         config = CONFIG_SYS_KW_SPI_MPP;
  98
  99         if (config & MOSI_MPP6)
 100                 spi_mpp_config[0] = MPP6_SPI_MOSI;
 101         else
 102                 spi_mpp_config[0] = MPP1_SPI_MOSI;
 103
 104         if (config & SCK_MPP10)
 105                 spi_mpp_config[1] = MPP10_SPI_SCK;
 106         else
 107                 spi_mpp_config[1] = MPP2_SPI_SCK;
 108
 109         if (config & MISO_MPP11)
 110                 spi_mpp_config[2] = MPP11_SPI_MISO;
 111         else
 112                 spi_mpp_config[2] = MPP3_SPI_MISO;
 113
 114         spi_mpp_config[3] = 0;
 115         spi_mpp_backup[3] = 0;
 116
 117         /* set new spi mpp and save current mpp config */
 118         kirkwood_mpp_conf(spi_mpp_config, spi_mpp_backup);
 119
 120 #endif
 121
 122         return board_spi_claim_bus(slave);
 123 }
 124
 125 __attribute__((weak)) void board_spi_release_bus(struct spi_slave *slave)
 126 {
 127 }
 128
 129 void spi_release_bus(struct spi_slave *slave)
 130 {
 131 #if defined(CONFIG_SYS_KW_SPI_MPP)
 132         kirkwood_mpp_conf(spi_mpp_backup, NULL);
 133 #endif
 134
 135         board_spi_release_bus(slave);
 136 }
 137
 138 #ifndef CONFIG_SPI_CS_IS_VALID
 139 /*
 140  * you can define this function board specific
 141  * define above CONFIG in board specific config file and
 142  * provide the function in board specific src file
 143  */
 144 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 145 {
 146         return (bus == 0 && (cs == 0 || cs == 1));
 147 }
 148 #endif
 149
 150 void spi_init(void)
 151 {
 152 }
 153
 154 void spi_cs_activate(struct spi_slave *slave)
 155 {
 156         writel(readl(&spireg->ctrl) | KWSPI_IRQUNMASK, &spireg->ctrl);
 157 }
 158
 159 void spi_cs_deactivate(struct spi_slave *slave)
 160 {
 161         writel(readl(&spireg->ctrl) & KWSPI_IRQMASK, &spireg->ctrl);
 162 }
 163
 164 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 165              void *din, unsigned long flags)
 166 {
 167         unsigned int tmpdout, tmpdin;
 168         int tm, isread = 0;
 169
 170         debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
 171               slave->bus, slave->cs, dout, din, bitlen);
 172
 173         if (flags & SPI_XFER_BEGIN)
 174                 spi_cs_activate(slave);
 175
 176         /*
 177          * handle data in 8-bit chunks
 178          * TBD: 2byte xfer mode to be enabled
 179          */
 180         writel(((readl(&spireg->cfg) & ~KWSPI_XFERLEN_MASK) |
 181                 KWSPI_XFERLEN_1BYTE), &spireg->cfg);
 182
 183         while (bitlen > 4) {
 184                 debug("loopstart bitlen %d\n", bitlen);
 185                 tmpdout = 0;
 186
 187                 /* Shift data so it's msb-justified */
 188                 if (dout)
 189                         tmpdout = *(u32 *) dout & 0x0ff;
 190
 191                 writel(~KWSPI_SMEMRDIRQ, &spireg->irq_cause);
 192                 writel(tmpdout, &spireg->dout); /* Write the data out */
 193                 debug("*** spi_xfer: ... %08x written, bitlen %d\n",
 194                       tmpdout, bitlen);
 195
 196                 /*
 197                  * Wait for SPI transmit to get out
 198                  * or time out (1 second = 1000 ms)
 199                  * The NE event must be read and cleared first
 200                  */
 201                 for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
 202                         if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
 203                                 isread = 1;
 204                                 tmpdin = readl(&spireg->din);
 205                                 debug
 206                                         ("spi_xfer: din %p..%08x read\n",
 207                                         din, tmpdin);
 208
 209                                 if (din) {
 210                                         *((u8 *) din) = (u8) tmpdin;
 211                                         din += 1;
 212                                 }
 213                                 if (dout)
 214                                         dout += 1;
 215                                 bitlen -= 8;
 216                         }
 217                         if (isread)
 218                                 break;
 219                 }
 220                 if (tm >= KWSPI_TIMEOUT)
 221                         printf("*** spi_xfer: Time out during SPI transfer\n");
 222
 223                 debug("loopend bitlen %d\n", bitlen);
 224         }
 225
 226         if (flags & SPI_XFER_END)
 227                 spi_cs_deactivate(slave);
 228
 229         return 0;
 230 }