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  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <common.h>
  12 #include <malloc.h>
  13 #include <spi.h>
  14 #include <asm/io.h>
  15 #include <asm/arch/soc.h>
  16 #ifdef CONFIG_KIRKWOOD
  17 #include <asm/arch/mpp.h>
  18 #endif
  19 #include <asm/arch-mvebu/spi.h>
  20
  21 static struct kwspi_registers *spireg =
  22         (struct kwspi_registers *)MVEBU_SPI_BASE;
  23
  24 #ifdef CONFIG_KIRKWOOD
  25 static u32 cs_spi_mpp_back[2];
  26 #endif
  27
  28 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  29                                 unsigned int max_hz, unsigned int mode)
  30 {
  31         struct spi_slave *slave;
  32         u32 data;
  33 #ifdef CONFIG_KIRKWOOD
  34         static const u32 kwspi_mpp_config[2][2] = {
  35                 { MPP0_SPI_SCn, 0 }, /* if cs == 0 */
  36                 { MPP7_SPI_SCn, 0 } /* if cs != 0 */
  37         };
  38 #endif
  39
  40         if (!spi_cs_is_valid(bus, cs))
  41                 return NULL;
  42
  43         slave = spi_alloc_slave_base(bus, cs);
  44         if (!slave)
  45                 return NULL;
  46
  47         writel(KWSPI_SMEMRDY, &spireg->ctrl);
  48
  49         /* calculate spi clock prescaller using max_hz */
  50         data = ((CONFIG_SYS_TCLK / 2) / max_hz) + 0x10;
  51         data = data < KWSPI_CLKPRESCL_MIN ? KWSPI_CLKPRESCL_MIN : data;
  52         data = data > KWSPI_CLKPRESCL_MASK ? KWSPI_CLKPRESCL_MASK : data;
  53
  54         /* program spi clock prescaller using max_hz */
  55         writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg);
  56         debug("data = 0x%08x\n", data);
  57
  58         writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause);
  59         writel(KWSPI_IRQMASK, &spireg->irq_mask);
  60
  61 #ifdef CONFIG_KIRKWOOD
  62         /* program mpp registers to select  SPI_CSn */
  63         kirkwood_mpp_conf(kwspi_mpp_config[cs ? 1 : 0], cs_spi_mpp_back);
  64 #endif
  65
  66         return slave;
  67 }
  68
  69 void spi_free_slave(struct spi_slave *slave)
  70 {
  71 #ifdef CONFIG_KIRKWOOD
  72         kirkwood_mpp_conf(cs_spi_mpp_back, NULL);
  73 #endif
  74         free(slave);
  75 }
  76
  77 #if defined(CONFIG_SYS_KW_SPI_MPP)
  78 u32 spi_mpp_backup[4];
  79 #endif
  80
  81 __attribute__((weak)) int board_spi_claim_bus(struct spi_slave *slave)
  82 {
  83         return 0;
  84 }
  85
  86 int spi_claim_bus(struct spi_slave *slave)
  87 {
  88 #if defined(CONFIG_SYS_KW_SPI_MPP)
  89         u32 config;
  90         u32 spi_mpp_config[4];
  91
  92         config = CONFIG_SYS_KW_SPI_MPP;
  93
  94         if (config & MOSI_MPP6)
  95                 spi_mpp_config[0] = MPP6_SPI_MOSI;
  96         else
  97                 spi_mpp_config[0] = MPP1_SPI_MOSI;
  98
  99         if (config & SCK_MPP10)
 100                 spi_mpp_config[1] = MPP10_SPI_SCK;
 101         else
 102                 spi_mpp_config[1] = MPP2_SPI_SCK;
 103
 104         if (config & MISO_MPP11)
 105                 spi_mpp_config[2] = MPP11_SPI_MISO;
 106         else
 107                 spi_mpp_config[2] = MPP3_SPI_MISO;
 108
 109         spi_mpp_config[3] = 0;
 110         spi_mpp_backup[3] = 0;
 111
 112         /* set new spi mpp and save current mpp config */
 113         kirkwood_mpp_conf(spi_mpp_config, spi_mpp_backup);
 114 #endif
 115
 116         return board_spi_claim_bus(slave);
 117 }
 118
 119 __attribute__((weak)) void board_spi_release_bus(struct spi_slave *slave)
 120 {
 121 }
 122
 123 void spi_release_bus(struct spi_slave *slave)
 124 {
 125 #if defined(CONFIG_SYS_KW_SPI_MPP)
 126         kirkwood_mpp_conf(spi_mpp_backup, NULL);
 127 #endif
 128
 129         board_spi_release_bus(slave);
 130 }
 131
 132 #ifndef CONFIG_SPI_CS_IS_VALID
 133 /*
 134  * you can define this function board specific
 135  * define above CONFIG in board specific config file and
 136  * provide the function in board specific src file
 137  */
 138 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 139 {
 140         return bus == 0 && (cs == 0 || cs == 1);
 141 }
 142 #endif
 143
 144 void spi_init(void)
 145 {
 146 }
 147
 148 void spi_cs_activate(struct spi_slave *slave)
 149 {
 150         setbits_le32(&spireg->ctrl, KWSPI_CSN_ACT);
 151 }
 152
 153 void spi_cs_deactivate(struct spi_slave *slave)
 154 {
 155         clrbits_le32(&spireg->ctrl, KWSPI_CSN_ACT);
 156 }
 157
 158 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 159              void *din, unsigned long flags)
 160 {
 161         unsigned int tmpdout, tmpdin;
 162         int tm, isread = 0;
 163
 164         debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
 165               slave->bus, slave->cs, dout, din, bitlen);
 166
 167         if (flags & SPI_XFER_BEGIN)
 168                 spi_cs_activate(slave);
 169
 170         /*
 171          * handle data in 8-bit chunks
 172          * TBD: 2byte xfer mode to be enabled
 173          */
 174         clrsetbits_le32(&spireg->cfg, KWSPI_XFERLEN_MASK, KWSPI_XFERLEN_1BYTE);
 175
 176         while (bitlen > 4) {
 177                 debug("loopstart bitlen %d\n", bitlen);
 178                 tmpdout = 0;
 179
 180                 /* Shift data so it's msb-justified */
 181                 if (dout)
 182                         tmpdout = *(u32 *)dout & 0xff;
 183
 184                 clrbits_le32(&spireg->irq_cause, KWSPI_SMEMRDIRQ);
 185                 writel(tmpdout, &spireg->dout); /* Write the data out */
 186                 debug("*** spi_xfer: ... %08x written, bitlen %d\n",
 187                       tmpdout, bitlen);
 188
 189                 /*
 190                  * Wait for SPI transmit to get out
 191                  * or time out (1 second = 1000 ms)
 192                  * The NE event must be read and cleared first
 193                  */
 194                 for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
 195                         if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
 196                                 isread = 1;
 197                                 tmpdin = readl(&spireg->din);
 198                                 debug("spi_xfer: din %p..%08x read\n",
 199                                       din, tmpdin);
 200
 201                                 if (din) {
 202                                         *((u8 *)din) = (u8)tmpdin;
 203                                         din += 1;
 204                                 }
 205                                 if (dout)
 206                                         dout += 1;
 207                                 bitlen -= 8;
 208                         }
 209                         if (isread)
 210                                 break;
 211                 }
 212                 if (tm >= KWSPI_TIMEOUT)
 213                         printf("*** spi_xfer: Time out during SPI transfer\n");
 214
 215                 debug("loopend bitlen %d\n", bitlen);
 216         }
 217
 218         if (flags & SPI_XFER_END)
 219                 spi_cs_deactivate(slave);
 220
 221         return 0;
 222 }