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/kirkwood.h>
  16 #include <asm/arch/spi.h>
  17 #include <asm/arch/mpp.h>
  18
  19 static struct kwspi_registers *spireg = (struct kwspi_registers *)KW_SPI_BASE;
  20
  21 u32 cs_spi_mpp_back[2];
  22
  23 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  24                                 unsigned int max_hz, unsigned int mode)
  25 {
  26         struct spi_slave *slave;
  27         u32 data;
  28         static const u32 kwspi_mpp_config[2][2] = {
  29                 { MPP0_SPI_SCn, 0 }, /* if cs == 0 */
  30                 { MPP7_SPI_SCn, 0 } /* if cs != 0 */
  31         };
  32
  33         if (!spi_cs_is_valid(bus, cs))
  34                 return NULL;
  35
  36         slave = spi_alloc_slave_base(bus, cs);
  37         if (!slave)
  38                 return NULL;
  39
  40         writel(~KWSPI_CSN_ACT | KWSPI_SMEMRDY, &spireg->ctrl);
  41
  42         /* calculate spi clock prescaller using max_hz */
  43         data = ((CONFIG_SYS_TCLK / 2) / max_hz) + 0x10;
  44         data = data < KWSPI_CLKPRESCL_MIN ? KWSPI_CLKPRESCL_MIN : data;
  45         data = data > KWSPI_CLKPRESCL_MASK ? KWSPI_CLKPRESCL_MASK : data;
  46
  47         /* program spi clock prescaller using max_hz */
  48         writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg);
  49         debug("data = 0x%08x \n", data);
  50
  51         writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause);
  52         writel(KWSPI_IRQMASK, &spireg->irq_mask);
  53
  54         /* program mpp registers to select  SPI_CSn */
  55         kirkwood_mpp_conf(kwspi_mpp_config[cs ? 1 : 0], cs_spi_mpp_back);
  56
  57         return slave;
  58 }
  59
  60 void spi_free_slave(struct spi_slave *slave)
  61 {
  62         kirkwood_mpp_conf(cs_spi_mpp_back, NULL);
  63         free(slave);
  64 }
  65
  66 #if defined(CONFIG_SYS_KW_SPI_MPP)
  67 u32 spi_mpp_backup[4];
  68 #endif
  69
  70 __attribute__((weak)) int board_spi_claim_bus(struct spi_slave *slave)
  71 {
  72         return 0;
  73 }
  74
  75 int spi_claim_bus(struct spi_slave *slave)
  76 {
  77 #if defined(CONFIG_SYS_KW_SPI_MPP)
  78         u32 config;
  79         u32 spi_mpp_config[4];
  80
  81         config = CONFIG_SYS_KW_SPI_MPP;
  82
  83         if (config & MOSI_MPP6)
  84                 spi_mpp_config[0] = MPP6_SPI_MOSI;
  85         else
  86                 spi_mpp_config[0] = MPP1_SPI_MOSI;
  87
  88         if (config & SCK_MPP10)
  89                 spi_mpp_config[1] = MPP10_SPI_SCK;
  90         else
  91                 spi_mpp_config[1] = MPP2_SPI_SCK;
  92
  93         if (config & MISO_MPP11)
  94                 spi_mpp_config[2] = MPP11_SPI_MISO;
  95         else
  96                 spi_mpp_config[2] = MPP3_SPI_MISO;
  97
  98         spi_mpp_config[3] = 0;
  99         spi_mpp_backup[3] = 0;
 100
 101         /* set new spi mpp and save current mpp config */
 102         kirkwood_mpp_conf(spi_mpp_config, spi_mpp_backup);
 103
 104 #endif
 105
 106         return board_spi_claim_bus(slave);
 107 }
 108
 109 __attribute__((weak)) void board_spi_release_bus(struct spi_slave *slave)
 110 {
 111 }
 112
 113 void spi_release_bus(struct spi_slave *slave)
 114 {
 115 #if defined(CONFIG_SYS_KW_SPI_MPP)
 116         kirkwood_mpp_conf(spi_mpp_backup, NULL);
 117 #endif
 118
 119         board_spi_release_bus(slave);
 120 }
 121
 122 #ifndef CONFIG_SPI_CS_IS_VALID
 123 /*
 124  * you can define this function board specific
 125  * define above CONFIG in board specific config file and
 126  * provide the function in board specific src file
 127  */
 128 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
 129 {
 130         return (bus == 0 && (cs == 0 || cs == 1));
 131 }
 132 #endif
 133
 134 void spi_init(void)
 135 {
 136 }
 137
 138 void spi_cs_activate(struct spi_slave *slave)
 139 {
 140         writel(readl(&spireg->ctrl) | KWSPI_IRQUNMASK, &spireg->ctrl);
 141 }
 142
 143 void spi_cs_deactivate(struct spi_slave *slave)
 144 {
 145         writel(readl(&spireg->ctrl) & KWSPI_IRQMASK, &spireg->ctrl);
 146 }
 147
 148 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
 149              void *din, unsigned long flags)
 150 {
 151         unsigned int tmpdout, tmpdin;
 152         int tm, isread = 0;
 153
 154         debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
 155               slave->bus, slave->cs, dout, din, bitlen);
 156
 157         if (flags & SPI_XFER_BEGIN)
 158                 spi_cs_activate(slave);
 159
 160         /*
 161          * handle data in 8-bit chunks
 162          * TBD: 2byte xfer mode to be enabled
 163          */
 164         writel(((readl(&spireg->cfg) & ~KWSPI_XFERLEN_MASK) |
 165                 KWSPI_XFERLEN_1BYTE), &spireg->cfg);
 166
 167         while (bitlen > 4) {
 168                 debug("loopstart bitlen %d\n", bitlen);
 169                 tmpdout = 0;
 170
 171                 /* Shift data so it's msb-justified */
 172                 if (dout)
 173                         tmpdout = *(u32 *) dout & 0x0ff;
 174
 175                 writel(~KWSPI_SMEMRDIRQ, &spireg->irq_cause);
 176                 writel(tmpdout, &spireg->dout); /* Write the data out */
 177                 debug("*** spi_xfer: ... %08x written, bitlen %d\n",
 178                       tmpdout, bitlen);
 179
 180                 /*
 181                  * Wait for SPI transmit to get out
 182                  * or time out (1 second = 1000 ms)
 183                  * The NE event must be read and cleared first
 184                  */
 185                 for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
 186                         if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
 187                                 isread = 1;
 188                                 tmpdin = readl(&spireg->din);
 189                                 debug
 190                                         ("spi_xfer: din %p..%08x read\n",
 191                                         din, tmpdin);
 192
 193                                 if (din) {
 194                                         *((u8 *) din) = (u8) tmpdin;
 195                                         din += 1;
 196                                 }
 197                                 if (dout)
 198                                         dout += 1;
 199                                 bitlen -= 8;
 200                         }
 201                         if (isread)
 202                                 break;
 203                 }
 204                 if (tm >= KWSPI_TIMEOUT)
 205                         printf("*** spi_xfer: Time out during SPI transfer\n");
 206
 207                 debug("loopend bitlen %d\n", bitlen);
 208         }
 209
 210         if (flags & SPI_XFER_END)
 211                 spi_cs_deactivate(slave);
 212
 213         return 0;
 214 }