diff options
Diffstat (limited to 'arch/ppc/cpu/mpc8260/spi.c')
| -rw-r--r-- | arch/ppc/cpu/mpc8260/spi.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/arch/ppc/cpu/mpc8260/spi.c b/arch/ppc/cpu/mpc8260/spi.c new file mode 100644 index 0000000..f5d2ac3 --- /dev/null +++ b/arch/ppc/cpu/mpc8260/spi.c @@ -0,0 +1,435 @@ +/* + * Copyright (c) 2001 Navin Boppuri / Prashant Patel + * <nboppuri@trinetcommunication.com>, + * <pmpatel@trinetcommunication.com> + * Copyright (c) 2001 Gerd Mennchen <Gerd.Mennchen@icn.siemens.de> + * Copyright (c) 2001-2003 Wolfgang Denk, DENX Software Engineering, <wd@denx.de>. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +/* + * MPC8260 CPM SPI interface. + * + * Parts of this code are probably not portable and/or specific to + * the board which I used for the tests. Please send fixes/complaints + * to wd@denx.de + * + */ + +#include <common.h> +#include <asm/cpm_8260.h> +#include <linux/ctype.h> +#include <malloc.h> +#include <post.h> +#include <net.h> + +#if defined(CONFIG_SPI) + +/* Warning: + * You cannot enable DEBUG for early system initalization, i. e. when + * this driver is used to read environment parameters like "baudrate" + * from EEPROM which are used to initialize the serial port which is + * needed to print the debug messages... + */ +#undef DEBUG + +#define SPI_EEPROM_WREN 0x06 +#define SPI_EEPROM_RDSR 0x05 +#define SPI_EEPROM_READ 0x03 +#define SPI_EEPROM_WRITE 0x02 + +/* --------------------------------------------------------------- + * Offset for initial SPI buffers in DPRAM: + * We need a 520 byte scratch DPRAM area to use at an early stage. + * It is used between the two initialization calls (spi_init_f() + * and spi_init_r()). + * The value 0x2000 makes it far enough from the start of the data + * area (as well as from the stack pointer). + * --------------------------------------------------------------- */ +#ifndef CONFIG_SYS_SPI_INIT_OFFSET +#define CONFIG_SYS_SPI_INIT_OFFSET 0x2000 +#endif + +#define CPM_SPI_BASE 0x100 + +#ifdef DEBUG + +#define DPRINT(a) printf a; +/* ----------------------------------------------- + * Helper functions to peek into tx and rx buffers + * ----------------------------------------------- */ +static const char * const hex_digit = "0123456789ABCDEF"; + +static char quickhex (int i) +{ + return hex_digit[i]; +} + +static void memdump (void *pv, int num) +{ + int i; + unsigned char *pc = (unsigned char *) pv; + + for (i = 0; i < num; i++) + printf ("%c%c ", quickhex (pc[i] >> 4), quickhex (pc[i] & 0x0f)); + printf ("\t"); + for (i = 0; i < num; i++) + printf ("%c", isprint (pc[i]) ? pc[i] : '.'); + printf ("\n"); +} +#else /* !DEBUG */ + +#define DPRINT(a) + +#endif /* DEBUG */ + +/* ------------------- + * Function prototypes + * ------------------- */ +void spi_init (void); + +ssize_t spi_read (uchar *, int, uchar *, int); +ssize_t spi_write (uchar *, int, uchar *, int); +ssize_t spi_xfer (size_t); + +/* ------------------- + * Variables + * ------------------- */ + +#define MAX_BUFFER 0x104 + +/* ---------------------------------------------------------------------- + * Initially we place the RX and TX buffers at a fixed location in DPRAM! + * ---------------------------------------------------------------------- */ +static uchar *rxbuf = + (uchar *)&((immap_t *)CONFIG_SYS_IMMR)->im_dprambase + [CONFIG_SYS_SPI_INIT_OFFSET]; +static uchar *txbuf = + (uchar *)&((immap_t *)CONFIG_SYS_IMMR)->im_dprambase + [CONFIG_SYS_SPI_INIT_OFFSET+MAX_BUFFER]; + +/* ************************************************************************** + * + * Function: spi_init_f + * + * Description: Init SPI-Controller (ROM part) + * + * return: --- + * + * *********************************************************************** */ +void spi_init_f (void) +{ + unsigned int dpaddr; + + volatile spi_t *spi; + volatile immap_t *immr; + volatile cpm8260_t *cp; + volatile cbd_t *tbdf, *rbdf; + + immr = (immap_t *) CONFIG_SYS_IMMR; + cp = (cpm8260_t *) &immr->im_cpm; + + *(ushort *)(&immr->im_dprambase[PROFF_SPI_BASE]) = PROFF_SPI; + spi = (spi_t *)&immr->im_dprambase[PROFF_SPI]; + +/* 1 */ + /* ------------------------------------------------ + * Initialize Port D SPI pins + * (we are only in Master Mode !) + * ------------------------------------------------ */ + + /* -------------------------------------------- + * GPIO or per. Function + * PPARD[16] = 1 [0x00008000] (SPIMISO) + * PPARD[17] = 1 [0x00004000] (SPIMOSI) + * PPARD[18] = 1 [0x00002000] (SPICLK) + * PPARD[12] = 0 [0x00080000] -> GPIO: (CS for ATC EEPROM) + * -------------------------------------------- */ + immr->im_ioport.iop_ppard |= 0x0000E000; /* set bits */ + immr->im_ioport.iop_ppard &= ~0x00080000; /* reset bit */ + + /* ---------------------------------------------- + * In/Out or per. Function 0/1 + * PDIRD[16] = 0 [0x00008000] -> PERI1: SPIMISO + * PDIRD[17] = 0 [0x00004000] -> PERI1: SPIMOSI + * PDIRD[18] = 0 [0x00002000] -> PERI1: SPICLK + * PDIRD[12] = 1 [0x00080000] -> GPIO OUT: CS for ATC EEPROM + * ---------------------------------------------- */ + immr->im_ioport.iop_pdird &= ~0x0000E000; + immr->im_ioport.iop_pdird |= 0x00080000; + + /* ---------------------------------------------- + * special option reg. + * PSORD[16] = 1 [0x00008000] -> SPIMISO + * PSORD[17] = 1 [0x00004000] -> SPIMOSI + * PSORD[18] = 1 [0x00002000] -> SPICLK + * ---------------------------------------------- */ + immr->im_ioport.iop_psord |= 0x0000E000; + + /* Initialize the parameter ram. + * We need to make sure many things are initialized to zero + */ + spi->spi_rstate = 0; + spi->spi_rdp = 0; + spi->spi_rbptr = 0; + spi->spi_rbc = 0; + spi->spi_rxtmp = 0; + spi->spi_tstate = 0; + spi->spi_tdp = 0; + spi->spi_tbptr = 0; + spi->spi_tbc = 0; + spi->spi_txtmp = 0; + + /* Allocate space for one transmit and one receive buffer + * descriptor in the DP ram + */ +#ifdef CONFIG_SYS_ALLOC_DPRAM + dpaddr = m8260_cpm_dpalloc (sizeof(cbd_t)*2, 8); +#else + dpaddr = CPM_SPI_BASE; +#endif + +/* 3 */ + /* Set up the SPI parameters in the parameter ram */ + spi->spi_rbase = dpaddr; + spi->spi_tbase = dpaddr + sizeof (cbd_t); + + /***********IMPORTANT******************/ + + /* + * Setting transmit and receive buffer descriptor pointers + * initially to rbase and tbase. Only the microcode patches + * documentation talks about initializing this pointer. This + * is missing from the sample I2C driver. If you dont + * initialize these pointers, the kernel hangs. + */ + spi->spi_rbptr = spi->spi_rbase; + spi->spi_tbptr = spi->spi_tbase; + +/* 4 */ + /* Init SPI Tx + Rx Parameters */ + while (cp->cp_cpcr & CPM_CR_FLG) + ; + cp->cp_cpcr = mk_cr_cmd(CPM_CR_SPI_PAGE, CPM_CR_SPI_SBLOCK, + 0, CPM_CR_INIT_TRX) | CPM_CR_FLG; + while (cp->cp_cpcr & CPM_CR_FLG) + ; + +/* 6 */ + /* Set to big endian. */ + spi->spi_tfcr = CPMFCR_EB; + spi->spi_rfcr = CPMFCR_EB; + +/* 7 */ + /* Set maximum receive size. */ + spi->spi_mrblr = MAX_BUFFER; + +/* 8 + 9 */ + /* tx and rx buffer descriptors */ + tbdf = (cbd_t *) & immr->im_dprambase[spi->spi_tbase]; + rbdf = (cbd_t *) & immr->im_dprambase[spi->spi_rbase]; + + tbdf->cbd_sc &= ~BD_SC_READY; + rbdf->cbd_sc &= ~BD_SC_EMPTY; + + /* Set the bd's rx and tx buffer address pointers */ + rbdf->cbd_bufaddr = (ulong) rxbuf; + tbdf->cbd_bufaddr = (ulong) txbuf; + +/* 10 + 11 */ + immr->im_spi.spi_spie = SPI_EMASK; /* Clear all SPI events */ + immr->im_spi.spi_spim = 0x00; /* Mask all SPI events */ + + + return; +} + +/* ************************************************************************** + * + * Function: spi_init_r + * + * Description: Init SPI-Controller (RAM part) - + * The malloc engine is ready and we can move our buffers to + * normal RAM + * + * return: --- + * + * *********************************************************************** */ +void spi_init_r (void) +{ + volatile spi_t *spi; + volatile immap_t *immr; + volatile cpm8260_t *cp; + volatile cbd_t *tbdf, *rbdf; + + immr = (immap_t *) CONFIG_SYS_IMMR; + cp = (cpm8260_t *) &immr->im_cpm; + + spi = (spi_t *)&immr->im_dprambase[PROFF_SPI]; + + /* tx and rx buffer descriptors */ + tbdf = (cbd_t *) & immr->im_dprambase[spi->spi_tbase]; + rbdf = (cbd_t *) & immr->im_dprambase[spi->spi_rbase]; + + /* Allocate memory for RX and TX buffers */ + rxbuf = (uchar *) malloc (MAX_BUFFER); + txbuf = (uchar *) malloc (MAX_BUFFER); + + rbdf->cbd_bufaddr = (ulong) rxbuf; + tbdf->cbd_bufaddr = (ulong) txbuf; + + return; +} + +/**************************************************************************** + * Function: spi_write + **************************************************************************** */ +ssize_t spi_write (uchar *addr, int alen, uchar *buffer, int len) +{ + int i; + + memset(rxbuf, 0, MAX_BUFFER); + memset(txbuf, 0, MAX_BUFFER); + *txbuf = SPI_EEPROM_WREN; /* write enable */ + spi_xfer(1); + memcpy(txbuf, addr, alen); + *txbuf = SPI_EEPROM_WRITE; /* WRITE memory array */ + memcpy(alen + txbuf, buffer, len); + spi_xfer(alen + len); + /* ignore received data */ + for (i = 0; i < 1000; i++) { + *txbuf = SPI_EEPROM_RDSR; /* read status */ + txbuf[1] = 0; + spi_xfer(2); + if (!(rxbuf[1] & 1)) { + break; + } + udelay(1000); + } + if (i >= 1000) { + printf ("*** spi_write: Time out while writing!\n"); + } + + return len; +} + +/**************************************************************************** + * Function: spi_read + **************************************************************************** */ +ssize_t spi_read (uchar *addr, int alen, uchar *buffer, int len) +{ + memset(rxbuf, 0, MAX_BUFFER); + memset(txbuf, 0, MAX_BUFFER); + memcpy(txbuf, addr, alen); + *txbuf = SPI_EEPROM_READ; /* READ memory array */ + + /* + * There is a bug in 860T (?) that cuts the last byte of input + * if we're reading into DPRAM. The solution we choose here is + * to always read len+1 bytes (we have one extra byte at the + * end of the buffer). + */ + spi_xfer(alen + len + 1); + memcpy(buffer, alen + rxbuf, len); + + return len; +} + +/**************************************************************************** + * Function: spi_xfer + **************************************************************************** */ +ssize_t spi_xfer (size_t count) +{ + volatile immap_t *immr; + volatile cpm8260_t *cp; + volatile spi_t *spi; + cbd_t *tbdf, *rbdf; + int tm; + + DPRINT (("*** spi_xfer entered ***\n")); + + immr = (immap_t *) CONFIG_SYS_IMMR; + cp = (cpm8260_t *) &immr->im_cpm; + + spi = (spi_t *)&immr->im_dprambase[PROFF_SPI]; + + tbdf = (cbd_t *) & immr->im_dprambase[spi->spi_tbase]; + rbdf = (cbd_t *) & immr->im_dprambase[spi->spi_rbase]; + + /* Board-specific: Set CS for device (ATC EEPROM) */ + immr->im_ioport.iop_pdatd &= ~0x00080000; + + /* Setting tx bd status and data length */ + tbdf->cbd_sc = BD_SC_READY | BD_SC_LAST | BD_SC_WRAP; + tbdf->cbd_datlen = count; + + DPRINT (("*** spi_xfer: Bytes to be xferred: %d ***\n", + tbdf->cbd_datlen)); + + /* Setting rx bd status and data length */ + rbdf->cbd_sc = BD_SC_EMPTY | BD_SC_WRAP; + rbdf->cbd_datlen = 0; /* rx length has no significance */ + + immr->im_spi.spi_spmode = SPMODE_REV | + SPMODE_MSTR | + SPMODE_EN | + SPMODE_LEN(8) | /* 8 Bits per char */ + SPMODE_PM(0x8) ; /* medium speed */ + immr->im_spi.spi_spie = SPI_EMASK; /* Clear all SPI events */ + immr->im_spi.spi_spim = 0x00; /* Mask all SPI events */ + + /* start spi transfer */ + DPRINT (("*** spi_xfer: Performing transfer ...\n")); + immr->im_spi.spi_spcom |= SPI_STR; /* Start transmit */ + + /* -------------------------------- + * Wait for SPI transmit to get out + * or time out (1 second = 1000 ms) + * -------------------------------- */ + for (tm=0; tm<1000; ++tm) { + if (immr->im_spi.spi_spie & SPI_TXB) { /* Tx Buffer Empty */ + DPRINT (("*** spi_xfer: Tx buffer empty\n")); + break; + } + if ((tbdf->cbd_sc & BD_SC_READY) == 0) { + DPRINT (("*** spi_xfer: Tx BD done\n")); + break; + } + udelay (1000); + } + if (tm >= 1000) { + printf ("*** spi_xfer: Time out while xferring to/from SPI!\n"); + } + DPRINT (("*** spi_xfer: ... transfer ended\n")); + +#ifdef DEBUG + printf ("\nspi_xfer: txbuf after xfer\n"); + memdump ((void *) txbuf, 16); /* dump of txbuf before transmit */ + printf ("spi_xfer: rxbuf after xfer\n"); + memdump ((void *) rxbuf, 16); /* dump of rxbuf after transmit */ + printf ("\n"); +#endif + + /* Clear CS for device */ + immr->im_ioport.iop_pdatd |= 0x00080000; + + return count; +} +#endif /* CONFIG_SPI */ |