andes_spi is an spi interface developed by Andes Tech.
Signed-off-by: Macpaul Lin macpaul@andestech.com Cc: Wolfgang Denk wd@denx.de Cc: Mike Frysinger vapier@gentoo.org --- Changes for v2: - Replace redundant length checking by min(len, 4). - Remove redundant debug marco. - Replace reading register in debug() by local variable. - Add Baud rate setup code (APB register) according to datasheet. Changes for v3: - Add comment to explain why the hardware doesn't allow changing frequency. - Remove unnecessary varible initialization to zero. - Refine the loop of data writing.
drivers/spi/Makefile | 1 + drivers/spi/andes_spi.c | 302 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/spi/andes_spi.h | 128 ++++++++++++++++++++ 3 files changed, 431 insertions(+), 0 deletions(-) create mode 100644 drivers/spi/andes_spi.c create mode 100644 drivers/spi/andes_spi.h
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index d582fbb..8ee8f68 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -26,6 +26,7 @@ include $(TOPDIR)/config.mk LIB := $(obj)libspi.o
COBJS-$(CONFIG_ALTERA_SPI) += altera_spi.o +COBJS-$(CONFIG_ANDES_SPI) += andes_spi.o COBJS-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o COBJS-$(CONFIG_BFIN_SPI) += bfin_spi.o diff --git a/drivers/spi/andes_spi.c b/drivers/spi/andes_spi.c new file mode 100644 index 0000000..fdde139 --- /dev/null +++ b/drivers/spi/andes_spi.c @@ -0,0 +1,302 @@ +/* + * Driver of Andes SPI Controller + * + * (C) Copyright 2011 Andes Technology + * Macpaul Lin macpaul@andestech.com + * + * 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 + */ + +#include <common.h> +#include <malloc.h> +#include <spi.h> + +#include <asm/io.h> +#include "andes_spi.h" + +void spi_init(void) +{ + /* do nothing */ +} + +static void andes_spi_spit_en(struct andes_spi_slave *ds) +{ + unsigned int dcr = readl(&ds->regs->dcr); + + debug("%s: dcr: %x, write value: %x\n", + __func__, dcr, (dcr | ANDES_SPI_DCR_SPIT)); + + writel((dcr | ANDES_SPI_DCR_SPIT), &ds->regs->dcr); +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct andes_spi_slave *ds; + + if (!spi_cs_is_valid(bus, cs)) + return NULL; + + ds = malloc(sizeof(*ds)); + if (!ds) + return NULL; + + ds->slave.bus = bus; + ds->slave.cs = cs; + ds->regs = (struct andes_spi_regs *)CONFIG_SYS_SPI_BASE; + + /* + * The hardware of andes_spi will set its frequency according + * to APB/AHB bus clock. Hence the hardware doesn't allow changing of + * requency and so the user requested speed is always ignored. + */ + ds->freq = max_hz; + + return &ds->slave; +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct andes_spi_slave *ds = to_andes_spi(slave); + + free(ds); +} + +int spi_claim_bus(struct spi_slave *slave) +{ + struct andes_spi_slave *ds = to_andes_spi(slave); + unsigned int apb; + unsigned int baud; + + /* Enable the SPI hardware */ + writel(ANDES_SPI_CR_SPIRST, &ds->regs->cr); + udelay(1000); + + /* setup format */ + baud = ((CONFIG_SYS_CLK_FREQ / CONFIG_SYS_SPI_CLK / 2) - 1) & 0xFF; + + /* + * SPI_CLK = AHB bus clock / ((BAUD + 1)*2) + * BAUD = AHB bus clock / SPI_CLK / 2) - 1 + */ + apb = (readl(&ds->regs->apb) & 0xffffff00) | baud; + writel(apb, &ds->regs->apb); + + /* no interrupts */ + writel(0, &ds->regs->ie); + + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ + struct andes_spi_slave *ds = to_andes_spi(slave); + + /* Disable the SPI hardware */ + writel(ANDES_SPI_CR_SPIRST, &ds->regs->cr); +} + +static int andes_spi_read(struct spi_slave *slave, unsigned int len, + u8 *rxp, unsigned long flags) +{ + struct andes_spi_slave *ds = to_andes_spi(slave); + unsigned int i, left; + unsigned int data; + + debug("%s: slave: %x, len: %d, rxp: %x, flags: %d\n", + __func__, slave, len, rxp, flags); + + debug("%s: data: ", __func__); + while (len > 0) { + left = min(len, 4); + data = readl(&ds->regs->data); + + debug(" "); + for (i = 0; i < left; i++) { + debug("%02x ", data & 0xff); + *rxp++ = data; + data >>= 8; + len--; + } + } + debug("\n"); + + return 0; +} + +static int andes_spi_write(struct spi_slave *slave, unsigned int wlen, + unsigned int rlen, const u8 *txp, unsigned long flags) +{ + struct andes_spi_slave *ds = to_andes_spi(slave); + unsigned int data; + unsigned int i, left; + unsigned int spit_enabled = 0; + + debug("%s: slave: %x, wlen: %d, rlen: %d, txp: %x, flags: %x\n", + __func__, slave, wlen, rlen, txp, flags); + + /* The value of wlen and rlen wrote to register must minus 1 */ + if (rlen == 0) /* write only */ + writel(ANDES_SPI_DCR_MODE_WO | ANDES_SPI_DCR_WCNT(wlen-1) | + ANDES_SPI_DCR_RCNT(0), &ds->regs->dcr); + else /* write then read */ + writel(ANDES_SPI_DCR_MODE_WR | ANDES_SPI_DCR_WCNT(wlen-1) | + ANDES_SPI_DCR_RCNT(rlen-1), &ds->regs->dcr); + + /* wait till SPIBSY is cleared */ + while (readl(&ds->regs->st) & ANDES_SPI_ST_SPIBSY) + ; + + /* data write process */ + debug("%s: txp: ", __func__); + while (wlen > 0) { + /* clear the data */ + data = 0; + + /* data are usually be read 32bits once a time */ + left = min(wlen, 4); + + for (i = 0; i < left; i++) { + debug("%x ", *txp); + data |= *txp++ << (i * 8); + wlen--; + } + debug("\n"); + + debug("data: %08x\n", data); + debug("streg before write: %08x\n", readl(&ds->regs->st)); + /* wait till TXFULL is deasserted */ + while (readl(&ds->regs->st) & ANDES_SPI_ST_TXFEL) + ; + writel(data, &ds->regs->data); + debug("streg after write: %08x\n", readl(&ds->regs->st)); + + + if (spit_enabled == 0) { + /* enable SPIT bit - trigger the tx and rx progress */ + andes_spi_spit_en(ds); + spit_enabled = 1; + } + + } + debug("\n"); + + return 0; +} + +/* + * spi_xfer: + * Since andes_spi doesn't support independent command transaction, + * that is, write and than read must be operated in continuous + * execution, there is no need to set dcr and trigger spit again in + * RX process. + */ +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, + const void *dout, void *din, unsigned long flags) +{ + unsigned int len; + static int op_nextime; + static u8 tmp_cmd[5]; + static int tmp_wlen; + unsigned int i; + + if (bitlen == 0) + /* Finish any previously submitted transfers */ + goto out; + + if (bitlen % 8) { + /* Errors always terminate an ongoing transfer */ + flags |= SPI_XFER_END; + goto out; + } + + len = bitlen / 8; + + debug("%s: slave: %08x, bitlen: %d, dout: " + "%08x, din: %08x, flags: %d, len: %d\n", + __func__, slave, bitlen, dout, din, flags, len); + + /* + * Important: + * andes_spi's hardware doesn't support 2 data channel. The read + * and write cmd/data share the same register (data register). + * + * If a command has write and read transaction, you cannot do write + * this time and then do read on next time. + * + * A command writes first with a read response must indicating + * the read length in write operation. Hence the write action must + * be stored temporary and wait until the next read action has been + * arrived. Then we flush the write and read action out together. + */ + if (!dout) { + if (op_nextime == 1) { + /* flags should be SPI_XFER_END, value is 2 */ + op_nextime = 0; + andes_spi_write(slave, tmp_wlen, len, tmp_cmd, flags); + } + return andes_spi_read(slave, len, din, flags); + } else if (!din) { + if (flags == SPI_XFER_BEGIN) { + /* store the write command and do operation next time */ + op_nextime = 1; + memset(tmp_cmd, 0, sizeof(tmp_cmd)); + memcpy(tmp_cmd, dout, len); + + debug("%s: tmp_cmd: ", __func__); + for (i = 0; i < len; i++) + debug("%x ", *(tmp_cmd + i)); + debug("\n"); + + tmp_wlen = len; + } else { + /* + * flags should be (SPI_XFER_BEGIN | SPI_XFER_END), + * the value is 3. + */ + if (op_nextime == 1) { + /* flags should be SPI_XFER_END, value is 2 */ + op_nextime = 0; + /* flags 3 implies write only */ + andes_spi_write(slave, tmp_wlen, 0, tmp_cmd, 3); + } + + debug("flags: %x\n", flags); + return andes_spi_write(slave, len, 0, dout, flags); + } + } + +out: + return 0; +} + +int spi_cs_is_valid(unsigned int bus, unsigned int cs) +{ + return bus == 0 && cs == 0; +} + +void spi_cs_activate(struct spi_slave *slave) +{ + /* do nothing */ +} + +void spi_cs_deactivate(struct spi_slave *slave) +{ + /* do nothing */ +} diff --git a/drivers/spi/andes_spi.h b/drivers/spi/andes_spi.h new file mode 100644 index 0000000..844bdba --- /dev/null +++ b/drivers/spi/andes_spi.h @@ -0,0 +1,128 @@ +/* + * Register definitions for the Andes SPI Controller + * + * (C) Copyright 2011 Andes Technology + * Macpaul Lin macpaul@andestech.com + * + * 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 + */ + +#ifndef __ANDES_SPI_H +#define __ANDES_SPI_H + +struct andes_spi_regs { + unsigned int apb; /* 0x00 - APB SPI interface setting */ + unsigned int pio; /* 0x04 - PIO reg */ + unsigned int cr; /* 0x08 - SPI Control reg */ + unsigned int st; /* 0x0c - SPI Status reg */ + unsigned int ie; /* 0x10 - Interrupt Enable reg */ + unsigned int ist; /* 0x14 - Interrupt Status reg */ + unsigned int dcr; /* 0x18 - data control reg */ + unsigned int data; /* 0x1c - data register */ + unsigned int ahb; /* 0x20 - AHB SPI interface setting */ + unsigned int ver; /* 0x3c - SPI version reg */ +}; + +#define BIT(x) (1 << (x)) + +/* 0x00 - APB SPI interface setting register */ +#define ANDES_SPI_APB_BAUD(x) (((x) & 0xff) < 0) +#define ANDES_SPI_APB_CSHT(x) (((x) & 0xf) < 16) +#define ANDES_SPI_APB_SPNTS BIT(20) /* 0: normal, 1: delay */ +#define ANDES_SPI_APB_CPHA BIT(24) /* 0: Sampling at odd edges */ +#define ANDES_SPI_APB_CPOL BIT(25) /* 0: SCK low, 1: SCK high */ +#define ANDES_SPI_APB_MSSL BIT(26) /* 0: SPI Master, 1: slave */ + +/* 0x04 - PIO register */ +#define ANDES_SPI_PIO_MISO BIT(0) /* input value of pin MISO */ +#define ANDES_SPI_PIO_MOSI BIT(1) /* I/O value of pin MOSI */ +#define ANDES_SPI_PIO_SCK BIT(2) /* I/O value of pin SCK */ +#define ANDES_SPI_PIO_CS BIT(3) /* I/O value of pin CS */ +#define ANDES_SPI_PIO_PIOE BIT(4) /* Programming IO Enable */ + +/* 0x08 - SPI Control register */ +#define ANDES_SPI_CR_SPIRST BIT(0) /* SPI mode reset */ +#define ANDES_SPI_CR_RXFRST BIT(1) /* RxFIFO reset */ +#define ANDES_SPI_CR_TXFRST BIT(2) /* TxFIFO reset */ +#define ANDES_SPI_CR_RXFTH(x) (((x) & 0x1f) << 10) /* RxFIFO Threshold */ +#define ANDES_SPI_CR_TXFTH(x) (((x) & 0x1f) << 18) /* TxFIFO Threshold */ + +/* 0x0c - SPI Status register */ +#define ANDES_SPI_ST_SPIBSY BIT(0) /* SPI Transfer is active */ +#define ANDES_SPI_ST_RXFEM BIT(8) /* RxFIFO Empty Flag */ +#define ANDES_SPI_ST_RXFEL BIT(9) /* RxFIFO Full Flag */ +#define ANDES_SPI_ST_RXFVE(x) (((x) >> 10) & 0x1f) +#define ANDES_SPI_ST_TXFEM BIT(16) /* TxFIFO Empty Flag */ +#define ANDES_SPI_ST_TXFEL BIT(7) /* TxFIFO Full Flag */ +#define ANDES_SPI_ST_TXFVE(x) (((x) >> 18) & 0x1f) + +/* 0x10 - Interrupt Enable register */ +#define ANDES_SPI_IE_RXFORIE BIT(0) /* RxFIFO overrun intr */ +#define ANDES_SPI_IE_TXFURIE BIT(1) /* TxFOFO underrun intr */ +#define ANDES_SPI_IE_RXFTHIE BIT(2) /* RxFIFO threshold intr */ +#define ANDES_SPI_IE_TXFTHIE BIT(3) /* TxFIFO threshold intr */ +#define ANDES_SPI_IE_SPIEIE BIT(4) /* SPI transmit END intr */ +#define ANDES_SPI_IE_SPCFIE BIT(5) /* AHB/APB TxReq conflict */ + +/* 0x14 - Interrupt Status Register */ +#define ANDES_SPI_IST_RXFORI BIT(0) /* has RxFIFO overrun */ +#define ANDES_SPI_IST_TXFURI BIT(1) /* has TxFOFO underrun */ +#define ANDES_SPI_IST_RXFTHI BIT(2) /* has RxFIFO threshold */ +#define ANDES_SPI_IST_TXFTHI BIT(3) /* has TxFIFO threshold */ +#define ANDES_SPI_IST_SPIEI BIT(4) /* has SPI transmit END */ +#define ANDES_SPI_IST_SPCFI BIT(5) /* has AHB/APB TxReq conflict */ + +/* 0x18 - Data Control Register */ +#define ANDES_SPI_DCR_RCNT(x) (((x) & 0x3ff) << 0) +#define ANDES_SPI_DCR_DYCNT(x) (((x) & 0x7) << 12) +#define ANDES_SPI_DCR_WCNT(x) (((x) & 0x3ff) << 16) +#define ANDES_SPI_DCR_TRAMODE(x) (((x) & 0x7) << 28) +#define ANDES_SPI_DCR_SPIT BIT(31) /* SPI bus trigger */ + +#define ANDES_SPI_DCR_MODE_WRCON ANDES_SPI_DCR_TRAMODE(0) /* w/r at the same time */ +#define ANDES_SPI_DCR_MODE_WO ANDES_SPI_DCR_TRAMODE(1) /* write only */ +#define ANDES_SPI_DCR_MODE_RO ANDES_SPI_DCR_TRAMODE(2) /* read only */ +#define ANDES_SPI_DCR_MODE_WR ANDES_SPI_DCR_TRAMODE(3) /* write, read */ +#define ANDES_SPI_DCR_MODE_RW ANDES_SPI_DCR_TRAMODE(4) /* read, write */ +#define ANDES_SPI_DCR_MODE_WDR ANDES_SPI_DCR_TRAMODE(5) /* write, dummy, read */ +#define ANDES_SPI_DCR_MODE_RDW ANDES_SPI_DCR_TRAMODE(6) /* read, dummy, write */ +#define ANDES_SPI_DCR_MODE_RECEIVE ANDES_SPI_DCR_TRAMODE(7) /* receive */ + +/* 0x20 - AHB SPI interface setting register */ +#define ANDES_SPI_AHB_BAUD(x) (((x) & 0xff) < 0) +#define ANDES_SPI_AHB_CSHT(x) (((x) & 0xf) < 16) +#define ANDES_SPI_AHB_SPNTS BIT(20) /* 0: normal, 1: delay */ +#define ANDES_SPI_AHB_CPHA BIT(24) /* 0: Sampling at odd edges */ +#define ANDES_SPI_AHB_CPOL BIT(25) /* 0: SCK low, 1: SCK high */ +#define ANDES_SPI_AHB_MSSL BIT(26) /* only Master mode */ + +/* 0x3c - Version Register - (Year V.MAJOR.MINOR) */ +#define ANDES_SPI_VER_MINOR(x) (((x) >> 0) & 0xf) +#define ANDES_SPI_VER_MAJOR(x) (((x) >> 8) & 0xf) +#define ANDES_SPI_VER_YEAR(x) (((x) >> 16) & 0xf) + +struct andes_spi_slave { + struct spi_slave slave; + struct andes_spi_regs *regs; + unsigned int freq; +}; + +static inline struct andes_spi_slave *to_andes_spi(struct spi_slave *slave) +{ + return container_of(slave, struct andes_spi_slave, slave); +} + +#endif /* __ANDES_SPI_H */