X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Froms%2Fu-boot%2Fdrivers%2Fspi%2Fmxc_spi.c;fp=qemu%2Froms%2Fu-boot%2Fdrivers%2Fspi%2Fmxc_spi.c;h=f3f029d634abd1f2045c20ba3e159bc1aecf7e4a;hb=e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb;hp=0000000000000000000000000000000000000000;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git diff --git a/qemu/roms/u-boot/drivers/spi/mxc_spi.c b/qemu/roms/u-boot/drivers/spi/mxc_spi.c new file mode 100644 index 000000000..f3f029d63 --- /dev/null +++ b/qemu/roms/u-boot/drivers/spi/mxc_spi.c @@ -0,0 +1,448 @@ +/* + * Copyright (C) 2008, Guennadi Liakhovetski + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_MX27 +/* i.MX27 has a completely wrong register layout and register definitions in the + * datasheet, the correct one is in the Freescale's Linux driver */ + +#error "i.MX27 CSPI not supported due to drastic differences in register definitions" \ +"See linux mxc_spi driver from Freescale for details." +#endif + +static unsigned long spi_bases[] = { + MXC_SPI_BASE_ADDRESSES +}; + +#define OUT MXC_GPIO_DIRECTION_OUT + +#define reg_read readl +#define reg_write(a, v) writel(v, a) + +struct mxc_spi_slave { + struct spi_slave slave; + unsigned long base; + u32 ctrl_reg; +#if defined(MXC_ECSPI) + u32 cfg_reg; +#endif + int gpio; + int ss_pol; +}; + +static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave) +{ + return container_of(slave, struct mxc_spi_slave, slave); +} + +void spi_cs_activate(struct spi_slave *slave) +{ + struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave); + if (mxcs->gpio > 0) + gpio_set_value(mxcs->gpio, mxcs->ss_pol); +} + +void spi_cs_deactivate(struct spi_slave *slave) +{ + struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave); + if (mxcs->gpio > 0) + gpio_set_value(mxcs->gpio, + !(mxcs->ss_pol)); +} + +u32 get_cspi_div(u32 div) +{ + int i; + + for (i = 0; i < 8; i++) { + if (div <= (4 << i)) + return i; + } + return i; +} + +#ifdef MXC_CSPI +static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + unsigned int ctrl_reg; + u32 clk_src; + u32 div; + + clk_src = mxc_get_clock(MXC_CSPI_CLK); + + div = DIV_ROUND_UP(clk_src, max_hz); + div = get_cspi_div(div); + + debug("clk %d Hz, div %d, real clk %d Hz\n", + max_hz, div, clk_src / (4 << div)); + + ctrl_reg = MXC_CSPICTRL_CHIPSELECT(cs) | + MXC_CSPICTRL_BITCOUNT(MXC_CSPICTRL_MAXBITS) | + MXC_CSPICTRL_DATARATE(div) | + MXC_CSPICTRL_EN | +#ifdef CONFIG_MX35 + MXC_CSPICTRL_SSCTL | +#endif + MXC_CSPICTRL_MODE; + + if (mode & SPI_CPHA) + ctrl_reg |= MXC_CSPICTRL_PHA; + if (mode & SPI_CPOL) + ctrl_reg |= MXC_CSPICTRL_POL; + if (mode & SPI_CS_HIGH) + ctrl_reg |= MXC_CSPICTRL_SSPOL; + mxcs->ctrl_reg = ctrl_reg; + + return 0; +} +#endif + +#ifdef MXC_ECSPI +static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + u32 clk_src = mxc_get_clock(MXC_CSPI_CLK); + s32 reg_ctrl, reg_config; + u32 ss_pol = 0, sclkpol = 0, sclkpha = 0, sclkctl = 0; + u32 pre_div = 0, post_div = 0; + struct cspi_regs *regs = (struct cspi_regs *)mxcs->base; + + if (max_hz == 0) { + printf("Error: desired clock is 0\n"); + return -1; + } + + /* + * Reset SPI and set all CSs to master mode, if toggling + * between slave and master mode we might see a glitch + * on the clock line + */ + reg_ctrl = MXC_CSPICTRL_MODE_MASK; + reg_write(®s->ctrl, reg_ctrl); + reg_ctrl |= MXC_CSPICTRL_EN; + reg_write(®s->ctrl, reg_ctrl); + + if (clk_src > max_hz) { + pre_div = (clk_src - 1) / max_hz; + /* fls(1) = 1, fls(0x80000000) = 32, fls(16) = 5 */ + post_div = fls(pre_div); + if (post_div > 4) { + post_div -= 4; + if (post_div >= 16) { + printf("Error: no divider for the freq: %d\n", + max_hz); + return -1; + } + pre_div >>= post_div; + } else { + post_div = 0; + } + } + + debug("pre_div = %d, post_div=%d\n", pre_div, post_div); + reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_SELCHAN(3)) | + MXC_CSPICTRL_SELCHAN(cs); + reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_PREDIV(0x0F)) | + MXC_CSPICTRL_PREDIV(pre_div); + reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_POSTDIV(0x0F)) | + MXC_CSPICTRL_POSTDIV(post_div); + + /* We need to disable SPI before changing registers */ + reg_ctrl &= ~MXC_CSPICTRL_EN; + + if (mode & SPI_CS_HIGH) + ss_pol = 1; + + if (mode & SPI_CPOL) { + sclkpol = 1; + sclkctl = 1; + } + + if (mode & SPI_CPHA) + sclkpha = 1; + + reg_config = reg_read(®s->cfg); + + /* + * Configuration register setup + * The MX51 supports different setup for each SS + */ + reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_SSPOL))) | + (ss_pol << (cs + MXC_CSPICON_SSPOL)); + reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_POL))) | + (sclkpol << (cs + MXC_CSPICON_POL)); + reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_CTL))) | + (sclkctl << (cs + MXC_CSPICON_CTL)); + reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_PHA))) | + (sclkpha << (cs + MXC_CSPICON_PHA)); + + debug("reg_ctrl = 0x%x\n", reg_ctrl); + reg_write(®s->ctrl, reg_ctrl); + debug("reg_config = 0x%x\n", reg_config); + reg_write(®s->cfg, reg_config); + + /* save config register and control register */ + mxcs->ctrl_reg = reg_ctrl; + mxcs->cfg_reg = reg_config; + + /* clear interrupt reg */ + reg_write(®s->intr, 0); + reg_write(®s->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF); + + return 0; +} +#endif + +int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen, + const u8 *dout, u8 *din, unsigned long flags) +{ + struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave); + int nbytes = DIV_ROUND_UP(bitlen, 8); + u32 data, cnt, i; + struct cspi_regs *regs = (struct cspi_regs *)mxcs->base; + + debug("%s: bitlen %d dout 0x%x din 0x%x\n", + __func__, bitlen, (u32)dout, (u32)din); + + mxcs->ctrl_reg = (mxcs->ctrl_reg & + ~MXC_CSPICTRL_BITCOUNT(MXC_CSPICTRL_MAXBITS)) | + MXC_CSPICTRL_BITCOUNT(bitlen - 1); + + reg_write(®s->ctrl, mxcs->ctrl_reg | MXC_CSPICTRL_EN); +#ifdef MXC_ECSPI + reg_write(®s->cfg, mxcs->cfg_reg); +#endif + + /* Clear interrupt register */ + reg_write(®s->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF); + + /* + * The SPI controller works only with words, + * check if less than a word is sent. + * Access to the FIFO is only 32 bit + */ + if (bitlen % 32) { + data = 0; + cnt = (bitlen % 32) / 8; + if (dout) { + for (i = 0; i < cnt; i++) { + data = (data << 8) | (*dout++ & 0xFF); + } + } + debug("Sending SPI 0x%x\n", data); + + reg_write(®s->txdata, data); + nbytes -= cnt; + } + + data = 0; + + while (nbytes > 0) { + data = 0; + if (dout) { + /* Buffer is not 32-bit aligned */ + if ((unsigned long)dout & 0x03) { + data = 0; + for (i = 0; i < 4; i++) + data = (data << 8) | (*dout++ & 0xFF); + } else { + data = *(u32 *)dout; + data = cpu_to_be32(data); + dout += 4; + } + } + debug("Sending SPI 0x%x\n", data); + reg_write(®s->txdata, data); + nbytes -= 4; + } + + /* FIFO is written, now starts the transfer setting the XCH bit */ + reg_write(®s->ctrl, mxcs->ctrl_reg | + MXC_CSPICTRL_EN | MXC_CSPICTRL_XCH); + + /* Wait until the TC (Transfer completed) bit is set */ + while ((reg_read(®s->stat) & MXC_CSPICTRL_TC) == 0) + ; + + /* Transfer completed, clear any pending request */ + reg_write(®s->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF); + + nbytes = DIV_ROUND_UP(bitlen, 8); + + cnt = nbytes % 32; + + if (bitlen % 32) { + data = reg_read(®s->rxdata); + cnt = (bitlen % 32) / 8; + data = cpu_to_be32(data) >> ((sizeof(data) - cnt) * 8); + debug("SPI Rx unaligned: 0x%x\n", data); + if (din) { + memcpy(din, &data, cnt); + din += cnt; + } + nbytes -= cnt; + } + + while (nbytes > 0) { + u32 tmp; + tmp = reg_read(®s->rxdata); + data = cpu_to_be32(tmp); + debug("SPI Rx: 0x%x 0x%x\n", tmp, data); + cnt = min(nbytes, sizeof(data)); + if (din) { + memcpy(din, &data, cnt); + din += cnt; + } + nbytes -= cnt; + } + + return 0; + +} + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, + void *din, unsigned long flags) +{ + int n_bytes = DIV_ROUND_UP(bitlen, 8); + int n_bits; + int ret; + u32 blk_size; + u8 *p_outbuf = (u8 *)dout; + u8 *p_inbuf = (u8 *)din; + + if (!slave) + return -1; + + if (flags & SPI_XFER_BEGIN) + spi_cs_activate(slave); + + while (n_bytes > 0) { + if (n_bytes < MAX_SPI_BYTES) + blk_size = n_bytes; + else + blk_size = MAX_SPI_BYTES; + + n_bits = blk_size * 8; + + ret = spi_xchg_single(slave, n_bits, p_outbuf, p_inbuf, 0); + + if (ret) + return ret; + if (dout) + p_outbuf += blk_size; + if (din) + p_inbuf += blk_size; + n_bytes -= blk_size; + } + + if (flags & SPI_XFER_END) { + spi_cs_deactivate(slave); + } + + return 0; +} + +void spi_init(void) +{ +} + +static int decode_cs(struct mxc_spi_slave *mxcs, unsigned int cs) +{ + int ret; + + /* + * Some SPI devices require active chip-select over multiple + * transactions, we achieve this using a GPIO. Still, the SPI + * controller has to be configured to use one of its own chipselects. + * To use this feature you have to call spi_setup_slave() with + * cs = internal_cs | (gpio << 8), and you have to use some unused + * on this SPI controller cs between 0 and 3. + */ + if (cs > 3) { + mxcs->gpio = cs >> 8; + cs &= 3; + ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol)); + if (ret) { + printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio); + return -EINVAL; + } + } else { + mxcs->gpio = -1; + } + + return cs; +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct mxc_spi_slave *mxcs; + int ret; + + if (bus >= ARRAY_SIZE(spi_bases)) + return NULL; + + mxcs = spi_alloc_slave(struct mxc_spi_slave, bus, cs); + if (!mxcs) { + puts("mxc_spi: SPI Slave not allocated !\n"); + return NULL; + } + + mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0; + + ret = decode_cs(mxcs, cs); + if (ret < 0) { + free(mxcs); + return NULL; + } + + cs = ret; + + mxcs->base = spi_bases[bus]; + + ret = spi_cfg_mxc(mxcs, cs, max_hz, mode); + if (ret) { + printf("mxc_spi: cannot setup SPI controller\n"); + free(mxcs); + return NULL; + } + return &mxcs->slave; +} + +void spi_free_slave(struct spi_slave *slave) +{ + struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave); + + free(mxcs); +} + +int spi_claim_bus(struct spi_slave *slave) +{ + struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave); + struct cspi_regs *regs = (struct cspi_regs *)mxcs->base; + + reg_write(®s->rxdata, 1); + udelay(1); + reg_write(®s->ctrl, mxcs->ctrl_reg); + reg_write(®s->period, MXC_CSPIPERIOD_32KHZ); + reg_write(®s->intr, 0); + + return 0; +} + +void spi_release_bus(struct spi_slave *slave) +{ + /* TODO: Shut the controller down */ +}