X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=drivers%2Fspi%2Fmxc_spi.c;h=f3f029d634abd1f2045c20ba3e159bc1aecf7e4a;hb=019b57cc1d280c3768e2e8a7ff22e07a64c2f670;hp=2e1531858d32f8ab1f6b02fd5a9ac2e171387fa5;hpb=5c877b1ae0a4219ed6bd8d32cf3f7106b81ecb3b;p=u-boot diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c index 2e1531858d..f3f029d634 100644 --- a/drivers/spi/mxc_spi.c +++ b/drivers/spi/mxc_spi.c @@ -1,21 +1,7 @@ /* * Copyright (C) 2008, Guennadi Liakhovetski * - * 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 - * + * SPDX-License-Identifier: GPL-2.0+ */ #include @@ -96,7 +82,7 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs, clk_src = mxc_get_clock(MXC_CSPI_CLK); - div = clk_src / max_hz; + div = DIV_ROUND_UP(clk_src, max_hz); div = get_cspi_div(div); debug("clk %d Hz, div %d, real clk %d Hz\n", @@ -128,8 +114,9 @@ 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 pre_div = 0, post_div = 0, i, reg_ctrl, reg_config; - u32 ss_pol = 0, sclkpol = 0, sclkpha = 0; + 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) { @@ -137,32 +124,30 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs, return -1; } - reg_ctrl = reg_read(®s->ctrl); - - /* Reset spi */ - reg_write(®s->ctrl, 0); - reg_write(®s->ctrl, (reg_ctrl | 0x1)); - /* - * The following computation is taken directly from Freescale's code. + * 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 / max_hz; - if (pre_div > 16) { - post_div = pre_div / 16; - pre_div = 15; - } - if (post_div != 0) { - for (i = 0; i < 16; i++) { - if ((1 << i) >= post_div) - break; - } - if (i == 16) { + 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; } - post_div = i; + pre_div >>= post_div; + } else { + post_div = 0; } } @@ -174,17 +159,16 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs, reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_POSTDIV(0x0F)) | MXC_CSPICTRL_POSTDIV(post_div); - /* always set to master mode */ - reg_ctrl |= 1 << (cs + 4); - /* 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) + if (mode & SPI_CPOL) { sclkpol = 1; + sclkctl = 1; + } if (mode & SPI_CPHA) sclkpha = 1; @@ -199,6 +183,8 @@ static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs, (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)); @@ -223,7 +209,7 @@ 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 = (bitlen + 7) / 8; + int nbytes = DIV_ROUND_UP(bitlen, 8); u32 data, cnt, i; struct cspi_regs *regs = (struct cspi_regs *)mxcs->base; @@ -274,8 +260,8 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen, } else { data = *(u32 *)dout; data = cpu_to_be32(data); + dout += 4; } - dout += 4; } debug("Sending SPI 0x%x\n", data); reg_write(®s->txdata, data); @@ -293,7 +279,7 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen, /* Transfer completed, clear any pending request */ reg_write(®s->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF); - nbytes = (bitlen + 7) / 8; + nbytes = DIV_ROUND_UP(bitlen, 8); cnt = nbytes % 32; @@ -329,7 +315,7 @@ int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen, int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, void *din, unsigned long flags) { - int n_bytes = (bitlen + 7) / 8; + int n_bytes = DIV_ROUND_UP(bitlen, 8); int n_bits; int ret; u32 blk_size; @@ -387,7 +373,7 @@ static int decode_cs(struct mxc_spi_slave *mxcs, unsigned int cs) if (cs > 3) { mxcs->gpio = cs >> 8; cs &= 3; - ret = gpio_direction_output(mxcs->gpio, 0); + ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol)); if (ret) { printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio); return -EINVAL; @@ -408,12 +394,14 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, if (bus >= ARRAY_SIZE(spi_bases)) return NULL; - mxcs = malloc(sizeof(struct mxc_spi_slave)); + 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); @@ -422,10 +410,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, cs = ret; - mxcs->slave.bus = bus; - mxcs->slave.cs = cs; mxcs->base = spi_bases[bus]; - mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0; ret = spi_cfg_mxc(mxcs, cs, max_hz, mode); if (ret) {