MXC SPI driver has a feature whereas a GPIO line can be used to force CS high across multiple transactions. This is set up by embedding the GPIO information in the CS value: cs = (cs | gpio << 8) This merge of cs and gpio data into one value breaks the sf probe command: if the use of gpio is required, invoking "sf probe <cs>" will not work, because the CS argument doesn't have the GPIO information in it. Instead, the user must use "sf probe <cs | gpio << 8>". For example, if bank 2 gpio 30 is used to force cs high on cs 0, bus 0, then instead of typing "sf probe 0" the user now must type "sf probe 15872". This is inconsistent with the description of the sf probe command, and forces the user to be aware of implementaiton details. Fix this by introducing a new board function: board_spi_cs_gpio(), which will accept a naked CS value, and provide the driver with the relevant GPIO, if one is necessary. Cc: Eric Nelson <eric.nelson@boundarydevices.com> Cc: Eric Benard <eric@eukrea.com> Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Tim Harvey <tharvey@gateworks.com> Cc: Stefano Babic <sbabic@denx.de> Cc: Tom Rini <trini@ti.com> Cc: Marek Vasut <marex@denx.de> Reviewed-by: Marek Vasut <marex@denx.de> Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il> Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
464 lines
10 KiB
C
464 lines
10 KiB
C
/*
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* Copyright (C) 2008, Guennadi Liakhovetski <lg@denx.de>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <malloc.h>
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#include <spi.h>
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#include <asm/errno.h>
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#include <asm/io.h>
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#include <asm/gpio.h>
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#include <asm/arch/imx-regs.h>
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#include <asm/arch/clock.h>
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#ifdef CONFIG_MX27
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/* i.MX27 has a completely wrong register layout and register definitions in the
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* datasheet, the correct one is in the Freescale's Linux driver */
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#error "i.MX27 CSPI not supported due to drastic differences in register definitions" \
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"See linux mxc_spi driver from Freescale for details."
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#endif
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static unsigned long spi_bases[] = {
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MXC_SPI_BASE_ADDRESSES
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};
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__weak int board_spi_cs_gpio(unsigned bus, unsigned cs)
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{
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return -1;
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}
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#define OUT MXC_GPIO_DIRECTION_OUT
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#define reg_read readl
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#define reg_write(a, v) writel(v, a)
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#if !defined(CONFIG_SYS_SPI_MXC_WAIT)
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#define CONFIG_SYS_SPI_MXC_WAIT (CONFIG_SYS_HZ/100) /* 10 ms */
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#endif
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struct mxc_spi_slave {
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struct spi_slave slave;
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unsigned long base;
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u32 ctrl_reg;
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#if defined(MXC_ECSPI)
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u32 cfg_reg;
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#endif
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int gpio;
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int ss_pol;
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};
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static inline struct mxc_spi_slave *to_mxc_spi_slave(struct spi_slave *slave)
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{
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return container_of(slave, struct mxc_spi_slave, slave);
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}
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void spi_cs_activate(struct spi_slave *slave)
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{
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struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
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if (mxcs->gpio > 0)
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gpio_set_value(mxcs->gpio, mxcs->ss_pol);
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}
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void spi_cs_deactivate(struct spi_slave *slave)
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{
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struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
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if (mxcs->gpio > 0)
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gpio_set_value(mxcs->gpio,
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!(mxcs->ss_pol));
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}
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u32 get_cspi_div(u32 div)
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{
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int i;
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for (i = 0; i < 8; i++) {
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if (div <= (4 << i))
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return i;
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}
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return i;
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}
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#ifdef MXC_CSPI
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static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
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unsigned int max_hz, unsigned int mode)
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{
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unsigned int ctrl_reg;
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u32 clk_src;
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u32 div;
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clk_src = mxc_get_clock(MXC_CSPI_CLK);
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div = DIV_ROUND_UP(clk_src, max_hz);
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div = get_cspi_div(div);
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debug("clk %d Hz, div %d, real clk %d Hz\n",
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max_hz, div, clk_src / (4 << div));
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ctrl_reg = MXC_CSPICTRL_CHIPSELECT(cs) |
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MXC_CSPICTRL_BITCOUNT(MXC_CSPICTRL_MAXBITS) |
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MXC_CSPICTRL_DATARATE(div) |
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MXC_CSPICTRL_EN |
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#ifdef CONFIG_MX35
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MXC_CSPICTRL_SSCTL |
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#endif
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MXC_CSPICTRL_MODE;
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if (mode & SPI_CPHA)
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ctrl_reg |= MXC_CSPICTRL_PHA;
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if (mode & SPI_CPOL)
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ctrl_reg |= MXC_CSPICTRL_POL;
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if (mode & SPI_CS_HIGH)
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ctrl_reg |= MXC_CSPICTRL_SSPOL;
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mxcs->ctrl_reg = ctrl_reg;
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return 0;
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}
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#endif
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#ifdef MXC_ECSPI
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static s32 spi_cfg_mxc(struct mxc_spi_slave *mxcs, unsigned int cs,
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unsigned int max_hz, unsigned int mode)
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{
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u32 clk_src = mxc_get_clock(MXC_CSPI_CLK);
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s32 reg_ctrl, reg_config;
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u32 ss_pol = 0, sclkpol = 0, sclkpha = 0, sclkctl = 0;
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u32 pre_div = 0, post_div = 0;
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struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
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if (max_hz == 0) {
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printf("Error: desired clock is 0\n");
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return -1;
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}
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/*
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* Reset SPI and set all CSs to master mode, if toggling
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* between slave and master mode we might see a glitch
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* on the clock line
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*/
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reg_ctrl = MXC_CSPICTRL_MODE_MASK;
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reg_write(®s->ctrl, reg_ctrl);
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reg_ctrl |= MXC_CSPICTRL_EN;
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reg_write(®s->ctrl, reg_ctrl);
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if (clk_src > max_hz) {
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pre_div = (clk_src - 1) / max_hz;
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/* fls(1) = 1, fls(0x80000000) = 32, fls(16) = 5 */
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post_div = fls(pre_div);
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if (post_div > 4) {
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post_div -= 4;
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if (post_div >= 16) {
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printf("Error: no divider for the freq: %d\n",
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max_hz);
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return -1;
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}
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pre_div >>= post_div;
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} else {
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post_div = 0;
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}
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}
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debug("pre_div = %d, post_div=%d\n", pre_div, post_div);
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reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_SELCHAN(3)) |
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MXC_CSPICTRL_SELCHAN(cs);
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reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_PREDIV(0x0F)) |
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MXC_CSPICTRL_PREDIV(pre_div);
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reg_ctrl = (reg_ctrl & ~MXC_CSPICTRL_POSTDIV(0x0F)) |
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MXC_CSPICTRL_POSTDIV(post_div);
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/* We need to disable SPI before changing registers */
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reg_ctrl &= ~MXC_CSPICTRL_EN;
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if (mode & SPI_CS_HIGH)
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ss_pol = 1;
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if (mode & SPI_CPOL) {
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sclkpol = 1;
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sclkctl = 1;
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}
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if (mode & SPI_CPHA)
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sclkpha = 1;
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reg_config = reg_read(®s->cfg);
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/*
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* Configuration register setup
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* The MX51 supports different setup for each SS
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*/
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reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_SSPOL))) |
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(ss_pol << (cs + MXC_CSPICON_SSPOL));
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reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_POL))) |
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(sclkpol << (cs + MXC_CSPICON_POL));
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reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_CTL))) |
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(sclkctl << (cs + MXC_CSPICON_CTL));
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reg_config = (reg_config & ~(1 << (cs + MXC_CSPICON_PHA))) |
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(sclkpha << (cs + MXC_CSPICON_PHA));
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debug("reg_ctrl = 0x%x\n", reg_ctrl);
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reg_write(®s->ctrl, reg_ctrl);
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debug("reg_config = 0x%x\n", reg_config);
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reg_write(®s->cfg, reg_config);
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/* save config register and control register */
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mxcs->ctrl_reg = reg_ctrl;
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mxcs->cfg_reg = reg_config;
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/* clear interrupt reg */
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reg_write(®s->intr, 0);
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reg_write(®s->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
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return 0;
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}
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#endif
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int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
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const u8 *dout, u8 *din, unsigned long flags)
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{
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struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
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int nbytes = DIV_ROUND_UP(bitlen, 8);
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u32 data, cnt, i;
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struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
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u32 ts;
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int status;
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debug("%s: bitlen %d dout 0x%x din 0x%x\n",
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__func__, bitlen, (u32)dout, (u32)din);
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mxcs->ctrl_reg = (mxcs->ctrl_reg &
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~MXC_CSPICTRL_BITCOUNT(MXC_CSPICTRL_MAXBITS)) |
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MXC_CSPICTRL_BITCOUNT(bitlen - 1);
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reg_write(®s->ctrl, mxcs->ctrl_reg | MXC_CSPICTRL_EN);
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#ifdef MXC_ECSPI
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reg_write(®s->cfg, mxcs->cfg_reg);
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#endif
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/* Clear interrupt register */
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reg_write(®s->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
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/*
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* The SPI controller works only with words,
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* check if less than a word is sent.
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* Access to the FIFO is only 32 bit
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*/
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if (bitlen % 32) {
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data = 0;
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cnt = (bitlen % 32) / 8;
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if (dout) {
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for (i = 0; i < cnt; i++) {
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data = (data << 8) | (*dout++ & 0xFF);
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}
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}
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debug("Sending SPI 0x%x\n", data);
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reg_write(®s->txdata, data);
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nbytes -= cnt;
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}
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data = 0;
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while (nbytes > 0) {
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data = 0;
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if (dout) {
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/* Buffer is not 32-bit aligned */
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if ((unsigned long)dout & 0x03) {
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data = 0;
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for (i = 0; i < 4; i++)
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data = (data << 8) | (*dout++ & 0xFF);
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} else {
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data = *(u32 *)dout;
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data = cpu_to_be32(data);
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dout += 4;
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}
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}
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debug("Sending SPI 0x%x\n", data);
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reg_write(®s->txdata, data);
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nbytes -= 4;
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}
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/* FIFO is written, now starts the transfer setting the XCH bit */
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reg_write(®s->ctrl, mxcs->ctrl_reg |
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MXC_CSPICTRL_EN | MXC_CSPICTRL_XCH);
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ts = get_timer(0);
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status = reg_read(®s->stat);
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/* Wait until the TC (Transfer completed) bit is set */
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while ((status & MXC_CSPICTRL_TC) == 0) {
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if (get_timer(ts) > CONFIG_SYS_SPI_MXC_WAIT) {
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printf("spi_xchg_single: Timeout!\n");
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return -1;
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}
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status = reg_read(®s->stat);
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}
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/* Transfer completed, clear any pending request */
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reg_write(®s->stat, MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
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nbytes = DIV_ROUND_UP(bitlen, 8);
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cnt = nbytes % 32;
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if (bitlen % 32) {
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data = reg_read(®s->rxdata);
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cnt = (bitlen % 32) / 8;
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data = cpu_to_be32(data) >> ((sizeof(data) - cnt) * 8);
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debug("SPI Rx unaligned: 0x%x\n", data);
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if (din) {
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memcpy(din, &data, cnt);
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din += cnt;
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}
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nbytes -= cnt;
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}
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while (nbytes > 0) {
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u32 tmp;
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tmp = reg_read(®s->rxdata);
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data = cpu_to_be32(tmp);
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debug("SPI Rx: 0x%x 0x%x\n", tmp, data);
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cnt = min(nbytes, sizeof(data));
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if (din) {
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memcpy(din, &data, cnt);
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din += cnt;
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}
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nbytes -= cnt;
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}
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return 0;
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}
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int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
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void *din, unsigned long flags)
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{
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int n_bytes = DIV_ROUND_UP(bitlen, 8);
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int n_bits;
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int ret;
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u32 blk_size;
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u8 *p_outbuf = (u8 *)dout;
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u8 *p_inbuf = (u8 *)din;
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if (!slave)
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return -1;
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if (flags & SPI_XFER_BEGIN)
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spi_cs_activate(slave);
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while (n_bytes > 0) {
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if (n_bytes < MAX_SPI_BYTES)
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blk_size = n_bytes;
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else
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blk_size = MAX_SPI_BYTES;
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n_bits = blk_size * 8;
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ret = spi_xchg_single(slave, n_bits, p_outbuf, p_inbuf, 0);
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if (ret)
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return ret;
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if (dout)
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p_outbuf += blk_size;
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if (din)
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p_inbuf += blk_size;
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n_bytes -= blk_size;
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}
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if (flags & SPI_XFER_END) {
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spi_cs_deactivate(slave);
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}
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return 0;
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}
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void spi_init(void)
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{
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}
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/*
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* Some SPI devices require active chip-select over multiple
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* transactions, we achieve this using a GPIO. Still, the SPI
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* controller has to be configured to use one of its own chipselects.
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* To use this feature you have to implement board_spi_cs_gpio() to assign
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* a gpio value for each cs (-1 if cs doesn't need to use gpio).
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* You must use some unused on this SPI controller cs between 0 and 3.
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*/
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static int setup_cs_gpio(struct mxc_spi_slave *mxcs,
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unsigned int bus, unsigned int cs)
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{
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int ret;
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mxcs->gpio = board_spi_cs_gpio(bus, cs);
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if (mxcs->gpio == -1)
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return 0;
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ret = gpio_direction_output(mxcs->gpio, !(mxcs->ss_pol));
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if (ret) {
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printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio);
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return -EINVAL;
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}
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return 0;
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}
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struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
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unsigned int max_hz, unsigned int mode)
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{
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struct mxc_spi_slave *mxcs;
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int ret;
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if (bus >= ARRAY_SIZE(spi_bases))
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return NULL;
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mxcs = spi_alloc_slave(struct mxc_spi_slave, bus, cs);
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if (!mxcs) {
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puts("mxc_spi: SPI Slave not allocated !\n");
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return NULL;
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}
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mxcs->ss_pol = (mode & SPI_CS_HIGH) ? 1 : 0;
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ret = setup_cs_gpio(mxcs, bus, cs);
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if (ret < 0) {
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free(mxcs);
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return NULL;
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}
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mxcs->base = spi_bases[bus];
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ret = spi_cfg_mxc(mxcs, cs, max_hz, mode);
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if (ret) {
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printf("mxc_spi: cannot setup SPI controller\n");
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free(mxcs);
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return NULL;
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}
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return &mxcs->slave;
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}
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void spi_free_slave(struct spi_slave *slave)
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{
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struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
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free(mxcs);
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}
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int spi_claim_bus(struct spi_slave *slave)
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{
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struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
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struct cspi_regs *regs = (struct cspi_regs *)mxcs->base;
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reg_write(®s->rxdata, 1);
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udelay(1);
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reg_write(®s->ctrl, mxcs->ctrl_reg);
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reg_write(®s->period, MXC_CSPIPERIOD_32KHZ);
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reg_write(®s->intr, 0);
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return 0;
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}
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void spi_release_bus(struct spi_slave *slave)
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{
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/* TODO: Shut the controller down */
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}
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