[U-Boot] [PATCH] SPI: added support for MX51 to mxc_spi
Tom
Tom.Rix at windriver.com
Sun Mar 21 01:14:48 CET 2010
Stefano Babic wrote:
> This patch add support for MX51 processor and
> supports transfer of multiple word in a single
> transation.
>
> Signed-off-by: Stefano Babic <sbabic at denx.de>
> ---
>
> The patch adds support for the MX51 and wants to remove some
> limitation on the old driver. Actually, the buffer passed
> to the transfer function must be word-aligne, even if it is
> required to send a single byte.
It may be better to split this patch into
1. fixing the old driver
2. adding mx51
>
> drivers/spi/mxc_spi.c | 357 +++++++++++++++++++++++++++++++++++++++++--------
> 1 files changed, 301 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c
> index 3a45200..b04fadc 100644
> --- a/drivers/spi/mxc_spi.c
> +++ b/drivers/spi/mxc_spi.c
> @@ -24,6 +24,11 @@
> #include <asm/errno.h>
> #include <asm/io.h>
>
> +#define MXC_CSPIRXDATA 0x00
> +#define MXC_CSPITXDATA 0x04
> +#define MXC_CSPICTRL 0x08
> +#define MXC_CSPIPERIOD_32KHZ (1 << 15)
> +
Pulling these out and making them common may not be the best thing to do.
Located here, it hides the
#ifdef CONFIG_MX27
#elif defined (CONFIG_MX31)
#elif defined (CONFIG_MX51)
#else
#endif
I would prefer if you just kept the copies in the mx31, mx51 locations
> #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 */
> @@ -31,13 +36,9 @@
> #error "i.MX27 CSPI not supported due to drastic differences in register definisions" \
> "See linux mxc_spi driver from Freescale for details."
>
> -#else
> -
> +#elif defined(CONFIG_MX31)
> #include <asm/arch/mx31.h>
>
> -#define MXC_CSPIRXDATA 0x00
> -#define MXC_CSPITXDATA 0x04
> -#define MXC_CSPICTRL 0x08
> #define MXC_CSPIINT 0x0C
> #define MXC_CSPIDMA 0x10
> #define MXC_CSPISTAT 0x14
> @@ -56,21 +57,63 @@
> #define MXC_CSPICTRL_CHIPSELECT(x) (((x) & 0x3) << 24)
> #define MXC_CSPICTRL_BITCOUNT(x) (((x) & 0x1f) << 8)
> #define MXC_CSPICTRL_DATARATE(x) (((x) & 0x7) << 16)
> +#define MXC_CSPICTRL_MAXBITS 0x1f
> +#define MXC_CSPICTRL_TC (1 << 8)
> +#define MXC_CSPICTRL_RXOVF (1 << 6)
>
> #define MXC_CSPIPERIOD_32KHZ (1 << 15)
> +#define MAX_SPI_BYTES 4
In 'Add SPI support to mx51evk board'
The MAX_SPI_BYTES was defined in the config file.
Here it is defined for mx31 generally.
You should be consistent.
These would be a better place for the mx51 values as you only have to do it once.
>
> static unsigned long spi_bases[] = {
> 0x43fa4000,
> 0x50010000,
> 0x53f84000,
> };
> +#elif defined(CONFIG_MX51)
> +
> +#define MXC_CSPICON 0x0C
> +#define MXC_CSPIINT 0x10
> +#define MXC_CSPIDMA 0x14
> +#define MXC_CSPISTAT 0x18
> +#define MXC_CSPIPERIOD 0x1C
> +#define MXC_CSPIRESET 0x00
>
> +#include <asm/arch/imx-regs.h>
> +#include <asm/arch/clock.h>
Be constistent with mx31
Move the #includes to the first lines after the #elif
The other #defines to follow.
Tom
> +#define MXC_CSPICTRL_EN (1 << 0)
> +#define MXC_CSPICTRL_MODE (1 << 1)
> +#define MXC_CSPICTRL_XCH (1 << 2)
> +#define MXC_CSPICTRL_CHIPSELECT(x) (((x) & 0x3) << 12)
> +#define MXC_CSPICTRL_BITCOUNT(x) (((x) & 0xfff) << 20)
> +#define MXC_CSPICTRL_PREDIV(x) (((x) & 0xF) << 12)
> +#define MXC_CSPICTRL_POSTDIV(x) (((x) & 0xF) << 8)
> +#define MXC_CSPICTRL_SELCHAN(x) (((x) & 0x3) << 18)
> +#define MXC_CSPICTRL_MAXBITS 0xfff
> +#define MXC_CSPICTRL_TC (1 << 7)
> +#define MXC_CSPICTRL_RXOVF (1 << 6)
> +
> +/* Bit position inside CTRL register to be associated with SS */
> +#define MXC_CSPICTRL_CHAN 18
> +
> +/* Bit position inside CON register to be associated with SS */
> +#define MXC_CSPICON_POL 4
> +#define MXC_CSPICON_PHA 0
> +#define MXC_CSPICON_SSPOL 12
> +
> +static unsigned long spi_bases[] = {
> + CSPI1_BASE_ADDR,
> + CSPI2_BASE_ADDR,
> + CSPI3_BASE_ADDR,
> +};
> +#else
> +#error "Unsupported architecture"
> #endif
>
> struct mxc_spi_slave {
> struct spi_slave slave;
> unsigned long base;
> u32 ctrl_reg;
> + u32 cfg_reg;
> int gpio;
> };
>
> @@ -89,71 +132,262 @@ static inline void reg_write(unsigned long addr, u32 val)
> *(volatile unsigned long*)addr = val;
> }
>
> -static u32 spi_xchg_single(struct spi_slave *slave, u32 data, int bitlen,
> - unsigned long flags)
> +void spi_cs_activate(struct spi_slave *slave)
> {
> +#ifdef CONFIG_MX31
> struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
> - unsigned int cfg_reg = reg_read(mxcs->base + MXC_CSPICTRL);
> -
> - mxcs->ctrl_reg = (mxcs->ctrl_reg & ~MXC_CSPICTRL_BITCOUNT(31)) |
> - MXC_CSPICTRL_BITCOUNT(bitlen - 1);
> + if (mxcs->gpio > 0)
> + mx31_gpio_set(mxcs->gpio, mxcs->ctrl_reg & MXC_CSPICTRL_SSPOL);
> +#endif
> +}
>
> - if (cfg_reg != mxcs->ctrl_reg)
> - reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg);
> +void spi_cs_deactivate(struct spi_slave *slave)
> +{
> + struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
> +#ifdef CONFIG_MX31
> + if (mxcs->gpio > 0)
> + mx31_gpio_set(mxcs->gpio,
> + !(mxcs->ctrl_reg & MXC_CSPICTRL_SSPOL));
> +#endif
> + reg_write(mxcs->base + MXC_CSPICTRL, 0);
> +}
>
> - if (mxcs->gpio > 0 && (flags & SPI_XFER_BEGIN))
> - mx31_gpio_set(mxcs->gpio, mxcs->ctrl_reg & MXC_CSPICTRL_SSPOL);
> +static s32 spi_cfg(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;
>
> - reg_write(mxcs->base + MXC_CSPITXDATA, data);
> + if (max_hz == 0) {
> + printf("Error: desired clock is 0\n");
> + return -1;
> + }
>
> - reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg | MXC_CSPICTRL_XCH);
> + reg_ctrl = reg_read(mxcs->base + MXC_CSPICTRL);
>
> - while (reg_read(mxcs->base + MXC_CSPICTRL) & MXC_CSPICTRL_XCH)
> - ;
> + /* Reset spi */
> + reg_write(mxcs->base + MXC_CSPICTRL, 0);
> + reg_write(mxcs->base + MXC_CSPICTRL, (reg_ctrl | 0x1));
>
> - if (mxcs->gpio > 0 && (flags & SPI_XFER_END)) {
> - mx31_gpio_set(mxcs->gpio,
> - !(mxcs->ctrl_reg & MXC_CSPICTRL_SSPOL));
> + /*
> + * The following computation is taken directly from Freescale's code.
> + */
> + 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) {
> + printf("Error: no divider for the freq: %d\n",
> + max_hz);
> + return -1;
> + }
> + post_div = i;
> + }
> }
>
> - return reg_read(mxcs->base + MXC_CSPIRXDATA);
> + 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);
> +
> + /* 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))
> + sclkpol = 1;
> +
> + if (mode & SPI_CPHA)
> + sclkpha = 1;
> +
> + reg_config = reg_read(mxcs->base + MXC_CSPICON);
> +
> + /*
> + * Configuration register setup
> + * The MX51 has support 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_PHA))) |
> + (sclkpha << (cs + MXC_CSPICON_PHA));
> +
> + debug("reg_ctrl = 0x%x\n", reg_ctrl);
> + reg_write(mxcs->base + MXC_CSPICTRL, reg_ctrl);
> + debug("reg_config = 0x%x\n", reg_config);
> + reg_write(mxcs->base + MXC_CSPICON, reg_config);
> +
> + /* save config register and control register */
> + mxcs->ctrl_reg = reg_ctrl;
> + mxcs->cfg_reg = reg_config;
> +
> + /* clear interrupt reg */
> + reg_write(mxcs->base + MXC_CSPIINT, 0);
> + reg_write(mxcs->base + MXC_CSPISTAT,
> + MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
> +
> + return 0;
> }
>
> -int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
> - void *din, unsigned long flags)
> +static int spi_xchg_single(struct spi_slave *slave, unsigned int bitlen,
> + const void *dout, void *din, unsigned long flags)
> {
> - int n_blks = (bitlen + 31) / 32;
> - u32 *out_l, *in_l;
> - int i;
> + struct mxc_spi_slave *mxcs = to_mxc_spi_slave(slave);
> + int n_bytes = (bitlen + 7) / 8;
> + int n_blks = (n_bytes + 3) / 4;
> + int cnt_blk;
> + u32 tmpdata;
> + u32 spare_bytes = 0;
> + int j;
> + char *pbuf;
> +
> + debug("spi_xchg: %d %d %d\n", bitlen, n_bytes, n_blks);
> +
> + if (flags & SPI_XFER_BEGIN)
> + spi_cs_activate(slave);
> +
> + mxcs->ctrl_reg = (mxcs->ctrl_reg &
> + ~MXC_CSPICTRL_BITCOUNT(MXC_CSPICTRL_MAXBITS)) |
> + MXC_CSPICTRL_BITCOUNT(n_bytes * 8 - 1);
> +
> + /* Enable SPI controller */
> + reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg | MXC_CSPICTRL_EN);
> +#ifdef CONFIG_MX51
> + reg_write(mxcs->base + MXC_CSPICON, mxcs->cfg_reg);
> +#endif
>
> - if ((int)dout & 3 || (int)din & 3) {
> - printf("Error: unaligned buffers in: %p, out: %p\n", din, dout);
> - return 1;
> + /* Clear interrupt register */
> + reg_write(mxcs->base + MXC_CSPISTAT,
> + MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
> +
> + for (cnt_blk = 0, pbuf = (char *)dout; cnt_blk < n_blks; cnt_blk++) {
> + tmpdata = 0;
> + for (j = 0; j < 4; j++) {
> + /*
> + * According to the User Manual, only the n
> + * least-significant bits in the first word
> + * will be shifted out. The remaining bits
> + * in first word will be ignored
> + */
> + if (n_bytes > 0) {
> + /*
> + * Check for the first word. If the number of
> + * bytes is not multiple of a word, only a
> + * part of the first word is shifted out
> + * and must be written in TX FIFO.
> + * For example, sending 5 bytes means to write
> + * a single byte first, followed by 4 words.
> + */
> + if ((cnt_blk == 0) && (bitlen % 32) &&
> + (j >= ((bitlen % 32) / 8))) {
> + continue;
> + }
> + if (pbuf)
> + tmpdata = *pbuf++ | (tmpdata << 8);
> + n_bytes--;
> + }
> + }
> + debug("writing TX FIFO 0x%x\n", tmpdata);
> + reg_write(mxcs->base + MXC_CSPITXDATA, tmpdata);
> }
>
> - /* This driver is currently partly broken, alert the user */
> - if (bitlen > 16 && (bitlen % 32)) {
> - printf("Error: SPI transfer with bitlen=%d is broken.\n",
> - bitlen);
> - return 1;
> - }
> + /* FIFO is written, now starts the transfer setting the XCH bit */
> + reg_write(mxcs->base + MXC_CSPICTRL, mxcs->ctrl_reg |
> + MXC_CSPICTRL_EN | MXC_CSPICTRL_XCH);
> +
> + /* Wait until the TC (Transfer completed) bit is set */
> + while ((reg_read(mxcs->base + MXC_CSPISTAT) & MXC_CSPICTRL_TC) == 0)
> + ;
> +
> + /* Transfer completed, clear any pending request */
> + reg_write(mxcs->base + MXC_CSPISTAT,
> + MXC_CSPICTRL_TC | MXC_CSPICTRL_RXOVF);
>
> - for (i = 0, in_l = (u32 *)din, out_l = (u32 *)dout;
> - i < n_blks;
> - i++, in_l++, out_l++, bitlen -= 32) {
> - u32 data = spi_xchg_single(slave, *out_l, bitlen, flags);
> -
> - /* Check if we're only transfering 8 or 16 bits */
> - if (!i) {
> - if (bitlen < 9)
> - *(u8 *)din = data;
> - else if (bitlen < 17)
> - *(u16 *)din = data;
> - else
> - *in_l = data;
> + /*
> + * Now do the opposite: copy only part of the first word
> + * if the number of bytes is not multiple of a word size.
> + */
> + n_bytes = (bitlen + 7) / 8;
> + for (cnt_blk = 0, pbuf = (char *)din; n_bytes > 0; cnt_blk++) {
> + tmpdata = reg_read(mxcs->base + MXC_CSPIRXDATA);
> + debug("value_read 0x%x\n", tmpdata);
> + for (j = 0; j < 4; j++) {
> + if (n_bytes > 0) {
> + /*
> + * If it is the first word, compute how many
> + * bytes must be copied
> + */
> + if (cnt_blk == 0)
> + spare_bytes = (bitlen % 32) / 8;
> +
> + if ((cnt_blk == 0) && (bitlen % 32) &&
> + (j >= spare_bytes))
> + continue;
> +
> + if (din)
> + *pbuf++ = (tmpdata >>
> + ((3 - spare_bytes - j) * 8))
> + & 0xFF;
> +
> + n_bytes--;
> + }
> }
> }
>
> + if (flags & SPI_XFER_END)
> + spi_cs_deactivate(slave);
> +
> + return 0;
> +}
> +
> +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_bits;
> + int ret;
> + u32 blk_size;
> + char *p_outbuf = (char *)dout;
> + char *p_inbuf = (char *)din;
> +
> + if (!slave)
> + return -1;
> +
> + 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, dout, din, flags);
> + if (ret)
> + return ret;
> + if (dout)
> + p_outbuf += blk_size;
> + if (din)
> + p_inbuf += blk_size;
> + n_bytes -= blk_size;
> + }
> +
> return 0;
> }
>
> @@ -163,8 +397,7 @@ void spi_init(void)
>
> static int decode_cs(struct mxc_spi_slave *mxcs, unsigned int cs)
> {
> - int ret;
> -
> + int ret = 0;
> /*
> * Some SPI devices require active chip-select over multiple
> * transactions, we achieve this using a GPIO. Still, the SPI
> @@ -176,11 +409,13 @@ static int decode_cs(struct mxc_spi_slave *mxcs, unsigned int cs)
> if (cs > 3) {
> mxcs->gpio = cs >> 8;
> cs &= 3;
> +#ifdef CONFIG_MX31
> ret = mx31_gpio_direction(mxcs->gpio, MX31_GPIO_DIRECTION_OUT);
> if (ret) {
> printf("mxc_spi: cannot setup gpio %d\n", mxcs->gpio);
> return -EINVAL;
> }
> +#endif
> } else {
> mxcs->gpio = -1;
> }
> @@ -191,7 +426,6 @@ static int decode_cs(struct mxc_spi_slave *mxcs, unsigned int cs)
> struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
> unsigned int max_hz, unsigned int mode)
> {
> - unsigned int ctrl_reg;
> struct mxc_spi_slave *mxcs;
> int ret;
>
> @@ -210,6 +444,19 @@ 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];
> +
> +#ifdef CONFIG_MX51
> + /* Can be used for i.MX31 too ? */
> + ret = spi_cfg(mxcs, cs, max_hz, mode);
> + if (ret) {
> + printf("mxc_spi: cannot setup SPI controller\n");
> + free(mxcs);
> + return NULL;
> + }
> +#else
> ctrl_reg = MXC_CSPICTRL_CHIPSELECT(cs) |
> MXC_CSPICTRL_BITCOUNT(31) |
> MXC_CSPICTRL_DATARATE(7) | /* FIXME: calculate data rate */
> @@ -223,10 +470,8 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
> if (mode & SPI_CS_HIGH)
> ctrl_reg |= MXC_CSPICTRL_SSPOL;
>
> - mxcs->slave.bus = bus;
> - mxcs->slave.cs = cs;
> - mxcs->base = spi_bases[bus];
> mxcs->ctrl_reg = ctrl_reg;
> +#endif
>
> return &mxcs->slave;
> }
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