diff options
Diffstat (limited to 'drivers/spi/mpc8xxx_spi.c')
| -rw-r--r-- | drivers/spi/mpc8xxx_spi.c | 141 |
1 files changed, 81 insertions, 60 deletions
diff --git a/drivers/spi/mpc8xxx_spi.c b/drivers/spi/mpc8xxx_spi.c index 1c7bf10f91..1bde31ad34 100644 --- a/drivers/spi/mpc8xxx_spi.c +++ b/drivers/spi/mpc8xxx_spi.c @@ -5,6 +5,7 @@ */ #include <common.h> +#include <clk.h> #include <dm.h> #include <errno.h> #include <malloc.h> @@ -27,6 +28,8 @@ enum { SPI_MODE_EN = BIT(31 - 7), /* Enable interface */ SPI_MODE_LEN_MASK = 0xf00000, + SPI_MODE_LEN_SHIFT = 20, + SPI_MODE_PM_SHIFT = 16, SPI_MODE_PM_MASK = 0xf0000, SPI_COM_LST = BIT(31 - 9), @@ -35,46 +38,38 @@ enum { struct mpc8xxx_priv { spi8xxx_t *spi; struct gpio_desc gpios[16]; - int max_cs; + int cs_count; + ulong clk_rate; }; -static inline u32 to_prescale_mod(u32 val) -{ - return (min(val, (u32)15) << 16); -} - -static void set_char_len(spi8xxx_t *spi, u32 val) -{ - clrsetbits_be32(&spi->mode, SPI_MODE_LEN_MASK, (val << 20)); -} - #define SPI_TIMEOUT 1000 -static int __spi_set_speed(spi8xxx_t *spi, uint speed) -{ - /* TODO(mario.six@gdsys.cc): This only ever sets one fixed speed */ - - /* Use SYSCLK / 8 (16.67MHz typ.) */ - clrsetbits_be32(&spi->mode, SPI_MODE_PM_MASK, to_prescale_mod(1)); - - return 0; -} - static int mpc8xxx_spi_ofdata_to_platdata(struct udevice *dev) { struct mpc8xxx_priv *priv = dev_get_priv(dev); + struct clk clk; int ret; priv->spi = (spi8xxx_t *)dev_read_addr(dev); - /* TODO(mario.six@gdsys.cc): Read clock and save the value */ - ret = gpio_request_list_by_name(dev, "gpios", priv->gpios, ARRAY_SIZE(priv->gpios), GPIOD_IS_OUT | GPIOD_ACTIVE_LOW); if (ret < 0) return -EINVAL; - priv->max_cs = ret; + priv->cs_count = ret; + + ret = clk_get_by_index(dev, 0, &clk); + if (ret) { + dev_err(dev, "%s: clock not defined\n", __func__); + return ret; + } + + priv->clk_rate = clk_get_rate(&clk); + if (!priv->clk_rate) { + dev_err(dev, "%s: failed to get clock rate\n", __func__); + return -EINVAL; + } return 0; } @@ -82,14 +77,18 @@ static int mpc8xxx_spi_ofdata_to_platdata(struct udevice *dev) static int mpc8xxx_spi_probe(struct udevice *dev) { struct mpc8xxx_priv *priv = dev_get_priv(dev); + spi8xxx_t *spi = priv->spi; /* * SPI pins on the MPC83xx are not muxed, so all we do is initialize * some registers */ - out_be32(&priv->spi->mode, SPI_MODE_REV | SPI_MODE_MS | SPI_MODE_EN); + out_be32(&priv->spi->mode, SPI_MODE_REV | SPI_MODE_MS); + + /* set len to 8 bits */ + setbits_be32(&spi->mode, (8 - 1) << SPI_MODE_LEN_SHIFT); - __spi_set_speed(priv->spi, 16666667); + setbits_be32(&spi->mode, SPI_MODE_EN); /* Clear all SPI events */ setbits_be32(&priv->spi->event, 0xffffffff); @@ -126,45 +125,35 @@ static int mpc8xxx_spi_xfer(struct udevice *dev, uint bitlen, struct mpc8xxx_priv *priv = dev_get_priv(bus); spi8xxx_t *spi = priv->spi; struct dm_spi_slave_platdata *platdata = dev_get_parent_platdata(dev); - u32 tmpdin = 0; - int num_blks = DIV_ROUND_UP(bitlen, 32); + u32 tmpdin = 0, tmpdout = 0, n; + const u8 *cout = dout; + u8 *cin = din; debug("%s: slave %s:%u dout %08X din %08X bitlen %u\n", __func__, - bus->name, platdata->cs, *(uint *)dout, *(uint *)din, bitlen); + bus->name, platdata->cs, (uint)dout, (uint)din, bitlen); + if (platdata->cs >= priv->cs_count) { + dev_err(dev, "chip select index %d too large (cs_count=%d)\n", + platdata->cs, priv->cs_count); + return -EINVAL; + } + if (bitlen % 8) { + printf("*** spi_xfer: bitlen must be multiple of 8\n"); + return -ENOTSUPP; + } if (flags & SPI_XFER_BEGIN) mpc8xxx_spi_cs_activate(dev); /* Clear all SPI events */ setbits_be32(&spi->event, 0xffffffff); + n = bitlen / 8; - /* Handle data in 32-bit chunks */ - while (num_blks--) { - u32 tmpdout = 0; - uchar xfer_bitlen = (bitlen >= 32 ? 32 : bitlen); + /* Handle data in 8-bit chunks */ + while (n--) { ulong start; - clrbits_be32(&spi->mode, SPI_MODE_EN); - - /* Set up length for this transfer */ - - if (bitlen <= 4) /* 4 bits or less */ - set_char_len(spi, 3); - else if (bitlen <= 16) /* at most 16 bits */ - set_char_len(spi, bitlen - 1); - else /* more than 16 bits -> full 32 bit transfer */ - set_char_len(spi, 0); - - setbits_be32(&spi->mode, SPI_MODE_EN); - - /* Shift data so it's msb-justified */ - tmpdout = *(u32 *)dout >> (32 - xfer_bitlen); - - if (bitlen > 32) { - /* Set up the next iteration if sending > 32 bits */ - bitlen -= 32; - dout += 4; - } + if (cout) + tmpdout = *cout++; /* Write the data out */ out_be32(&spi->tx, tmpdout); @@ -188,11 +177,8 @@ static int mpc8xxx_spi_xfer(struct udevice *dev, uint bitlen, tmpdin = in_be32(&spi->rx); setbits_be32(&spi->event, SPI_EV_NE); - *(u32 *)din = (tmpdin << (32 - xfer_bitlen)); - if (xfer_bitlen == 32) { - /* Advance output buffer by 32 bits */ - din += 4; - } + if (cin) + *cin++ = tmpdin; /* * Only bail when we've had both NE and NF events. @@ -224,8 +210,43 @@ static int mpc8xxx_spi_xfer(struct udevice *dev, uint bitlen, static int mpc8xxx_spi_set_speed(struct udevice *dev, uint speed) { struct mpc8xxx_priv *priv = dev_get_priv(dev); + spi8xxx_t *spi = priv->spi; + u32 bits, mask, div16, pm; + u32 mode; + ulong clk; + + clk = priv->clk_rate; + if (clk / 64 > speed) { + div16 = SPI_MODE_DIV16; + clk /= 16; + } else { + div16 = 0; + } + pm = (clk - 1)/(4*speed) + 1; + if (pm > 16) { + dev_err(dev, "requested speed %u too small\n", speed); + return -EINVAL; + } + pm--; + + bits = div16 | (pm << SPI_MODE_PM_SHIFT); + mask = SPI_MODE_DIV16 | SPI_MODE_PM_MASK; + mode = in_be32(&spi->mode); + if ((mode & mask) != bits) { + /* Must clear mode[EN] while changing speed. */ + mode &= ~(mask | SPI_MODE_EN); + out_be32(&spi->mode, mode); + mode |= bits; + out_be32(&spi->mode, mode); + mode |= SPI_MODE_EN; + out_be32(&spi->mode, mode); + } - return __spi_set_speed(priv->spi, speed); + debug("requested speed %u, set speed to %lu/(%s4*%u) == %lu\n", + speed, priv->clk_rate, div16 ? "16*" : "", pm + 1, + clk/(4*(pm + 1))); + + return 0; } static int mpc8xxx_spi_set_mode(struct udevice *dev, uint mode) |