diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/spi/rk_spi.c | 89 |
1 files changed, 88 insertions, 1 deletions
diff --git a/drivers/spi/rk_spi.c b/drivers/spi/rk_spi.c index c807d78185..fec41a4243 100644 --- a/drivers/spi/rk_spi.c +++ b/drivers/spi/rk_spi.c @@ -2,6 +2,8 @@ /* * spi driver for rockchip * + * (C) 2019 Theobroma Systems Design und Consulting GmbH + * * (C) Copyright 2015 Google, Inc * * (C) Copyright 2008-2013 Rockchip Electronics @@ -333,6 +335,81 @@ static int rockchip_spi_release_bus(struct udevice *dev) return 0; } +static inline int rockchip_spi_16bit_reader(struct udevice *dev, + u8 **din, int *len) +{ + struct udevice *bus = dev->parent; + const struct rockchip_spi_params * const data = + (void *)dev_get_driver_data(bus); + struct rockchip_spi_priv *priv = dev_get_priv(bus); + struct rockchip_spi *regs = priv->regs; + const u32 saved_ctrlr0 = readl(®s->ctrlr0); +#if defined(DEBUG) + u32 statistics_rxlevels[33] = { }; +#endif + u32 frames = *len / 2; + u16 *in16 = (u16 *)(*din); + u32 max_chunk_size = SPI_FIFO_DEPTH; + + if (!frames) + return 0; + + /* + * If the destination buffer is unaligned, we'd run into a problem + * on ARMv8. Given that this doesn't seem to be a real issue, we + * just chicken out and fall back to the unoptimised implementation. + */ + if ((uintptr_t)*din & 1) { + debug("%s: unaligned buffer, din = %p\n", __func__, *din); + return 0; + } + + // rockchip_spi_configure(dev, mode, size) + rkspi_enable_chip(regs, false); + clrsetbits_le32(®s->ctrlr0, + TMOD_MASK << TMOD_SHIFT, + TMOD_RO << TMOD_SHIFT); + /* 16bit data frame size */ + clrsetbits_le32(®s->ctrlr0, DFS_MASK, DFS_16BIT); + + /* Update caller's context */ + const u32 bytes_to_process = 2 * frames; + *din += bytes_to_process; + *len -= bytes_to_process; + + /* Process our frames */ + while (frames) { + u32 chunk_size = min(frames, max_chunk_size); + + frames -= chunk_size; + + writew(chunk_size - 1, ®s->ctrlr1); + rkspi_enable_chip(regs, true); + + do { + u32 rx_level = readw(®s->rxflr); +#if defined(DEBUG) + statistics_rxlevels[rx_level]++; +#endif + chunk_size -= rx_level; + while (rx_level--) + *in16++ = readw(regs->rxdr); + } while (chunk_size); + + rkspi_enable_chip(regs, false); + } + +#if defined(DEBUG) + debug("%s: observed rx_level during processing:\n", __func__); + for (int i = 0; i <= 32; ++i) + if (statistics_rxlevels[i]) + debug("\t%2d: %d\n", i, statistics_rxlevels[i]); +#endif + /* Restore the original transfer setup and return error-free. */ + writel(saved_ctrlr0, ®s->ctrlr0); + return 0; +} + static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen, const void *dout, void *din, unsigned long flags) { @@ -344,7 +421,7 @@ static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen, const u8 *out = dout; u8 *in = din; int toread, towrite; - int ret; + int ret = 0; debug("%s: dout=%p, din=%p, len=%x, flags=%lx\n", __func__, dout, din, len, flags); @@ -355,6 +432,16 @@ static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen, if (flags & SPI_XFER_BEGIN) spi_cs_activate(dev, slave_plat->cs); + /* + * To ensure fast loading of firmware images (e.g. full U-Boot + * stage, ATF, Linux kernel) from SPI flash, we optimise the + * case of read-only transfers by using the full 16bits of each + * FIFO element. + */ + if (!out) + ret = rockchip_spi_16bit_reader(dev, &in, &len); + + /* This is the original 8bit reader/writer code */ while (len > 0) { int todo = min(len, 0x10000); |