// SPDX-License-Identifier: GPL-2.0+ /* * spi driver for rockchip * * (C) 2019 Theobroma Systems Design und Consulting GmbH * * (C) Copyright 2015 Google, Inc * * (C) Copyright 2008-2013 Rockchip Electronics * Peter, Software Engineering, . */ #include #include #include #include #include #include #include #include #include #include #include #include "rk_spi.h" /* Change to 1 to output registers at the start of each transaction */ #define DEBUG_RK_SPI 0 struct rockchip_spi_params { /* RXFIFO overruns and TXFIFO underruns stop the master clock */ bool master_manages_fifo; }; struct rockchip_spi_platdata { #if CONFIG_IS_ENABLED(OF_PLATDATA) struct dtd_rockchip_rk3288_spi of_plat; #endif s32 frequency; /* Default clock frequency, -1 for none */ fdt_addr_t base; uint deactivate_delay_us; /* Delay to wait after deactivate */ uint activate_delay_us; /* Delay to wait after activate */ }; struct rockchip_spi_priv { struct rockchip_spi *regs; struct clk clk; unsigned int max_freq; unsigned int mode; ulong last_transaction_us; /* Time of last transaction end */ unsigned int speed_hz; unsigned int last_speed_hz; uint input_rate; }; #define SPI_FIFO_DEPTH 32 static void rkspi_dump_regs(struct rockchip_spi *regs) { debug("ctrl0: \t\t0x%08x\n", readl(®s->ctrlr0)); debug("ctrl1: \t\t0x%08x\n", readl(®s->ctrlr1)); debug("ssienr: \t\t0x%08x\n", readl(®s->enr)); debug("ser: \t\t0x%08x\n", readl(®s->ser)); debug("baudr: \t\t0x%08x\n", readl(®s->baudr)); debug("txftlr: \t\t0x%08x\n", readl(®s->txftlr)); debug("rxftlr: \t\t0x%08x\n", readl(®s->rxftlr)); debug("txflr: \t\t0x%08x\n", readl(®s->txflr)); debug("rxflr: \t\t0x%08x\n", readl(®s->rxflr)); debug("sr: \t\t0x%08x\n", readl(®s->sr)); debug("imr: \t\t0x%08x\n", readl(®s->imr)); debug("isr: \t\t0x%08x\n", readl(®s->isr)); debug("dmacr: \t\t0x%08x\n", readl(®s->dmacr)); debug("dmatdlr: \t0x%08x\n", readl(®s->dmatdlr)); debug("dmardlr: \t0x%08x\n", readl(®s->dmardlr)); } static void rkspi_enable_chip(struct rockchip_spi *regs, bool enable) { writel(enable ? 1 : 0, ®s->enr); } static void rkspi_set_clk(struct rockchip_spi_priv *priv, uint speed) { /* * We should try not to exceed the speed requested by the caller: * when selecting a divider, we need to make sure we round up. */ uint clk_div = DIV_ROUND_UP(priv->input_rate, speed); /* The baudrate register (BAUDR) is defined as a 32bit register where * the upper 16bit are reserved and having 'Fsclk_out' in the lower * 16bits with 'Fsclk_out' defined as follows: * * Fsclk_out = Fspi_clk/ SCKDV * Where SCKDV is any even value between 2 and 65534. */ if (clk_div > 0xfffe) { clk_div = 0xfffe; debug("%s: can't divide down to %d Hz (actual will be %d Hz)\n", __func__, speed, priv->input_rate / clk_div); } /* Round up to the next even 16bit number */ clk_div = (clk_div + 1) & 0xfffe; debug("spi speed %u, div %u\n", speed, clk_div); clrsetbits_le32(&priv->regs->baudr, 0xffff, clk_div); priv->last_speed_hz = speed; } static int rkspi_wait_till_not_busy(struct rockchip_spi *regs) { unsigned long start; start = get_timer(0); while (readl(®s->sr) & SR_BUSY) { if (get_timer(start) > ROCKCHIP_SPI_TIMEOUT_MS) { debug("RK SPI: Status keeps busy for 1000us after a read/write!\n"); return -ETIMEDOUT; } } return 0; } static void spi_cs_activate(struct udevice *dev, uint cs) { struct udevice *bus = dev->parent; struct rockchip_spi_platdata *plat = bus->platdata; struct rockchip_spi_priv *priv = dev_get_priv(bus); struct rockchip_spi *regs = priv->regs; /* If it's too soon to do another transaction, wait */ if (plat->deactivate_delay_us && priv->last_transaction_us) { ulong delay_us; /* The delay completed so far */ delay_us = timer_get_us() - priv->last_transaction_us; if (delay_us < plat->deactivate_delay_us) { ulong additional_delay_us = plat->deactivate_delay_us - delay_us; debug("%s: delaying by %ld us\n", __func__, additional_delay_us); udelay(additional_delay_us); } } debug("activate cs%u\n", cs); writel(1 << cs, ®s->ser); if (plat->activate_delay_us) udelay(plat->activate_delay_us); } static void spi_cs_deactivate(struct udevice *dev, uint cs) { struct udevice *bus = dev->parent; struct rockchip_spi_platdata *plat = bus->platdata; struct rockchip_spi_priv *priv = dev_get_priv(bus); struct rockchip_spi *regs = priv->regs; debug("deactivate cs%u\n", cs); writel(0, ®s->ser); /* Remember time of this transaction so we can honour the bus delay */ if (plat->deactivate_delay_us) priv->last_transaction_us = timer_get_us(); } #if CONFIG_IS_ENABLED(OF_PLATDATA) static int conv_of_platdata(struct udevice *dev) { struct rockchip_spi_platdata *plat = dev->platdata; struct dtd_rockchip_rk3288_spi *dtplat = &plat->of_plat; struct rockchip_spi_priv *priv = dev_get_priv(dev); int ret; plat->base = dtplat->reg[0]; plat->frequency = 20000000; ret = clk_get_by_index_platdata(dev, 0, dtplat->clocks, &priv->clk); if (ret < 0) return ret; dev->req_seq = 0; return 0; } #endif static int rockchip_spi_ofdata_to_platdata(struct udevice *bus) { #if !CONFIG_IS_ENABLED(OF_PLATDATA) struct rockchip_spi_platdata *plat = dev_get_platdata(bus); struct rockchip_spi_priv *priv = dev_get_priv(bus); int ret; plat->base = dev_read_addr(bus); ret = clk_get_by_index(bus, 0, &priv->clk); if (ret < 0) { debug("%s: Could not get clock for %s: %d\n", __func__, bus->name, ret); return ret; } plat->frequency = dev_read_u32_default(bus, "spi-max-frequency", 50000000); plat->deactivate_delay_us = dev_read_u32_default(bus, "spi-deactivate-delay", 0); plat->activate_delay_us = dev_read_u32_default(bus, "spi-activate-delay", 0); debug("%s: base=%x, max-frequency=%d, deactivate_delay=%d\n", __func__, (uint)plat->base, plat->frequency, plat->deactivate_delay_us); #endif return 0; } static int rockchip_spi_calc_modclk(ulong max_freq) { /* * While this is not strictly correct for the RK3368, as the * GPLL will be 576MHz, things will still work, as the * clk_set_rate(...) implementation in our clock-driver will * chose the next closest rate not exceeding what we request * based on the output of this function. */ unsigned div; const unsigned long gpll_hz = 594000000UL; /* * We need to find an input clock that provides at least twice * the maximum frequency and can be generated from the assumed * speed of GPLL (594MHz) using an integer divider. * * To give us more achievable bitrates at higher speeds (these * are generated by dividing by an even 16-bit integer from * this frequency), we try to have an input frequency of at * least 4x our max_freq. */ div = DIV_ROUND_UP(gpll_hz, max_freq * 4); return gpll_hz / div; } static int rockchip_spi_probe(struct udevice *bus) { struct rockchip_spi_platdata *plat = dev_get_platdata(bus); struct rockchip_spi_priv *priv = dev_get_priv(bus); int ret; debug("%s: probe\n", __func__); #if CONFIG_IS_ENABLED(OF_PLATDATA) ret = conv_of_platdata(bus); if (ret) return ret; #endif priv->regs = (struct rockchip_spi *)plat->base; priv->last_transaction_us = timer_get_us(); priv->max_freq = plat->frequency; /* Clamp the value from the DTS against any hardware limits */ if (priv->max_freq > ROCKCHIP_SPI_MAX_RATE) priv->max_freq = ROCKCHIP_SPI_MAX_RATE; /* Find a module-input clock that fits with the max_freq setting */ ret = clk_set_rate(&priv->clk, rockchip_spi_calc_modclk(priv->max_freq)); if (ret < 0) { debug("%s: Failed to set clock: %d\n", __func__, ret); return ret; } priv->input_rate = ret; debug("%s: rate = %u\n", __func__, priv->input_rate); return 0; } static int rockchip_spi_claim_bus(struct udevice *dev) { struct udevice *bus = dev->parent; struct rockchip_spi_priv *priv = dev_get_priv(bus); struct rockchip_spi *regs = priv->regs; uint ctrlr0; /* Disable the SPI hardware */ rkspi_enable_chip(regs, false); if (priv->speed_hz != priv->last_speed_hz) rkspi_set_clk(priv, priv->speed_hz); /* Operation Mode */ ctrlr0 = OMOD_MASTER << OMOD_SHIFT; /* Data Frame Size */ ctrlr0 |= DFS_8BIT << DFS_SHIFT; /* set SPI mode 0..3 */ if (priv->mode & SPI_CPOL) ctrlr0 |= SCOL_HIGH << SCOL_SHIFT; if (priv->mode & SPI_CPHA) ctrlr0 |= SCPH_TOGSTA << SCPH_SHIFT; /* Chip Select Mode */ ctrlr0 |= CSM_KEEP << CSM_SHIFT; /* SSN to Sclk_out delay */ ctrlr0 |= SSN_DELAY_ONE << SSN_DELAY_SHIFT; /* Serial Endian Mode */ ctrlr0 |= SEM_LITTLE << SEM_SHIFT; /* First Bit Mode */ ctrlr0 |= FBM_MSB << FBM_SHIFT; /* Byte and Halfword Transform */ ctrlr0 |= HALF_WORD_OFF << HALF_WORD_TX_SHIFT; /* Rxd Sample Delay */ ctrlr0 |= 0 << RXDSD_SHIFT; /* Frame Format */ ctrlr0 |= FRF_SPI << FRF_SHIFT; /* Tx and Rx mode */ ctrlr0 |= TMOD_TR << TMOD_SHIFT; writel(ctrlr0, ®s->ctrlr0); return 0; } static int rockchip_spi_release_bus(struct udevice *dev) { struct udevice *bus = dev->parent; struct rockchip_spi_priv *priv = dev_get_priv(bus); rkspi_enable_chip(priv->regs, false); 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; } /* * If we know that the hardware will manage RXFIFO overruns * (i.e. stop the SPI clock until there's space in the FIFO), * we the allow largest possible chunk size that can be * represented in CTRLR1. */ if (data && data->master_manages_fifo) max_chunk_size = 0x10000; // 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) { struct udevice *bus = dev->parent; struct rockchip_spi_priv *priv = dev_get_priv(bus); struct rockchip_spi *regs = priv->regs; struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev); int len = bitlen >> 3; const u8 *out = dout; u8 *in = din; int toread, towrite; int ret = 0; debug("%s: dout=%p, din=%p, len=%x, flags=%lx\n", __func__, dout, din, len, flags); if (DEBUG_RK_SPI) rkspi_dump_regs(regs); /* Assert CS before transfer */ 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); rkspi_enable_chip(regs, false); writel(todo - 1, ®s->ctrlr1); rkspi_enable_chip(regs, true); toread = todo; towrite = todo; while (toread || towrite) { u32 status = readl(®s->sr); if (towrite && !(status & SR_TF_FULL)) { writel(out ? *out++ : 0, regs->txdr); towrite--; } if (toread && !(status & SR_RF_EMPT)) { u32 byte = readl(regs->rxdr); if (in) *in++ = byte; toread--; } } /* * In case that there's a transmit-component, we need to wait * until the control goes idle before we can disable the SPI * control logic (as this will implictly flush the FIFOs). */ if (out) { ret = rkspi_wait_till_not_busy(regs); if (ret) break; } len -= todo; } /* Deassert CS after transfer */ if (flags & SPI_XFER_END) spi_cs_deactivate(dev, slave_plat->cs); rkspi_enable_chip(regs, false); return ret; } static int rockchip_spi_set_speed(struct udevice *bus, uint speed) { struct rockchip_spi_priv *priv = dev_get_priv(bus); /* Clamp to the maximum frequency specified in the DTS */ if (speed > priv->max_freq) speed = priv->max_freq; priv->speed_hz = speed; return 0; } static int rockchip_spi_set_mode(struct udevice *bus, uint mode) { struct rockchip_spi_priv *priv = dev_get_priv(bus); priv->mode = mode; return 0; } static const struct dm_spi_ops rockchip_spi_ops = { .claim_bus = rockchip_spi_claim_bus, .release_bus = rockchip_spi_release_bus, .xfer = rockchip_spi_xfer, .set_speed = rockchip_spi_set_speed, .set_mode = rockchip_spi_set_mode, /* * cs_info is not needed, since we require all chip selects to be * in the device tree explicitly */ }; const struct rockchip_spi_params rk3399_spi_params = { .master_manages_fifo = true, }; static const struct udevice_id rockchip_spi_ids[] = { { .compatible = "rockchip,rk3288-spi" }, { .compatible = "rockchip,rk3368-spi", .data = (ulong)&rk3399_spi_params }, { .compatible = "rockchip,rk3399-spi", .data = (ulong)&rk3399_spi_params }, { } }; U_BOOT_DRIVER(rockchip_spi) = { #if CONFIG_IS_ENABLED(OF_PLATDATA) .name = "rockchip_rk3288_spi", #else .name = "rockchip_spi", #endif .id = UCLASS_SPI, .of_match = rockchip_spi_ids, .ops = &rockchip_spi_ops, .ofdata_to_platdata = rockchip_spi_ofdata_to_platdata, .platdata_auto_alloc_size = sizeof(struct rockchip_spi_platdata), .priv_auto_alloc_size = sizeof(struct rockchip_spi_priv), .probe = rockchip_spi_probe, };