diff options
Diffstat (limited to 'drivers/spi/rk_spi.c')
| -rw-r--r-- | drivers/spi/rk_spi.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/spi/rk_spi.c b/drivers/spi/rk_spi.c new file mode 100644 index 00000000000..5e0c6ad278f --- /dev/null +++ b/drivers/spi/rk_spi.c @@ -0,0 +1,374 @@ +/* + * spi driver for rockchip + * + * (C) Copyright 2015 Google, Inc + * + * (C) Copyright 2008-2013 Rockchip Electronics + * Peter, Software Engineering, <superpeter.cai@gmail.com>. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <clk.h> +#include <dm.h> +#include <errno.h> +#include <spi.h> +#include <asm/errno.h> +#include <asm/io.h> +#include <asm/arch/clock.h> +#include <asm/arch/periph.h> +#include <dm/pinctrl.h> +#include "rk_spi.h" + +DECLARE_GLOBAL_DATA_PTR; + +/* Change to 1 to output registers at the start of each transaction */ +#define DEBUG_RK_SPI 0 + +struct rockchip_spi_platdata { + enum periph_id periph_id; + struct udevice *pinctrl; + s32 frequency; /* Default clock frequency, -1 for none */ + fdt_addr_t base; + uint deactivate_delay_us; /* Delay to wait after deactivate */ +}; + +struct rockchip_spi_priv { + struct rockchip_spi *regs; + struct udevice *clk_gpll; + unsigned int max_freq; + unsigned int mode; + enum periph_id periph_id; /* Peripheral ID for this device */ + ulong last_transaction_us; /* Time of last transaction end */ + u8 bits_per_word; /* max 16 bits per word */ + u8 n_bytes; + unsigned int speed_hz; + unsigned int tmode; + 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) +{ + uint clk_div; + + clk_div = clk_get_divisor(priv->input_rate, speed); + debug("spi speed %u, div %u\n", speed, clk_div); + + writel(clk_div, &priv->regs->baudr); +} + +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 rockchip_spi *regs, uint cs) +{ + debug("activate cs%u\n", cs); + writel(1 << cs, ®s->ser); +} + +static void spi_cs_deactivate(struct rockchip_spi *regs, uint cs) +{ + debug("deactivate cs%u\n", cs); + writel(0, ®s->ser); +} + +static int rockchip_spi_ofdata_to_platdata(struct udevice *bus) +{ + struct rockchip_spi_platdata *plat = bus->platdata; + const void *blob = gd->fdt_blob; + int node = bus->of_offset; + int ret; + + plat->base = dev_get_addr(bus); + ret = uclass_get_device(UCLASS_PINCTRL, 0, &plat->pinctrl); + if (ret) + return ret; + ret = pinctrl_get_periph_id(plat->pinctrl, bus); + + if (ret < 0) { + debug("%s: Could not get peripheral ID for %s: %d\n", __func__, + bus->name, ret); + return -FDT_ERR_NOTFOUND; + } + plat->periph_id = ret; + + plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency", + 50000000); + plat->deactivate_delay_us = fdtdec_get_int(blob, node, + "spi-deactivate-delay", 0); + debug("%s: base=%x, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n", + __func__, plat->base, plat->periph_id, plat->frequency, + plat->deactivate_delay_us); + + return 0; +} + +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__); + priv->regs = (struct rockchip_spi *)plat->base; + + priv->last_transaction_us = timer_get_us(); + priv->max_freq = plat->frequency; + priv->periph_id = plat->periph_id; + ret = uclass_get_device(UCLASS_CLK, CLK_GENERAL, &priv->clk_gpll); + if (ret) { + debug("%s: Failed to find CLK_GENERAL: %d\n", __func__, ret); + return ret; + } + + /* + * Use 99 MHz as our clock since it divides nicely into 594 MHz which + * is the assumed speed for CLK_GENERAL. + */ + ret = clk_set_periph_rate(priv->clk_gpll, plat->periph_id, 99000000); + 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); + priv->bits_per_word = 8; + priv->tmode = TMOD_TR; /* Tx & Rx */ + + return 0; +} + +static int rockchip_spi_claim_bus(struct udevice *dev) +{ + struct udevice *bus = dev->parent; + struct rockchip_spi_platdata *plat = dev_get_platdata(bus); + 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); + u8 spi_dfs, spi_tf; + uint ctrlr0; + int ret; + + /* Disable the SPI hardware */ + rkspi_enable_chip(regs, 0); + + switch (priv->bits_per_word) { + case 8: + priv->n_bytes = 1; + spi_dfs = DFS_8BIT; + spi_tf = HALF_WORD_OFF; + break; + case 16: + priv->n_bytes = 2; + spi_dfs = DFS_16BIT; + spi_tf = HALF_WORD_ON; + break; + default: + debug("%s: unsupported bits: %dbits\n", __func__, + priv->bits_per_word); + return -EPROTONOSUPPORT; + } + + rkspi_set_clk(priv, priv->speed_hz); + + /* Operation Mode */ + ctrlr0 = OMOD_MASTER << OMOD_SHIFT; + + /* Data Frame Size */ + ctrlr0 |= spi_dfs & DFS_MASK << 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 |= (spi_tf & HALF_WORD_MASK) << HALF_WORD_TX_SHIFT; + + /* Rxd Sample Delay */ + ctrlr0 |= 0 << RXDSD_SHIFT; + + /* Frame Format */ + ctrlr0 |= FRF_SPI << FRF_SHIFT; + + /* Tx and Rx mode */ + ctrlr0 |= (priv->tmode & TMOD_MASK) << TMOD_SHIFT; + + writel(ctrlr0, ®s->ctrlr0); + + ret = pinctrl_request(plat->pinctrl, priv->periph_id, slave_plat->cs); + if (ret) { + debug("%s: Cannot request pinctrl: %d\n", __func__, ret); + return ret; + } + + return 0; +} + +static int rockchip_spi_release_bus(struct udevice *dev) +{ + 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; + + 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(regs, slave_plat->cs); + + while (len > 0) { + int todo = min(len, 0xffff); + + rkspi_enable_chip(regs, true); + 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--; + } + } + ret = rkspi_wait_till_not_busy(regs); + if (ret) + break; + len -= todo; + } + + /* Deassert CS after transfer */ + if (flags & SPI_XFER_END) + spi_cs_deactivate(regs, 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); + + if (speed > ROCKCHIP_SPI_MAX_RATE) + return -EINVAL; + 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 + */ +}; + +static const struct udevice_id rockchip_spi_ids[] = { + { .compatible = "rockchip,rk3288-spi" }, + { } +}; + +U_BOOT_DRIVER(rockchip_spi) = { + .name = "rockchip_spi", + .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, +}; |