+// 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, <superpeter.cai@gmail.com>.
- *
- * SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <dt-structs.h>
#include <errno.h>
+#include <log.h>
#include <spi.h>
+#include <time.h>
+#include <linux/delay.h>
#include <linux/errno.h>
#include <asm/io.h>
-#include <asm/arch/clock.h>
-#include <asm/arch/periph.h>
+#include <asm/arch-rockchip/clock.h>
+#include <asm/arch-rockchip/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
+/*
+ * ctrlr1 is 16-bits, so we should support lengths of 0xffff + 1. However,
+ * the controller seems to hang when given 0x10000, so stick with this for now.
+ */
+#define ROCKCHIP_SPI_MAX_TRANLEN 0xffff
+
+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;
unsigned int max_freq;
unsigned int mode;
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 last_speed_hz;
- unsigned int tmode;
uint input_rate;
};
static void rkspi_set_clk(struct rockchip_spi_priv *priv, uint speed)
{
- uint clk_div;
+ /*
+ * 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;
- 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);
+ clrsetbits_le32(&priv->regs->baudr, 0xffff, clk_div);
priv->last_speed_hz = speed;
}
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)
- udelay(plat->deactivate_delay_us - delay_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);
#if !CONFIG_IS_ENABLED(OF_PLATDATA)
struct rockchip_spi_platdata *plat = dev_get_platdata(bus);
struct rockchip_spi_priv *priv = dev_get_priv(bus);
- const void *blob = gd->fdt_blob;
- int node = dev_of_offset(bus);
int ret;
- plat->base = dev_get_addr(bus);
+ plat->base = dev_read_addr(bus);
ret = clk_get_by_index(bus, 0, &priv->clk);
if (ret < 0) {
return 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);
- plat->activate_delay_us = fdtdec_get_int(blob, node,
- "spi-activate-delay", 0);
+ 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);
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);
priv->last_transaction_us = timer_get_us();
priv->max_freq = plat->frequency;
- /*
- * Use 99 MHz as our clock since it divides nicely into 594 MHz which
- * is the assumed speed for CLK_GENERAL.
- */
- ret = clk_set_rate(&priv->clk, 99000000);
+ /* 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);
- priv->bits_per_word = 8;
- priv->tmode = TMOD_TR; /* Tx & Rx */
return 0;
}
struct udevice *bus = dev->parent;
struct rockchip_spi_priv *priv = dev_get_priv(bus);
struct rockchip_spi *regs = priv->regs;
- u8 spi_dfs, spi_tf;
uint ctrlr0;
/* 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_enable_chip(regs, false);
if (priv->speed_hz != priv->last_speed_hz)
rkspi_set_clk(priv, priv->speed_hz);
ctrlr0 = OMOD_MASTER << OMOD_SHIFT;
/* Data Frame Size */
- ctrlr0 |= spi_dfs << DFS_SHIFT;
+ ctrlr0 |= DFS_8BIT << DFS_SHIFT;
/* set SPI mode 0..3 */
if (priv->mode & SPI_CPOL)
ctrlr0 |= FBM_MSB << FBM_SHIFT;
/* Byte and Halfword Transform */
- ctrlr0 |= spi_tf << HALF_WORD_TX_SHIFT;
+ ctrlr0 |= HALF_WORD_OFF << HALF_WORD_TX_SHIFT;
/* Rxd Sample Delay */
ctrlr0 |= 0 << RXDSD_SHIFT;
ctrlr0 |= FRF_SPI << FRF_SHIFT;
/* Tx and Rx mode */
- ctrlr0 |= (priv->tmode & TMOD_MASK) << TMOD_SHIFT;
+ ctrlr0 |= TMOD_TR << TMOD_SHIFT;
writel(ctrlr0, ®s->ctrlr0);
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;
+ u8 *in = (u8 *)(*din);
+ u32 max_chunk_size = SPI_FIFO_DEPTH;
+
+ if (!frames)
+ 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 = ROCKCHIP_SPI_MAX_TRANLEN;
+
+ // 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--) {
+ u16 val = readw(regs->rxdr);
+ *in++ = val & 0xff;
+ *in++ = val >> 8;
+ }
+ } 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)
{
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);
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, 0xffff);
+ int todo = min(len, ROCKCHIP_SPI_MAX_TRANLEN);
rkspi_enable_chip(regs, false);
writel(todo - 1, ®s->ctrlr1);
toread--;
}
}
- ret = rkspi_wait_till_not_busy(regs);
- if (ret)
- break;
+
+ /*
+ * 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;
}
{
struct rockchip_spi_priv *priv = dev_get_priv(bus);
- if (speed > ROCKCHIP_SPI_MAX_RATE)
- return -EINVAL;
+ /* Clamp to the maximum frequency specified in the DTS */
if (speed > priv->max_freq)
speed = priv->max_freq;
+
priv->speed_hz = speed;
return 0;
*/
};
+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 },
{ }
};
projects / oweals / u-boot.git / blobdiff