[U-Boot] [PATCH 03/10] dm: spi: add BCM63xx SPI driver
Álvaro Fernández Rojas
noltari at gmail.com
Thu May 18 19:29:41 UTC 2017
This driver is a simplified version of linux/drivers/spi/spi-bcm63xx.c
Instead of supporting both HW revisions of the controller in a single build,
support has been split by the selected config to save space.
Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
---
drivers/spi/Kconfig | 23 +++
drivers/spi/Makefile | 1 +
drivers/spi/bcm63xx_spi.c | 404 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 428 insertions(+)
create mode 100644 drivers/spi/bcm63xx_spi.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index a00d401..d458dd7 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -43,6 +43,29 @@ config ATMEL_SPI
many AT32 (AVR32) and AT91 (ARM) chips. This driver can be
used to access the SPI Flash, such as AT25DF321.
+choice
+ prompt "BCM63xx SPI driver"
+ depends on ARCH_BMIPS
+ optional
+
+config BCM6338_SPI
+ bool "BCM6338 SPI driver"
+ select SPI_MAX_WRITE_CMD_BYTES
+ help
+ Enable the BCM6338 SPI driver. This driver can be used to
+ access the SPI NOR flash on platforms embedding this Broadcom
+ SPI core.
+
+config BCM6358_SPI
+ bool "BCM6358 SPI driver"
+ select SPI_MAX_WRITE_CMD_BYTES
+ help
+ Enable the BCM6358 SPI driver. This driver can be used to
+ access the SPI NOR flash on platforms embedding this Broadcom
+ SPI core.
+
+endchoice
+
config CADENCE_QSPI
bool "Cadence QSPI driver"
help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index c090562..c9ba648 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_ALTERA_SPI) += altera_spi.o
obj-$(CONFIG_ATH79_SPI) += ath79_spi.o
obj-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o
obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o
+obj-$(CONFIG_BCM6338_SPI)$(CONFIG_BCM6358_SPI) += bcm63xx_spi.o
obj-$(CONFIG_CADENCE_QSPI) += cadence_qspi.o cadence_qspi_apb.o
obj-$(CONFIG_CF_SPI) += cf_spi.o
obj-$(CONFIG_DAVINCI_SPI) += davinci_spi.o
diff --git a/drivers/spi/bcm63xx_spi.c b/drivers/spi/bcm63xx_spi.c
new file mode 100644
index 0000000..6e64607
--- /dev/null
+++ b/drivers/spi/bcm63xx_spi.c
@@ -0,0 +1,404 @@
+/*
+ * Copyright (C) 2017 Álvaro Fernández Rojas <noltari at gmail.com>
+ *
+ * Derived from linux/drivers/spi/spi-bcm63xx.c:
+ * Copyright (C) 2009-2012 Florian Fainelli <florian at openwrt.org>
+ * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc at efixo.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <spi.h>
+#include <reset.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#if defined(CONFIG_BCM6338_SPI)
+
+# define SPI_DT_ID "brcm,bcm6338-spi"
+
+/* SPI Command register */
+# define SPI_CMD_REG 0x00
+
+/* SPI Interrupt registers */
+# define SPI_IR_STAT_REG 0x02
+# define SPI_IR_MASK_REG 0x04
+
+/* SPI Clock register */
+# define SPI_CLK_REG 0x06
+
+/* SPI Fill register */
+# define SPI_FILL_REG 0x07
+
+/* SPI Control register (8 bit) */
+# define SPI_CTL_REG 0x40
+# define SPI_CTL_BYTES_SHIFT 0
+# define SPI_CTL_BYTES_MASK (0x3f << SPI_CTL_BYTES_SHIFT)
+# define SPI_CTL_TYPE_SHIFT 6
+# define SPI_CTL_TYPE_FD_RW (0 << SPI_CTL_TYPE_SHIFT)
+# define SPI_CTL_TYPE_HD_W (1 << SPI_CTL_TYPE_SHIFT)
+# define SPI_CTL_TYPE_HD_R (2 << SPI_CTL_TYPE_SHIFT)
+
+# define bcm63xx_spi_wctl(v,a) writeb_be(v, a);
+
+/* SPI TX Data registers */
+# define SPI_TX_DATA_REG 0x41
+# define SPI_TX_DATA_SIZE 0x3f
+
+/* SPI RX Data registers */
+# define SPI_RX_DATA_REG 0x80
+# define SPI_RX_DATA_SIZE 0x3f
+
+#elif defined(CONFIG_BCM6358_SPI)
+
+# define SPI_DT_ID "brcm,bcm6358-spi"
+
+/* SPI Control register (16 bit) */
+# define SPI_CTL_REG 0x000
+# define SPI_CTL_BYTES_SHIFT 0
+# define SPI_CTL_BYTES_MASK (0x3ff << SPI_CTL_BYTES_SHIFT)
+# define SPI_CTL_TYPE_SHIFT 14
+# define SPI_CTL_TYPE_FD_RW (0 << SPI_CTL_TYPE_SHIFT)
+# define SPI_CTL_TYPE_HD_W (1 << SPI_CTL_TYPE_SHIFT)
+# define SPI_CTL_TYPE_HD_R (2 << SPI_CTL_TYPE_SHIFT)
+
+# define bcm63xx_spi_wctl(v,a) writew_be(v, a);
+
+/* SPI TX Data registers */
+# define SPI_TX_DATA_REG 0x002
+# define SPI_TX_DATA_SIZE 0x21e
+
+/* SPI RX Data registers */
+# define SPI_RX_DATA_REG 0x400
+# define SPI_RX_DATA_SIZE 0x220
+
+/* SPI Command register */
+# define SPI_CMD_REG 0x700
+
+/* SPI Interrupt registers */
+# define SPI_IR_STAT_REG 0x702
+# define SPI_IR_MASK_REG 0x704
+
+/* SPI Clock register */
+# define SPI_CLK_REG 0x706
+
+/* SPI Fill register */
+# define SPI_FILL_REG 0x707
+
+#endif
+
+/* SPI Command register */
+#define SPI_CMD_OP_SHIFT 0
+#define SPI_CMD_OP_START (0x3 << SPI_CMD_OP_SHIFT)
+#define SPI_CMD_SLAVE_SHIFT 4
+#define SPI_CMD_SLAVE_MASK (0xf << SPI_CMD_SLAVE_SHIFT)
+#define SPI_CMD_PREPEND_SHIFT 8
+#define SPI_CMD_PREPEND_BYTES 0xf
+#define SPI_CMD_3WIRE_SHIFT 12
+#define SPI_CMD_3WIRE_MASK (1 << SPI_CMD_3WIRE_SHIFT)
+
+/* SPI Interrupt registers */
+#define SPI_IR_DONE_SHIFT 0
+#define SPI_IR_DONE_MASK (1 << SPI_IR_DONE_SHIFT)
+#define SPI_IR_RXOVER_SHIFT 1
+#define SPI_IR_RXOVER_MASK (1 << SPI_IR_RXOVER_SHIFT)
+#define SPI_IR_TXUNDER_SHIFT 2
+#define SPI_IR_TXUNDER_MASK (1 << SPI_IR_TXUNDER_SHIFT)
+#define SPI_IR_TXOVER_SHIFT 3
+#define SPI_IR_TXOVER_MASK (1 << SPI_IR_TXOVER_SHIFT)
+#define SPI_IR_RXUNDER_SHIFT 4
+#define SPI_IR_RXUNDER_MASK (1 << SPI_IR_RXUNDER_SHIFT)
+#define SPI_IR_CLEAR_MASK (SPI_IR_DONE_MASK |\
+ SPI_IR_RXOVER_MASK |\
+ SPI_IR_TXUNDER_MASK |\
+ SPI_IR_TXOVER_MASK |\
+ SPI_IR_RXUNDER_MASK)
+
+/* SPI Clock register */
+#define SPI_CLK_SHIFT 0
+#define SPI_CLK_20MHZ (0 << SPI_CLK_SHIFT)
+#define SPI_CLK_0_391MHZ (1 << SPI_CLK_SHIFT)
+#define SPI_CLK_0_781MHZ (2 << SPI_CLK_SHIFT)
+#define SPI_CLK_1_563MHZ (3 << SPI_CLK_SHIFT)
+#define SPI_CLK_3_125MHZ (4 << SPI_CLK_SHIFT)
+#define SPI_CLK_6_250MHZ (5 << SPI_CLK_SHIFT)
+#define SPI_CLK_12_50MHZ (6 << SPI_CLK_SHIFT)
+#define SPI_CLK_25MHZ (7 << SPI_CLK_SHIFT)
+#define SPI_CLK_MASK (7 << SPI_CLK_SHIFT)
+#define SPI_CLK_SSOFF_SHIFT 3
+#define SPI_CLK_SSOFF_2 (2 << SPI_CLK_SSOFF_SHIFT)
+#define SPI_CLK_SSOFF_MASK (7 << SPI_CLK_SSOFF_SHIFT)
+#define SPI_CLK_BSWAP_SHIFT 7
+#define SPI_CLK_BSWAP_MASK (1 << SPI_CLK_BSWAP_SHIFT)
+
+#define SPI_CLK_CNT 8
+static const unsigned bcm63xx_spi_freq_table[SPI_CLK_CNT][2] = {
+ { 25000000, SPI_CLK_25MHZ },
+ { 20000000, SPI_CLK_20MHZ },
+ { 12500000, SPI_CLK_12_50MHZ },
+ { 6250000, SPI_CLK_6_250MHZ },
+ { 3125000, SPI_CLK_3_125MHZ },
+ { 1563000, SPI_CLK_1_563MHZ },
+ { 781000, SPI_CLK_0_781MHZ },
+ { 391000, SPI_CLK_0_391MHZ }
+};
+
+struct bcm63xx_spi_priv {
+ void __iomem *regs;
+ uint8_t num_cs;
+ size_t tx_bytes;
+};
+
+static int bcm63xx_spi_cs_info(struct udevice *bus, uint cs,
+ struct spi_cs_info *info)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
+
+ if (cs >= priv->num_cs) {
+ error("no cs %u\n", cs);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int bcm63xx_spi_set_mode(struct udevice *bus, uint mode)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
+
+ if (mode & SPI_LSB_FIRST)
+ setbits_8(priv->regs + SPI_CLK_REG, SPI_CLK_BSWAP_MASK);
+ else
+ clrbits_8(priv->regs + SPI_CLK_REG, SPI_CLK_BSWAP_MASK);
+
+ return 0;
+}
+
+static int bcm63xx_spi_set_speed(struct udevice *bus, uint speed)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
+ uint8_t clk_cfg;
+ int i;
+
+ /* default to lowest clock configuration */
+ clk_cfg = SPI_CLK_0_391MHZ;
+
+ /* find the closest clock configuration */
+ for (i = 0; i < SPI_CLK_CNT; i++) {
+ if (speed >= bcm63xx_spi_freq_table[i][0]) {
+ clk_cfg = bcm63xx_spi_freq_table[i][1];
+ break;
+ }
+ }
+
+ /* write clock configuration */
+ clrsetbits_8(priv->regs + SPI_CLK_REG,
+ SPI_CLK_SSOFF_MASK | SPI_CLK_MASK,
+ clk_cfg | SPI_CLK_SSOFF_2);
+
+ return 0;
+}
+
+/*
+ * BCM63xx SPI driver doesn't allow keeping CS active between transfers since
+ * they are HW controlled.
+ * However, it provides a mechanism to prepend write transfers prior to read
+ * transfers (with a maximum prepend of 15 bytes), which is usually enough for
+ * SPI-connected flashes since reading requires prepending a write transfer of
+ * 5 bytes.
+ *
+ * This implementation takes advantage of the prepend mechanism and combines
+ * multiple transfers into a single one where possible (single/multiple write
+ * transfer(s) followed by a final read/write transfer).
+ * However, it's not possible to buffer reads, which means that read transfers
+ * should always be done as the final ones.
+ * On the other hand, take into account that combining write transfers into
+ * a single one is just buffering and doesn't require prepend mechanism.
+ */
+static int bcm63xx_spi_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
+ size_t data_bytes = bitlen / 8;
+
+ if (flags & SPI_XFER_BEGIN) {
+ /* clear prepends */
+ priv->tx_bytes = 0;
+
+ /* initialize hardware */
+ writeb_be(0, priv->regs + SPI_IR_MASK_REG);
+ }
+
+ if (din) {
+ /* buffering reads not possible since cs is hw controlled */
+ if (!(flags & SPI_XFER_END)) {
+ error("unable to buffer reads\n");
+ return -EINVAL;
+ }
+
+ /* check rx size */
+ if (data_bytes > SPI_RX_DATA_SIZE) {
+ error("max rx bytes exceeded\n");
+ return -EMSGSIZE;
+ }
+ }
+
+ if (dout) {
+ /* check tx size */
+ if (priv->tx_bytes + data_bytes > SPI_TX_DATA_SIZE) {
+ error("max tx bytes exceeded\n");
+ return -EMSGSIZE;
+ }
+
+ /* copy tx data */
+ memcpy_toio(priv->regs + SPI_TX_DATA_REG + priv->tx_bytes,
+ dout, data_bytes);
+ priv->tx_bytes += data_bytes;
+ }
+
+ if (flags & SPI_XFER_END) {
+ struct dm_spi_slave_platdata *plat =
+ dev_get_parent_platdata(dev);
+ uint16_t val = 0;
+ uint8_t irq;
+
+ /* determine control config */
+ if (dout && !din) {
+ /* buffered write transfers */
+ val |= (priv->tx_bytes << SPI_CTL_BYTES_SHIFT);
+ val |= SPI_CTL_TYPE_HD_W;
+ priv->tx_bytes = 0;
+ } else {
+ if (dout && din && (flags & SPI_XFER_ONCE)) {
+ /* full duplex read/write */
+ val |= (data_bytes << SPI_CTL_BYTES_SHIFT);
+ val |= SPI_CTL_TYPE_FD_RW;
+ priv->tx_bytes = 0;
+ } else {
+ /* prepended write transfer */
+ val |= (data_bytes << SPI_CTL_BYTES_SHIFT);
+ val |= SPI_CTL_TYPE_HD_R;
+ if (priv->tx_bytes > SPI_CMD_PREPEND_BYTES) {
+ error("max prepend bytes exceeded\n");
+ return -EMSGSIZE;
+ }
+ }
+ }
+ bcm63xx_spi_wctl(val, priv->regs + SPI_CTL_REG);
+
+ /* clear interrupts */
+ writeb_be(SPI_IR_CLEAR_MASK, priv->regs + SPI_IR_STAT_REG);
+
+ /* issue the transfer */
+ val = SPI_CMD_OP_START;
+ val |= (plat->cs << SPI_CMD_SLAVE_SHIFT) & SPI_CMD_SLAVE_MASK;
+ val |= (priv->tx_bytes << SPI_CMD_PREPEND_SHIFT);
+ if (plat->mode & SPI_3WIRE)
+ val |= SPI_CMD_3WIRE_MASK;
+ writew_be(val, priv->regs + SPI_CMD_REG);
+
+ /* enable interrupts */
+ writeb_be(SPI_IR_DONE_MASK, priv->regs + SPI_IR_MASK_REG);
+
+ do {
+ /* read interupts */
+ irq = readb_be(priv->regs + SPI_IR_STAT_REG);
+
+ /* transfer completed */
+ if (irq & SPI_IR_DONE_MASK)
+ break;
+ } while (1);
+
+ /* copy rx data */
+ if (din)
+ memcpy_fromio(din, priv->regs + SPI_RX_DATA_REG,
+ data_bytes);
+ }
+
+ return 0;
+}
+
+static const struct dm_spi_ops bcm63xx_spi_ops = {
+ .cs_info = bcm63xx_spi_cs_info,
+ .set_mode = bcm63xx_spi_set_mode,
+ .set_speed = bcm63xx_spi_set_speed,
+ .xfer = bcm63xx_spi_xfer,
+};
+
+static const struct udevice_id bcm63xx_spi_ids[] = {
+ { .compatible = SPI_DT_ID, },
+ { /* sentinel */ }
+};
+
+static int bcm63xx_spi_child_pre_probe(struct udevice *dev)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
+ struct spi_slave *slave = dev_get_parent_priv(dev);
+ struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
+
+ /* check cs */
+ if (plat->cs >= priv->num_cs) {
+ error("no cs %u\n", plat->cs);
+ return -ENODEV;
+ }
+
+ /* max read/write sizes */
+ slave->max_read_size = SPI_RX_DATA_SIZE;
+ slave->max_write_size = SPI_TX_DATA_SIZE;
+
+ return 0;
+}
+
+static int bcm63xx_spi_probe(struct udevice *dev)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(dev);
+ struct reset_ctl rst_ctl;
+ struct clk clk;
+ fdt_addr_t addr;
+ fdt_size_t size;
+ int ret;
+
+ addr = dev_get_addr_size_index(dev, 0, &size);
+ if (addr == FDT_ADDR_T_NONE)
+ return -EINVAL;
+
+ priv->regs = ioremap(addr, size);
+ priv->num_cs = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
+ "num-cs", 8);
+
+ /* enable clock */
+ ret = clk_get_by_index(dev, 0, &clk);
+ if (ret < 0)
+ return ret;
+ clk_enable(&clk);
+ clk_free(&clk);
+
+ /* perform reset */
+ ret = reset_get_by_index(dev, 0, &rst_ctl);
+ if (ret < 0)
+ return ret;
+ reset_deassert(&rst_ctl);
+ reset_free(&rst_ctl);
+
+ /* initialize hardware */
+ writeb_be(0, priv->regs + SPI_IR_MASK_REG);
+
+ /* set fill register */
+ writeb_be(0xff, priv->regs + SPI_FILL_REG);
+
+ return 0;
+}
+
+U_BOOT_DRIVER(bcm63xx_spi) = {
+ .name = "bcm63xx_spi",
+ .id = UCLASS_SPI,
+ .of_match = bcm63xx_spi_ids,
+ .ops = &bcm63xx_spi_ops,
+ .priv_auto_alloc_size = sizeof(struct bcm63xx_spi_priv),
+ .child_pre_probe = bcm63xx_spi_child_pre_probe,
+ .probe = bcm63xx_spi_probe,
+};
--
2.1.4
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