dm: spi: add BCM63xx SPI driver
authorÁlvaro Fernández Rojas <noltari@gmail.com>
Tue, 23 Jan 2018 16:14:58 +0000 (17:14 +0100)
committerJagan Teki <jagan@amarulasolutions.com>
Wed, 24 Jan 2018 06:33:43 +0000 (12:03 +0530)
This driver is a simplified version of linux/drivers/spi/spi-bcm63xx.c

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
drivers/spi/Kconfig
drivers/spi/Makefile
drivers/spi/bcm63xx_spi.c [new file with mode: 0644]

index 494639fb0196faf0552a529b593c5b253f059bc5..ebc71c2e42b964b46d3c3a652a1efe71deb596de 100644 (file)
@@ -40,6 +40,14 @@ config ATMEL_SPI
          many AT91 (ARM) chips. This driver can be used to access
          the SPI Flash, such as AT25DF321.
 
+config BCM63XX_SPI
+       bool "BCM6348 SPI driver"
+       depends on ARCH_BMIPS
+       help
+         Enable the BCM6348/BCM6358 SPI driver. This driver can be used to
+         access the SPI NOR flash on platforms embedding these Broadcom
+         SPI cores.
+
 config CADENCE_QSPI
        bool "Cadence QSPI driver"
        help
index e3184db67f516bda97caf74bab2754cca4e8f424..5770b3f7ccce974bdbd2475092d1f88df42ee35b 100644 (file)
@@ -18,6 +18,7 @@ endif
 obj-$(CONFIG_ALTERA_SPI) += altera_spi.o
 obj-$(CONFIG_ATH79_SPI) += ath79_spi.o
 obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o
+obj-$(CONFIG_BCM63XX_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 (file)
index 0000000..f0df687
--- /dev/null
@@ -0,0 +1,433 @@
+/*
+ * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
+ *
+ * Derived from linux/drivers/spi/spi-bcm63xx.c:
+ *     Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
+ *     Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <spi.h>
+#include <reset.h>
+#include <wait_bit.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* BCM6348 SPI core */
+#define SPI_6348_CLK                   0x06
+#define SPI_6348_CMD                   0x00
+#define SPI_6348_CTL                   0x40
+#define SPI_6348_CTL_SHIFT             6
+#define SPI_6348_FILL                  0x07
+#define SPI_6348_IR_MASK               0x04
+#define SPI_6348_IR_STAT               0x02
+#define SPI_6348_RX                    0x80
+#define SPI_6348_RX_SIZE               0x3f
+#define SPI_6348_TX                    0x41
+#define SPI_6348_TX_SIZE               0x3f
+
+/* BCM6358 SPI core */
+#define SPI_6358_CLK                   0x706
+#define SPI_6358_CMD                   0x700
+#define SPI_6358_CTL                   0x000
+#define SPI_6358_CTL_SHIFT             14
+#define SPI_6358_FILL                  0x707
+#define SPI_6358_IR_MASK               0x702
+#define SPI_6358_IR_STAT               0x704
+#define SPI_6358_RX                    0x400
+#define SPI_6358_RX_SIZE               0x220
+#define SPI_6358_TX                    0x002
+#define SPI_6358_TX_SIZE               0x21e
+
+/* 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)
+
+/* 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 Control register */
+#define SPI_CTL_TYPE_FD_RW     0
+#define SPI_CTL_TYPE_HD_W      1
+#define SPI_CTL_TYPE_HD_R      2
+
+/* 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)
+
+enum bcm63xx_regs_spi {
+       SPI_CLK,
+       SPI_CMD,
+       SPI_CTL,
+       SPI_CTL_SHIFT,
+       SPI_FILL,
+       SPI_IR_MASK,
+       SPI_IR_STAT,
+       SPI_RX,
+       SPI_RX_SIZE,
+       SPI_TX,
+       SPI_TX_SIZE,
+};
+
+struct bcm63xx_spi_priv {
+       const unsigned long *regs;
+       void __iomem *base;
+       size_t tx_bytes;
+       uint8_t num_cs;
+};
+
+#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 }
+};
+
+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) {
+               printf("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);
+       const unsigned long *regs = priv->regs;
+
+       if (mode & SPI_LSB_FIRST)
+               setbits_8(priv->base + regs[SPI_CLK], SPI_CLK_BSWAP_MASK);
+       else
+               clrbits_8(priv->base + regs[SPI_CLK], 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);
+       const unsigned long *regs = priv->regs;
+       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->base + regs[SPI_CLK],
+                    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);
+       const unsigned long *regs = priv->regs;
+       size_t data_bytes = bitlen / 8;
+
+       if (flags & SPI_XFER_BEGIN) {
+               /* clear prepends */
+               priv->tx_bytes = 0;
+
+               /* initialize hardware */
+               writeb_be(0, priv->base + regs[SPI_IR_MASK]);
+       }
+
+       if (din) {
+               /* buffering reads not possible since cs is hw controlled */
+               if (!(flags & SPI_XFER_END)) {
+                       printf("unable to buffer reads\n");
+                       return -EINVAL;
+               }
+
+               /* check rx size */
+                if (data_bytes > regs[SPI_RX_SIZE]) {
+                       printf("max rx bytes exceeded\n");
+                       return -EMSGSIZE;
+               }
+       }
+
+       if (dout) {
+               /* check tx size */
+               if (priv->tx_bytes + data_bytes > regs[SPI_TX_SIZE]) {
+                       printf("max tx bytes exceeded\n");
+                       return -EMSGSIZE;
+               }
+
+               /* copy tx data */
+               memcpy_toio(priv->base + regs[SPI_TX] + 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, cmd;
+               int ret;
+
+               /* determine control config */
+               if (dout && !din) {
+                       /* buffered write transfers */
+                       val = priv->tx_bytes;
+                       val |= (SPI_CTL_TYPE_HD_W << regs[SPI_CTL_SHIFT]);
+                       priv->tx_bytes = 0;
+               } else {
+                       if (dout && din && (flags & SPI_XFER_ONCE)) {
+                               /* full duplex read/write */
+                               val = data_bytes;
+                               val |= (SPI_CTL_TYPE_FD_RW <<
+                                       regs[SPI_CTL_SHIFT]);
+                               priv->tx_bytes = 0;
+                       } else {
+                               /* prepended write transfer */
+                               val = data_bytes;
+                               val |= (SPI_CTL_TYPE_HD_R <<
+                                       regs[SPI_CTL_SHIFT]);
+                               if (priv->tx_bytes > SPI_CMD_PREPEND_BYTES) {
+                                       printf("max prepend bytes exceeded\n");
+                                       return -EMSGSIZE;
+                               }
+                       }
+               }
+
+               if (regs[SPI_CTL_SHIFT] >= 8)
+                       writew_be(val, priv->base + regs[SPI_CTL]);
+               else
+                       writeb_be(val, priv->base + regs[SPI_CTL]);
+
+               /* clear interrupts */
+               writeb_be(SPI_IR_CLEAR_MASK, priv->base + regs[SPI_IR_STAT]);
+
+               /* issue the transfer */
+               cmd = SPI_CMD_OP_START;
+               cmd |= (plat->cs << SPI_CMD_SLAVE_SHIFT) & SPI_CMD_SLAVE_MASK;
+               cmd |= (priv->tx_bytes << SPI_CMD_PREPEND_SHIFT);
+               if (plat->mode & SPI_3WIRE)
+                       cmd |= SPI_CMD_3WIRE_MASK;
+               writew_be(cmd, priv->base + regs[SPI_CMD]);
+
+               /* enable interrupts */
+               writeb_be(SPI_IR_DONE_MASK, priv->base + regs[SPI_IR_MASK]);
+
+               ret = wait_for_bit_8(priv->base + regs[SPI_IR_STAT],
+                                    SPI_IR_DONE_MASK, true, 1000, false);
+               if (ret) {
+                       printf("interrupt timeout\n");
+                       return ret;
+               }
+
+               /* copy rx data */
+               if (din)
+                       memcpy_fromio(din, priv->base + regs[SPI_RX],
+                                     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 unsigned long bcm6348_spi_regs[] = {
+       [SPI_CLK] = SPI_6348_CLK,
+       [SPI_CMD] = SPI_6348_CMD,
+       [SPI_CTL] = SPI_6348_CTL,
+       [SPI_CTL_SHIFT] = SPI_6348_CTL_SHIFT,
+       [SPI_FILL] = SPI_6348_FILL,
+       [SPI_IR_MASK] = SPI_6348_IR_MASK,
+       [SPI_IR_STAT] = SPI_6348_IR_STAT,
+       [SPI_RX] = SPI_6348_RX,
+       [SPI_RX_SIZE] = SPI_6348_RX_SIZE,
+       [SPI_TX] = SPI_6348_TX,
+       [SPI_TX_SIZE] = SPI_6348_TX_SIZE,
+};
+
+static const unsigned long bcm6358_spi_regs[] = {
+       [SPI_CLK] = SPI_6358_CLK,
+       [SPI_CMD] = SPI_6358_CMD,
+       [SPI_CTL] = SPI_6358_CTL,
+       [SPI_CTL_SHIFT] = SPI_6358_CTL_SHIFT,
+       [SPI_FILL] = SPI_6358_FILL,
+       [SPI_IR_MASK] = SPI_6358_IR_MASK,
+       [SPI_IR_STAT] = SPI_6358_IR_STAT,
+       [SPI_RX] = SPI_6358_RX,
+       [SPI_RX_SIZE] = SPI_6358_RX_SIZE,
+       [SPI_TX] = SPI_6358_TX,
+       [SPI_TX_SIZE] = SPI_6358_TX_SIZE,
+};
+
+static const struct udevice_id bcm63xx_spi_ids[] = {
+       {
+               .compatible = "brcm,bcm6348-spi",
+               .data = (ulong)&bcm6348_spi_regs,
+       }, {
+               .compatible = "brcm,bcm6358-spi",
+               .data = (ulong)&bcm6358_spi_regs,
+       }, { /* sentinel */ }
+};
+
+static int bcm63xx_spi_child_pre_probe(struct udevice *dev)
+{
+       struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
+       const unsigned long *regs = priv->regs;
+       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) {
+               printf("no cs %u\n", plat->cs);
+               return -ENODEV;
+       }
+
+       /* max read/write sizes */
+       slave->max_read_size = regs[SPI_RX_SIZE];
+       slave->max_write_size = regs[SPI_TX_SIZE];
+
+       return 0;
+}
+
+static int bcm63xx_spi_probe(struct udevice *dev)
+{
+       struct bcm63xx_spi_priv *priv = dev_get_priv(dev);
+       const unsigned long *regs =
+               (const unsigned long *)dev_get_driver_data(dev);
+       struct reset_ctl rst_ctl;
+       struct clk clk;
+       fdt_addr_t addr;
+       fdt_size_t size;
+       int ret;
+
+       addr = devfdt_get_addr_size_index(dev, 0, &size);
+       if (addr == FDT_ADDR_T_NONE)
+               return -EINVAL;
+
+       priv->regs = regs;
+       priv->base = 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;
+
+       ret = clk_enable(&clk);
+       if (ret < 0)
+               return ret;
+
+       ret = clk_free(&clk);
+       if (ret < 0)
+               return ret;
+
+       /* perform reset */
+       ret = reset_get_by_index(dev, 0, &rst_ctl);
+       if (ret < 0)
+               return ret;
+
+       ret = reset_deassert(&rst_ctl);
+       if (ret < 0)
+               return ret;
+
+       ret = reset_free(&rst_ctl);
+       if (ret < 0)
+               return ret;
+
+       /* initialize hardware */
+       writeb_be(0, priv->base + regs[SPI_IR_MASK]);
+
+       /* set fill register */
+       writeb_be(0xff, priv->base + regs[SPI_FILL]);
+
+       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,
+};