[U-Boot] [PATCH 03/10] dm: spi: add BCM63xx SPI driver

Álvaro Fernández Rojas
2017-06-07T15:35:27Z

Hi Jagan,

El 7/6/17 a las 9:35, Jagan Teki escribió:
> On Fri, May 19, 2017 at 12:59 AM, Álvaro Fernández Rojas
> <noltari@gmail.com> wrote:
>> 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@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@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 <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 */ }
>
> Try to add .data with reg_space of respective controller, this will
> eventually reduce to driver configs and make it CONFIG_BCM63XX and
> reduce unneeded#ifdef.
This implies adding considerable bloat to the driver...
Is it imperative for the driver to be accepted?

>
> thanks!
>

Thanks.