Re: [PATCH v2 8/9] spi: bcmbca-hsspi: Add driver for newer HSSPI controller

Hi Jagan,

On 06/01/2023 10:54 PM, Jagan Teki wrote:

On Wed, May 3, 2023 at 12:29 AM William Zhang william.zhang@broadcom.com wrote:

...

The newer BCMBCA SoCs such as BCM6756, BCM4912 and BCM6855 include an updated SPI controller that add the capability to allow the driver to control chip select explicitly. Driver can control and keep cs low between the transfers natively. Hence the dummy cs workaround or prepend mode found in the bcm63xx-hsspi driver are no longer needed and this new driver is much cleaner.

Port from linux patch: Link: https://lore.kernel.org/r/20230209200246.141520-15-william.zhang@broadcom.co...

Signed-off-by: William Zhang william.zhang@broadcom.com

Changes in v2: None

arch/arm/mach-bcmbca/Kconfig | 15 ++

Exclude this from spi driver patch. Driver has to be a separate patch.

Sure

...

drivers/spi/Kconfig | 9 + drivers/spi/Makefile | 1 + drivers/spi/bcmbca_hsspi.c | 414 +++++++++++++++++++++++++++++++++++ 4 files changed, 439 insertions(+) create mode 100644 drivers/spi/bcmbca_hsspi.c

diff --git a/arch/arm/mach-bcmbca/Kconfig b/arch/arm/mach-bcmbca/Kconfig index 6441ed5929d2..60b36c4bb0f6 100644 --- a/arch/arm/mach-bcmbca/Kconfig +++ b/arch/arm/mach-bcmbca/Kconfig @@ -27,6 +27,7 @@ config BCM4912 select SYS_ARCH_TIMER select DM_SERIAL select PL01X_SERIAL

•   select BCMBCA_HSSPI
  
  

  config BCM63138 bool "Support for Broadcom 63138 Family"

@@ -75,6 +76,7 @@ config BCM6756 select CPU_V7A select DM_SERIAL select PL01X_SERIAL

•   select BCMBCA_HSSPI
  
  

  config BCM6813 bool "Support for Broadcom 6813 Family"

@@ -82,6 +84,7 @@ config BCM6813 select SYS_ARCH_TIMER select DM_SERIAL select PL01X_SERIAL

•   select BCMBCA_HSSPI
  
  

  config BCM6846 bool "Support for Broadcom 6846 Family"

@@ -97,6 +100,7 @@ config BCM6855 select CPU_V7A select DM_SERIAL select PL01X_SERIAL

•   select BCMBCA_HSSPI
     help
       Broadcom BCM6855 is a triple core Cortex A7 based xPON Gateway
       SoC. This SoC family includes BCM6855x, BCM68252 and BCM6753.
  

@@ -131,6 +135,17 @@ config BCM6878 select PL01X_SERIAL select BCM63XX_HSSPI

+config HAVE_SPI_CS_CTRL

•   bool "SoC supports SPI chip select control"
  

•   default y if BCM4912
  

•   default y if BCM6756
  

•   default y if BCM6855
  

•   default y if BCM6813
  

Use ||

Will update

...

•   default n
  

•   help
  

•     Enable this option if SoC supports SPI chip select control explicitly
  

•     through software.
  

• source "arch/arm/mach-bcmbca/bcm47622/Kconfig" source "arch/arm/mach-bcmbca/bcm4908/Kconfig" source "arch/arm/mach-bcmbca/bcm4912/Kconfig"

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 47a261f1e1b8..6b26915f9bb2 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -107,6 +107,15 @@ config BCM63XX_HSSPI access the SPI NOR flash on platforms embedding this Broadcom SPI core.

+config BCMBCA_HSSPI

•   bool "BCMBCA HSSPI driver"
  

•   depends on ARCH_BCMBCA && HAVE_SPI_CS_CTRL
  

•   help
  

•     This enables support for the High Speed SPI controller present on
  

•     newer Broadcom BCMBCA SoCs. These SoCs include an updated SPI controller
  

•     that adds the capability to allow the driver to control chip select
  

•     explicitly.
  

• config BCM63XX_SPI bool "BCM6348 SPI driver" depends on ARCH_BMIPS

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 95dba9ac4559..c27b3327c337 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_ATH79_SPI) += ath79_spi.o obj-$(CONFIG_ATMEL_QSPI) += atmel-quadspi.o obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o obj-$(CONFIG_BCM63XX_HSSPI) += bcm63xx_hsspi.o +obj-$(CONFIG_BCMBCA_HSSPI) += bcmbca_hsspi.o obj-$(CONFIG_BCM63XX_SPI) += bcm63xx_spi.o obj-$(CONFIG_BCMSTB_SPI) += bcmstb_spi.o obj-$(CONFIG_CF_SPI) += cf_spi.o diff --git a/drivers/spi/bcmbca_hsspi.c b/drivers/spi/bcmbca_hsspi.c new file mode 100644 index 000000000000..fbe315a7d45d --- /dev/null +++ b/drivers/spi/bcmbca_hsspi.c @@ -0,0 +1,414 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • Copyright (C) 2017 Álvaro Fernández Rojas noltari@gmail.com
• • Derived from linux/drivers/spi/spi-bcm63xx-hsspi.c:

• • Copyright (C) 2000-2010 Broadcom Corporation
    

• • Copyright (C) 2012-2013 Jonas Gorski <jogo@openwrt.org>
    

• • Copyright (C) 2021 Broadcom Ltd
    

• */

+#include <common.h> +#include <asm/io.h> +#include <clk.h> +#include <spi.h> +#include <reset.h> +#include <wait_bit.h> +#include <dm.h> +#include <dm/device_compat.h>

+#define HSSPI_PP 0

+#define SPI_MAX_SYNC_CLOCK 30000000

What is this clock? spi-max-frequency ? if yes pick it from DT.

Not spi-max-frequency. This is the controller internal setting that determines if controller works in sync or async mode when clock is below or above this frequency.

...

+/* SPI Control register */ +#define SPI_CTL_REG 0x000 +#define SPI_CTL_CS_POL_SHIFT 0 +#define SPI_CTL_CS_POL_MASK (0xff << SPI_CTL_CS_POL_SHIFT) +#define SPI_CTL_CLK_GATE_SHIFT 16 +#define SPI_CTL_CLK_GATE_MASK BIT(SPI_CTL_CLK_GATE_SHIFT) +#define SPI_CTL_CLK_POL_SHIFT 17 +#define SPI_CTL_CLK_POL_MASK BIT(SPI_CTL_CLK_POL_SHIFT)

+/* SPI Interrupts registers */ +#define SPI_IR_STAT_REG 0x008 +#define SPI_IR_ST_MASK_REG 0x00c +#define SPI_IR_MASK_REG 0x010

+#define SPI_IR_CLEAR_ALL 0xff001f1f

+/* SPI Ping-Pong Command registers */ +#define SPI_CMD_REG (0x080 + (0x40 * (HSSPI_PP)) + 0x00) +#define SPI_CMD_OP_SHIFT 0 +#define SPI_CMD_OP_START BIT(SPI_CMD_OP_SHIFT) +#define SPI_CMD_PFL_SHIFT 8 +#define SPI_CMD_PFL_MASK (0x7 << SPI_CMD_PFL_SHIFT) +#define SPI_CMD_SLAVE_SHIFT 12 +#define SPI_CMD_SLAVE_MASK (0x7 << SPI_CMD_SLAVE_SHIFT)

+/* SPI Ping-Pong Status registers */ +#define SPI_STAT_REG (0x080 + (0x40 * (HSSPI_PP)) + 0x04) +#define SPI_STAT_SRCBUSY_SHIFT 1 +#define SPI_STAT_SRCBUSY_MASK BIT(SPI_STAT_SRCBUSY_SHIFT)

+/* SPI Profile Clock registers */ +#define SPI_PFL_CLK_REG(x) (0x100 + (0x20 * (x)) + 0x00) +#define SPI_PFL_CLK_FREQ_SHIFT 0 +#define SPI_PFL_CLK_FREQ_MASK (0x3fff << SPI_PFL_CLK_FREQ_SHIFT) +#define SPI_PFL_CLK_RSTLOOP_SHIFT 15 +#define SPI_PFL_CLK_RSTLOOP_MASK BIT(SPI_PFL_CLK_RSTLOOP_SHIFT)

+/* SPI Profile Signal registers */ +#define SPI_PFL_SIG_REG(x) (0x100 + (0x20 * (x)) + 0x04) +#define SPI_PFL_SIG_LATCHRIS_SHIFT 12 +#define SPI_PFL_SIG_LATCHRIS_MASK BIT(SPI_PFL_SIG_LATCHRIS_SHIFT) +#define SPI_PFL_SIG_LAUNCHRIS_SHIFT 13 +#define SPI_PFL_SIG_LAUNCHRIS_MASK BIT(SPI_PFL_SIG_LAUNCHRIS_SHIFT) +#define SPI_PFL_SIG_ASYNCIN_SHIFT 16 +#define SPI_PFL_SIG_ASYNCIN_MASK BIT(SPI_PFL_SIG_ASYNCIN_SHIFT)

+/* SPI Profile Mode registers */ +#define SPI_PFL_MODE_REG(x) (0x100 + (0x20 * (x)) + 0x08) +#define SPI_PFL_MODE_FILL_SHIFT 0 +#define SPI_PFL_MODE_FILL_MASK (0xff << SPI_PFL_MODE_FILL_SHIFT) +#define SPI_PFL_MODE_MDRDSZ_SHIFT 16 +#define SPI_PFL_MODE_MDRDSZ_MASK BIT(SPI_PFL_MODE_MDRDSZ_SHIFT) +#define SPI_PFL_MODE_MDWRSZ_SHIFT 18 +#define SPI_PFL_MODE_MDWRSZ_MASK BIT(SPI_PFL_MODE_MDWRSZ_SHIFT) +#define SPI_PFL_MODE_3WIRE_SHIFT 20 +#define SPI_PFL_MODE_3WIRE_MASK BIT(SPI_PFL_MODE_3WIRE_SHIFT)

+/* SPI Ping-Pong FIFO registers */ +#define HSSPI_FIFO_SIZE 0x200 +#define HSSPI_FIFO_BASE (0x200 + \

•                                    (HSSPI_FIFO_SIZE * HSSPI_PP))
  

+/* SPI Ping-Pong FIFO OP register */ +#define HSSPI_FIFO_OP_SIZE 0x2 +#define HSSPI_FIFO_OP_REG (HSSPI_FIFO_BASE + 0x00) +#define HSSPI_FIFO_OP_BYTES_SHIFT 0 +#define HSSPI_FIFO_OP_BYTES_MASK (0x3ff << HSSPI_FIFO_OP_BYTES_SHIFT) +#define HSSPI_FIFO_OP_MBIT_SHIFT 11 +#define HSSPI_FIFO_OP_MBIT_MASK BIT(HSSPI_FIFO_OP_MBIT_SHIFT) +#define HSSPI_FIFO_OP_CODE_SHIFT 13 +#define HSSPI_FIFO_OP_READ_WRITE (1 << HSSPI_FIFO_OP_CODE_SHIFT) +#define HSSPI_FIFO_OP_CODE_W (2 << HSSPI_FIFO_OP_CODE_SHIFT) +#define HSSPI_FIFO_OP_CODE_R (3 << HSSPI_FIFO_OP_CODE_SHIFT)

+#define HSSPI_MAX_DATA_SIZE (HSSPI_FIFO_SIZE - HSSPI_FIFO_OP_SIZE)

+#define SPIM_CTRL_CS_OVERRIDE_SEL_SHIFT 0 +#define SPIM_CTRL_CS_OVERRIDE_SEL_MASK 0xff +#define SPIM_CTRL_CS_OVERRIDE_VAL_SHIFT 8 +#define SPIM_CTRL_CS_OVERRIDE_VAL_MASK 0xff

+struct bcmbca_hsspi_priv {

•   void __iomem *regs;
  

•   void __iomem *spim_ctrl;
  

•   u32 clk_rate;
  

•   u8 num_cs;
  

•   u8 cs_pols;
  

•   u32 speed;
  

+};

+static int bcmbca_hsspi_cs_info(struct udevice *bus, uint cs,

•                           struct spi_cs_info *info)
  

+{

•   struct bcmbca_hsspi_priv *priv = dev_get_priv(bus);
  

•   if (cs >= priv->num_cs) {
  

•           dev_err(bus, "no cs %u\n", cs);
  

•           return -EINVAL;
  

•   }
  

•   return 0;
  

+}

+static int bcmbca_hsspi_set_mode(struct udevice *bus, uint mode) +{

•   struct bcmbca_hsspi_priv *priv = dev_get_priv(bus);
  

•   /* clock polarity */
  

•   if (mode & SPI_CPOL)
  

•           setbits_32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
  

•   else
  

•           clrbits_32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
  

•   return 0;
  

+}

+static int bcmbca_hsspi_set_speed(struct udevice *bus, uint speed) +{

•   struct bcmbca_hsspi_priv *priv = dev_get_priv(bus);
  

•   priv->speed = speed;
  

•   return 0;
  

+}

+static void bcmbca_hsspi_setup_clock(struct bcmbca_hsspi_priv *priv,

•                                struct dm_spi_slave_plat *plat)
  

+{

•   u32 clr, set;
  

•   /* profile clock */
  

•   set = DIV_ROUND_UP(priv->clk_rate, priv->speed);
  

•   set = DIV_ROUND_UP(2048, set);
  

•   set &= SPI_PFL_CLK_FREQ_MASK;
  

•   set |= SPI_PFL_CLK_RSTLOOP_MASK;
  

•   writel(set, priv->regs + SPI_PFL_CLK_REG(plat->cs));
  

•   /* profile signal */
  

•   set = 0;
  

•   clr = SPI_PFL_SIG_LAUNCHRIS_MASK |
  

•         SPI_PFL_SIG_LATCHRIS_MASK |
  

•         SPI_PFL_SIG_ASYNCIN_MASK;
  

•   /* latch/launch config */
  

•   if (plat->mode & SPI_CPHA)
  

•           set |= SPI_PFL_SIG_LAUNCHRIS_MASK;
  

•   else
  

•           set |= SPI_PFL_SIG_LATCHRIS_MASK;
  

•   /* async clk */
  

•   if (priv->speed > SPI_MAX_SYNC_CLOCK)
  

•           set |= SPI_PFL_SIG_ASYNCIN_MASK;
  

•   clrsetbits_32(priv->regs + SPI_PFL_SIG_REG(plat->cs), clr, set);
  

I think this won't change every time cs changes, isn't it? if so mode code has to move set_mode and the speed code has to move set_speed.

The controller setting will change if different spi slave select has different settings. The set_mode and set_speed code in this driver do take care some of the settings but these settings need to be applied at the beginning of the transfer. This is same as the original bcm63xx driver.

...

•   /* global control */
  

•   set = 0;
  

•   clr = 0;
  

•   if (priv->cs_pols & BIT(plat->cs))
  

•           set |= BIT(plat->cs);
  

•   else
  

•           clr |= BIT(plat->cs);
  

•   clrsetbits_32(priv->regs + SPI_CTL_REG, clr, set);
  

+}

+static void bcmbca_hsspi_activate_cs(struct bcmbca_hsspi_priv *priv,

•                                struct dm_spi_slave_plat *plat)
  

+{

•   u32 val;
  

•   /* set the override bit */
  

•   val = readl(priv->spim_ctrl);
  

•   val |= BIT(plat->cs + SPIM_CTRL_CS_OVERRIDE_SEL_SHIFT);
  

•   writel(val, priv->spim_ctrl);
  

+}

+static void bcmbca_hsspi_deactivate_cs(struct bcmbca_hsspi_priv *priv,

•                                  struct dm_spi_slave_plat *plat)
  

+{

•   u32 val;
  

•   /* clear the cs override bit */
  

•   val = readl(priv->spim_ctrl);
  

•   val &= ~BIT(plat->cs + SPIM_CTRL_CS_OVERRIDE_SEL_SHIFT);
  

•   writel(val, priv->spim_ctrl);
  

+}

+static int bcmbca_hsspi_xfer(struct udevice *dev, unsigned int bitlen,

•                        const void *dout, void *din, unsigned long flags)
  

+{

•   struct bcmbca_hsspi_priv *priv = dev_get_priv(dev->parent);
  

•   struct dm_spi_slave_plat *plat = dev_get_parent_plat(dev);
  

•   size_t data_bytes = bitlen / 8;
  

•   size_t step_size = HSSPI_FIFO_SIZE;
  

•   u16 opcode = 0;
  

•   u32 val = SPI_PFL_MODE_FILL_MASK;
  

•   const u8 *tx = dout;
  

•   u8 *rx = din;
  

•   u32 cs_act = 0;
  

•   if (flags & SPI_XFER_BEGIN)
  

•           bcmbca_hsspi_setup_clock(priv, plat);
  

•   /* fifo operation */
  

•   if (tx && rx)
  

•           opcode = HSSPI_FIFO_OP_READ_WRITE;
  

•   else if (rx)
  

•           opcode = HSSPI_FIFO_OP_CODE_R;
  

•   else if (tx)
  

•           opcode = HSSPI_FIFO_OP_CODE_W;
  

•   if (opcode != HSSPI_FIFO_OP_CODE_R)
  

•           step_size -= HSSPI_FIFO_OP_SIZE;
  

•   /* dual mode */
  

•   if ((opcode == HSSPI_FIFO_OP_CODE_R && (plat->mode & SPI_RX_DUAL)) ||
  

•       (opcode == HSSPI_FIFO_OP_CODE_W && (plat->mode & SPI_TX_DUAL))) {
  

•           opcode |= HSSPI_FIFO_OP_MBIT_MASK;
  

•           /* profile mode */
  

•           if (plat->mode & SPI_RX_DUAL)
  

•                   val |= SPI_PFL_MODE_MDRDSZ_MASK;
  

•           if (plat->mode & SPI_TX_DUAL)
  

•                   val |= SPI_PFL_MODE_MDWRSZ_MASK;
  

•   }
  

•   if (plat->mode & SPI_3WIRE)
  

•           val |= SPI_PFL_MODE_3WIRE_MASK;
  

•   writel(val, priv->regs + SPI_PFL_MODE_REG(plat->cs));
  

•   /* transfer loop */
  

•   while (data_bytes > 0) {
  

•           size_t curr_step = min(step_size, data_bytes);
  

•           int ret;
  

•           /* copy tx data */
  

•           if (tx) {
  

•                   memcpy_toio(priv->regs + HSSPI_FIFO_BASE +
  

•                               HSSPI_FIFO_OP_SIZE, tx, curr_step);
  

•                   tx += curr_step;
  

•           }
  

•           /* set fifo operation */
  

•           writew(cpu_to_be16(opcode | (curr_step & HSSPI_FIFO_OP_BYTES_MASK)),
  

•                  priv->regs + HSSPI_FIFO_OP_REG);
  

•           /* make sure we keep cs active until spi transfer is done */
  

•           if (!cs_act) {
  

•                   bcmbca_hsspi_activate_cs(priv, plat);
  

•                   cs_act = 1;
  

•           }
  

•           /* issue the transfer */
  

•           val = SPI_CMD_OP_START;
  

•           val |= (plat->cs << SPI_CMD_PFL_SHIFT) &
  

•                     SPI_CMD_PFL_MASK;
  

•           val |= (plat->cs << SPI_CMD_SLAVE_SHIFT) &
  

•                     SPI_CMD_SLAVE_MASK;
  

•           writel(val, priv->regs + SPI_CMD_REG);
  

•           /* wait for completion */
  

•           ret = wait_for_bit_32(priv->regs + SPI_STAT_REG,
  

•                                 SPI_STAT_SRCBUSY_MASK, false,
  

•                                 1000, false);
  

•           if (ret) {
  

•                   bcmbca_hsspi_deactivate_cs(priv, plat);
  

•                   dev_err(dev, "interrupt timeout\n");
  

•                   return ret;
  

•           }
  

•           data_bytes -= curr_step;
  

•           if ((flags & SPI_XFER_END) && !data_bytes)
  

•                   bcmbca_hsspi_deactivate_cs(priv, plat);
  

•           /* copy rx data */
  

•           if (rx) {
  

•                   memcpy_fromio(rx, priv->regs + HSSPI_FIFO_BASE,
  

•                                 curr_step);
  

•                   rx += curr_step;
  

•           }
  

•   }
  

•   return 0;
  

+}

+static const struct dm_spi_ops bcmbca_hsspi_ops = {

•   .cs_info = bcmbca_hsspi_cs_info,
  

•   .set_mode = bcmbca_hsspi_set_mode,
  

•   .set_speed = bcmbca_hsspi_set_speed,
  

•   .xfer = bcmbca_hsspi_xfer,
  

+};

+static const struct udevice_id bcmbca_hsspi_ids[] = {

•   { .compatible = "brcm,bcmbca-hsspi-v1.1", },
  

•   { /* sentinel */ }
  

+};

+static int bcmbca_hsspi_child_pre_probe(struct udevice *dev) +{

•   struct bcmbca_hsspi_priv *priv = dev_get_priv(dev->parent);
  

•   struct dm_spi_slave_plat *plat = dev_get_parent_plat(dev);
  

•   u32 val;
  

•   /* check cs */
  

•   if (plat->cs >= priv->num_cs) {
  

•           dev_err(dev, "no cs %u\n", plat->cs);
  

•           return -EINVAL;
  

•   }
  

•   /* cs polarity */
  

•   if (plat->mode & SPI_CS_HIGH)
  

•           priv->cs_pols |= BIT(plat->cs);
  

•   else
  

•           priv->cs_pols &= ~BIT(plat->cs);
  

•   /* set the polarity to spim cs register */
  

•   val = readl(priv->spim_ctrl);
  

•   val &= ~BIT(plat->cs + SPIM_CTRL_CS_OVERRIDE_VAL_SHIFT);
  

•   if (priv->cs_pols & BIT(plat->cs))
  

•           val |= BIT(plat->cs + SPIM_CTRL_CS_OVERRIDE_VAL_SHIFT);
  

•   writel(val, priv->spim_ctrl);
  

What is this code for cannot we handle this via set_mode or xfer?

This is the new register introduced in this controller to allow the driver to override the cs signal high and low from the controller so driver can control it directly. In the old controller, driver has no control over cs at all. Here we preset the OVERRIDE_VAL based on the cs_pols setting so the actually bcmbca_hsspi_activate/deactivate_cs function just need to set the OVERRIDE_SEL bit. The bcmbca_hsspi_activate/deactivate_cs functions has to be called right befer and after the controller start/finish the transation so can not be set via set_mode and xfer

Jagan.