Tegra: T210: Add QSPI driver
authorTom Warren <twarren@nvidia.com>
Mon, 12 Oct 2015 21:50:54 +0000 (14:50 -0700)
committerTom Warren <twarren@nvidia.com>
Thu, 12 Nov 2015 16:21:07 +0000 (09:21 -0700)
This is the normal Tegra SPI driver modified to work with the
QSPI controller in Tegra210. It does not do 2x/4x transfers
or any other QSPI protocol.

Signed-off-by: Yen Lin <yelin@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>
drivers/spi/Kconfig
drivers/spi/Makefile
drivers/spi/tegra210_qspi.c [new file with mode: 0644]

index 7d7a9d0809493def7fa0fc38127509129cdcb713..a0dbd8b640d810e9a3812ec360db3816f68c4863 100644 (file)
@@ -123,6 +123,13 @@ config TEGRA20_SLINK
          be used to access the SPI NOR flash on platforms embedding this
          nVidia Tegra20/Tegra30 IP cores.
 
+config TEGRA210_QSPI
+       bool "nVidia Tegra210 QSPI driver"
+       help
+         Enable the Tegra Quad-SPI (QSPI) driver for T210. This driver
+         be used to access SPI chips on platforms embedding this
+         NVIDIA Tegra210 IP core.
+
 config XILINX_SPI
        bool "Xilinx SPI driver"
        help
index 637fea85449325f60d88cc43cc64253ff0835448..3eca7456d6a6bf865726fe27216365f30e6c1327 100644 (file)
@@ -46,6 +46,7 @@ obj-$(CONFIG_SH_QSPI) += sh_qspi.o
 obj-$(CONFIG_TEGRA114_SPI) += tegra114_spi.o
 obj-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
 obj-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
+obj-$(CONFIG_TEGRA210_QSPI) += tegra210_qspi.o
 obj-$(CONFIG_TI_QSPI) += ti_qspi.o
 obj-$(CONFIG_XILINX_SPI) += xilinx_spi.o
 obj-$(CONFIG_ZYNQ_SPI) += zynq_spi.o
diff --git a/drivers/spi/tegra210_qspi.c b/drivers/spi/tegra210_qspi.c
new file mode 100644 (file)
index 0000000..6bbbe93
--- /dev/null
@@ -0,0 +1,417 @@
+/*
+ * NVIDIA Tegra210 QSPI controller driver
+ *
+ * (C) Copyright 2015 NVIDIA Corporation <www.nvidia.com>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch-tegra/clk_rst.h>
+#include <spi.h>
+#include <fdtdec.h>
+#include "tegra_spi.h"
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* COMMAND1 */
+#define QSPI_CMD1_GO                   BIT(31)
+#define QSPI_CMD1_M_S                  BIT(30)
+#define QSPI_CMD1_MODE_MASK            GENMASK(1,0)
+#define QSPI_CMD1_MODE_SHIFT           28
+#define QSPI_CMD1_CS_SEL_MASK          GENMASK(1,0)
+#define QSPI_CMD1_CS_SEL_SHIFT         26
+#define QSPI_CMD1_CS_POL_INACTIVE0     BIT(22)
+#define QSPI_CMD1_CS_SW_HW             BIT(21)
+#define QSPI_CMD1_CS_SW_VAL            BIT(20)
+#define QSPI_CMD1_IDLE_SDA_MASK                GENMASK(1,0)
+#define QSPI_CMD1_IDLE_SDA_SHIFT       18
+#define QSPI_CMD1_BIDIR                        BIT(17)
+#define QSPI_CMD1_LSBI_FE              BIT(16)
+#define QSPI_CMD1_LSBY_FE              BIT(15)
+#define QSPI_CMD1_BOTH_EN_BIT          BIT(14)
+#define QSPI_CMD1_BOTH_EN_BYTE         BIT(13)
+#define QSPI_CMD1_RX_EN                        BIT(12)
+#define QSPI_CMD1_TX_EN                        BIT(11)
+#define QSPI_CMD1_PACKED               BIT(5)
+#define QSPI_CMD1_BITLEN_MASK          GENMASK(4,0)
+#define QSPI_CMD1_BITLEN_SHIFT         0
+
+/* COMMAND2 */
+#define QSPI_CMD2_TX_CLK_TAP_DELAY     BIT(6)
+#define QSPI_CMD2_TX_CLK_TAP_DELAY_MASK        GENMASK(11,6)
+#define QSPI_CMD2_RX_CLK_TAP_DELAY     BIT(0)
+#define QSPI_CMD2_RX_CLK_TAP_DELAY_MASK        GENMASK(5,0)
+
+/* TRANSFER STATUS */
+#define QSPI_XFER_STS_RDY              BIT(30)
+
+/* FIFO STATUS */
+#define QSPI_FIFO_STS_CS_INACTIVE      BIT(31)
+#define QSPI_FIFO_STS_FRAME_END                BIT(30)
+#define QSPI_FIFO_STS_RX_FIFO_FLUSH    BIT(15)
+#define QSPI_FIFO_STS_TX_FIFO_FLUSH    BIT(14)
+#define QSPI_FIFO_STS_ERR              BIT(8)
+#define QSPI_FIFO_STS_TX_FIFO_OVF      BIT(7)
+#define QSPI_FIFO_STS_TX_FIFO_UNR      BIT(6)
+#define QSPI_FIFO_STS_RX_FIFO_OVF      BIT(5)
+#define QSPI_FIFO_STS_RX_FIFO_UNR      BIT(4)
+#define QSPI_FIFO_STS_TX_FIFO_FULL     BIT(3)
+#define QSPI_FIFO_STS_TX_FIFO_EMPTY    BIT(2)
+#define QSPI_FIFO_STS_RX_FIFO_FULL     BIT(1)
+#define QSPI_FIFO_STS_RX_FIFO_EMPTY    BIT(0)
+
+#define QSPI_TIMEOUT           1000
+
+struct qspi_regs {
+       u32 command1;   /* 000:QSPI_COMMAND1 register */
+       u32 command2;   /* 004:QSPI_COMMAND2 register */
+       u32 timing1;    /* 008:QSPI_CS_TIM1 register */
+       u32 timing2;    /* 00c:QSPI_CS_TIM2 register */
+       u32 xfer_status;/* 010:QSPI_TRANS_STATUS register */
+       u32 fifo_status;/* 014:QSPI_FIFO_STATUS register */
+       u32 tx_data;    /* 018:QSPI_TX_DATA register */
+       u32 rx_data;    /* 01c:QSPI_RX_DATA register */
+       u32 dma_ctl;    /* 020:QSPI_DMA_CTL register */
+       u32 dma_blk;    /* 024:QSPI_DMA_BLK register */
+       u32 rsvd[56];   /* 028-107 reserved */
+       u32 tx_fifo;    /* 108:QSPI_FIFO1 register */
+       u32 rsvd2[31];  /* 10c-187 reserved */
+       u32 rx_fifo;    /* 188:QSPI_FIFO2 register */
+       u32 spare_ctl;  /* 18c:QSPI_SPARE_CTRL register */
+};
+
+struct tegra210_qspi_priv {
+       struct qspi_regs *regs;
+       unsigned int freq;
+       unsigned int mode;
+       int periph_id;
+       int valid;
+       int last_transaction_us;
+};
+
+static int tegra210_qspi_ofdata_to_platdata(struct udevice *bus)
+{
+       struct tegra_spi_platdata *plat = bus->platdata;
+       const void *blob = gd->fdt_blob;
+       int node = bus->of_offset;
+
+       plat->base = dev_get_addr(bus);
+       plat->periph_id = clock_decode_periph_id(blob, node);
+
+       if (plat->periph_id == PERIPH_ID_NONE) {
+               debug("%s: could not decode periph id %d\n", __func__,
+                     plat->periph_id);
+               return -FDT_ERR_NOTFOUND;
+       }
+
+       /* Use 500KHz as a suitable default */
+       plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
+                                       500000);
+       plat->deactivate_delay_us = fdtdec_get_int(blob, node,
+                                       "spi-deactivate-delay", 0);
+       debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
+             __func__, plat->base, plat->periph_id, plat->frequency,
+             plat->deactivate_delay_us);
+
+       return 0;
+}
+
+static int tegra210_qspi_probe(struct udevice *bus)
+{
+       struct tegra_spi_platdata *plat = dev_get_platdata(bus);
+       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+       priv->regs = (struct qspi_regs *)plat->base;
+
+       priv->last_transaction_us = timer_get_us();
+       priv->freq = plat->frequency;
+       priv->periph_id = plat->periph_id;
+
+       return 0;
+}
+
+static int tegra210_qspi_claim_bus(struct udevice *bus)
+{
+       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+       struct qspi_regs *regs = priv->regs;
+
+       /* Change SPI clock to correct frequency, PLLP_OUT0 source */
+       clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, priv->freq);
+
+       debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));
+
+       /* Set master mode and sw controlled CS */
+       setbits_le32(&regs->command1, QSPI_CMD1_M_S | QSPI_CMD1_CS_SW_HW |
+                    (priv->mode << QSPI_CMD1_MODE_SHIFT));
+       debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));
+
+       return 0;
+}
+
+/**
+ * Activate the CS by driving it LOW
+ *
+ * @param slave        Pointer to spi_slave to which controller has to
+ *             communicate with
+ */
+static void spi_cs_activate(struct udevice *dev)
+{
+       struct udevice *bus = dev->parent;
+       struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
+       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+       /* If it's too soon to do another transaction, wait */
+       if (pdata->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 < pdata->deactivate_delay_us)
+                       udelay(pdata->deactivate_delay_us - delay_us);
+       }
+
+       clrbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
+}
+
+/**
+ * Deactivate the CS by driving it HIGH
+ *
+ * @param slave        Pointer to spi_slave to which controller has to
+ *             communicate with
+ */
+static void spi_cs_deactivate(struct udevice *dev)
+{
+       struct udevice *bus = dev->parent;
+       struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
+       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+       setbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
+
+       /* Remember time of this transaction so we can honour the bus delay */
+       if (pdata->deactivate_delay_us)
+               priv->last_transaction_us = timer_get_us();
+
+       debug("Deactivate CS, bus '%s'\n", bus->name);
+}
+
+static int tegra210_qspi_xfer(struct udevice *dev, unsigned int bitlen,
+                            const void *data_out, void *data_in,
+                            unsigned long flags)
+{
+       struct udevice *bus = dev->parent;
+       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+       struct qspi_regs *regs = priv->regs;
+       u32 reg, tmpdout, tmpdin = 0;
+       const u8 *dout = data_out;
+       u8 *din = data_in;
+       int num_bytes, tm, ret;
+
+       debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
+             __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
+       if (bitlen % 8)
+               return -1;
+       num_bytes = bitlen / 8;
+
+       ret = 0;
+
+       /* clear all error status bits */
+       reg = readl(&regs->fifo_status);
+       writel(reg, &regs->fifo_status);
+
+       /* flush RX/TX FIFOs */
+       setbits_le32(&regs->fifo_status,
+                    (QSPI_FIFO_STS_RX_FIFO_FLUSH |
+                     QSPI_FIFO_STS_TX_FIFO_FLUSH));
+
+       tm = QSPI_TIMEOUT;
+       while ((tm && readl(&regs->fifo_status) &
+                     (QSPI_FIFO_STS_RX_FIFO_FLUSH |
+                      QSPI_FIFO_STS_TX_FIFO_FLUSH))) {
+               tm--;
+               udelay(1);
+       }
+
+       if (!tm) {
+               printf("%s: timeout during QSPI FIFO flush!\n",
+                      __func__);
+               return -1;
+       }
+
+       /*
+        * Notes:
+        *   1. don't set LSBY_FE, so no need to swap bytes from/to TX/RX FIFOs;
+        *   2. don't set RX_EN and TX_EN yet.
+        *      (SW needs to make sure that while programming the blk_size,
+        *       tx_en and rx_en bits must be zero)
+        *      [TODO] I (Yen Lin) have problems when both RX/TX EN bits are set
+        *             i.e., both dout and din are not NULL.
+        */
+       clrsetbits_le32(&regs->command1,
+                       (QSPI_CMD1_LSBI_FE | QSPI_CMD1_LSBY_FE |
+                        QSPI_CMD1_RX_EN | QSPI_CMD1_TX_EN),
+                       (spi_chip_select(dev) << QSPI_CMD1_CS_SEL_SHIFT));
+
+       /* set xfer size to 1 block (32 bits) */
+       writel(0, &regs->dma_blk);
+
+       if (flags & SPI_XFER_BEGIN)
+               spi_cs_activate(dev);
+
+       /* handle data in 32-bit chunks */
+       while (num_bytes > 0) {
+               int bytes;
+
+               tmpdout = 0;
+               bytes = (num_bytes > 4) ?  4 : num_bytes;
+
+               if (dout != NULL) {
+                       memcpy((void *)&tmpdout, (void *)dout, bytes);
+                       dout += bytes;
+                       num_bytes -= bytes;
+                       writel(tmpdout, &regs->tx_fifo);
+                       setbits_le32(&regs->command1, QSPI_CMD1_TX_EN);
+               }
+
+               if (din != NULL)
+                       setbits_le32(&regs->command1, QSPI_CMD1_RX_EN);
+
+               /* clear ready bit */
+               setbits_le32(&regs->xfer_status, QSPI_XFER_STS_RDY);
+
+               clrsetbits_le32(&regs->command1,
+                               QSPI_CMD1_BITLEN_MASK << QSPI_CMD1_BITLEN_SHIFT,
+                               (bytes * 8 - 1) << QSPI_CMD1_BITLEN_SHIFT);
+
+               /* Need to stabilize other reg bits before GO bit set.
+                * As per the TRM:
+                * "For successful operation at various freq combinations,
+                * a minimum of 4-5 spi_clk cycle delay might be required
+                * before enabling the PIO or DMA bits. The worst case delay
+                * calculation can be done considering slowest qspi_clk as
+                * 1MHz. Based on that 1us delay should be enough before
+                * enabling PIO or DMA." Padded another 1us for safety.
+                */
+               udelay(2);
+               setbits_le32(&regs->command1, QSPI_CMD1_GO);
+               udelay(1);
+
+               /*
+                * Wait for SPI transmit FIFO to empty, or to time out.
+                * The RX FIFO status will be read and cleared last
+                */
+               for (tm = 0; tm < QSPI_TIMEOUT; ++tm) {
+                       u32 fifo_status, xfer_status;
+
+                       xfer_status = readl(&regs->xfer_status);
+                       if (!(xfer_status & QSPI_XFER_STS_RDY))
+                               continue;
+
+                       fifo_status = readl(&regs->fifo_status);
+                       if (fifo_status & QSPI_FIFO_STS_ERR) {
+                               debug("%s: got a fifo error: ", __func__);
+                               if (fifo_status & QSPI_FIFO_STS_TX_FIFO_OVF)
+                                       debug("tx FIFO overflow ");
+                               if (fifo_status & QSPI_FIFO_STS_TX_FIFO_UNR)
+                                       debug("tx FIFO underrun ");
+                               if (fifo_status & QSPI_FIFO_STS_RX_FIFO_OVF)
+                                       debug("rx FIFO overflow ");
+                               if (fifo_status & QSPI_FIFO_STS_RX_FIFO_UNR)
+                                       debug("rx FIFO underrun ");
+                               if (fifo_status & QSPI_FIFO_STS_TX_FIFO_FULL)
+                                       debug("tx FIFO full ");
+                               if (fifo_status & QSPI_FIFO_STS_TX_FIFO_EMPTY)
+                                       debug("tx FIFO empty ");
+                               if (fifo_status & QSPI_FIFO_STS_RX_FIFO_FULL)
+                                       debug("rx FIFO full ");
+                               if (fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)
+                                       debug("rx FIFO empty ");
+                               debug("\n");
+                               break;
+                       }
+
+                       if (!(fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)) {
+                               tmpdin = readl(&regs->rx_fifo);
+                               if (din != NULL) {
+                                       memcpy(din, &tmpdin, bytes);
+                                       din += bytes;
+                                       num_bytes -= bytes;
+                               }
+                       }
+                       break;
+               }
+
+               if (tm >= QSPI_TIMEOUT)
+                       ret = tm;
+
+               /* clear ACK RDY, etc. bits */
+               writel(readl(&regs->fifo_status), &regs->fifo_status);
+       }
+
+       if (flags & SPI_XFER_END)
+               spi_cs_deactivate(dev);
+
+       debug("%s: transfer ended. Value=%08x, fifo_status = %08x\n",
+             __func__, tmpdin, readl(&regs->fifo_status));
+
+       if (ret) {
+               printf("%s: timeout during SPI transfer, tm %d\n",
+                      __func__, ret);
+               return -1;
+       }
+
+       return ret;
+}
+
+static int tegra210_qspi_set_speed(struct udevice *bus, uint speed)
+{
+       struct tegra_spi_platdata *plat = bus->platdata;
+       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+       if (speed > plat->frequency)
+               speed = plat->frequency;
+       priv->freq = speed;
+       debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
+
+       return 0;
+}
+
+static int tegra210_qspi_set_mode(struct udevice *bus, uint mode)
+{
+       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
+
+       priv->mode = mode;
+       debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
+
+       return 0;
+}
+
+static const struct dm_spi_ops tegra210_qspi_ops = {
+       .claim_bus      = tegra210_qspi_claim_bus,
+       .xfer           = tegra210_qspi_xfer,
+       .set_speed      = tegra210_qspi_set_speed,
+       .set_mode       = tegra210_qspi_set_mode,
+       /*
+        * cs_info is not needed, since we require all chip selects to be
+        * in the device tree explicitly
+        */
+};
+
+static const struct udevice_id tegra210_qspi_ids[] = {
+       { .compatible = "nvidia,tegra210-qspi" },
+       { }
+};
+
+U_BOOT_DRIVER(tegra210_qspi) = {
+       .name = "tegra210-qspi",
+       .id = UCLASS_SPI,
+       .of_match = tegra210_qspi_ids,
+       .ops = &tegra210_qspi_ops,
+       .ofdata_to_platdata = tegra210_qspi_ofdata_to_platdata,
+       .platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
+       .priv_auto_alloc_size = sizeof(struct tegra210_qspi_priv),
+       .per_child_auto_alloc_size = sizeof(struct spi_slave),
+       .probe = tegra210_qspi_probe,
+};