This patch adds new interface to existing driver. New code is not used yet,
it will be enabled later.
Changes are prepared in small steps to keep patches readable.
Suggested-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
Signed-off-by: Piotr Bugalski <pbu@xxxxxxxxxxxx>
---
drivers/mtd/spi-nor/atmel-quadspi.c | 205 ++++++++++++++++++++++++++++++++++++
1 file changed, 205 insertions(+)
diff --git a/drivers/mtd/spi-nor/atmel-quadspi.c b/drivers/mtd/spi-nor/atmel-quadspi.c
index bdbfaa632dbf..c36fcecd569a 100644
--- a/drivers/mtd/spi-nor/atmel-quadspi.c
+++ b/drivers/mtd/spi-nor/atmel-quadspi.c
@@ -2,8 +2,10 @@
* Driver for Atmel QSPI Controller
*
* Copyright (C) 2015 Atmel Corporation
+ * Copyright (C) 2018 Cryptera A/S
*
* Author: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
+ * Author: Piotr Bugalski <pbu@xxxxxxxxxxxx>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -35,6 +37,7 @@
#include <linux/io.h>
#include <linux/gpio.h>
+#include <linux/spi/spi-mem.h>
/* QSPI register offsets */
#define QSPI_CR 0x0000 /* Control Register */
@@ -186,6 +189,23 @@ struct atmel_qspi_command {
void *rx_buf;
};
+struct qspi_mode {
+ u8 cmd_buswidth;
+ u8 addr_buswidth;
+ u8 data_buswidth;
+ u32 config;
+};
+
+static const struct qspi_mode sama5d2_qspi_modes[] = {
+ { 1, 1, 1, QSPI_IFR_WIDTH_SINGLE_BIT_SPI },
+ { 1, 1, 2, QSPI_IFR_WIDTH_DUAL_OUTPUT },
+ { 1, 1, 4, QSPI_IFR_WIDTH_QUAD_OUTPUT },
+ { 1, 2, 2, QSPI_IFR_WIDTH_DUAL_IO },
+ { 1, 4, 4, QSPI_IFR_WIDTH_QUAD_IO },
+ { 2, 2, 2, QSPI_IFR_WIDTH_DUAL_CMD },
+ { 4, 4, 4, QSPI_IFR_WIDTH_QUAD_CMD },
+};
+
/* Register access functions */
static inline u32 qspi_readl(struct atmel_qspi *aq, u32 reg)
{
@@ -197,6 +217,190 @@ static inline void qspi_writel(struct atmel_qspi *aq, u32 reg, u32 value)
writel_relaxed(value, aq->regs + reg);
}
+static inline bool is_compatible(const struct spi_mem_op *op,
+ const struct qspi_mode *mode)
+{
+ if (op->cmd.buswidth != mode->cmd_buswidth)
+ return false;
+
+ if (op->addr.nbytes && op->addr.buswidth != mode->addr_buswidth)
+ return false;
+
+ if (op->data.nbytes && op->data.buswidth != mode->data_buswidth)
+ return false;
+
+ return true;
+}
+
+static int find_mode(const struct spi_mem_op *op)
+{
+ u32 i;
+
+ for (i = 0; i < ARRAY_SIZE(sama5d2_qspi_modes); i++)
+ if (is_compatible(op, &sama5d2_qspi_modes[i]))
+ return i;
+
+ return -1;
+}
+
+static bool atmel_qspi_supports_op(struct spi_mem *mem,
+ const struct spi_mem_op *op)
+{
+ if (find_mode(op) < 0)
+ return false;
+
+ /* special case not supported by hardware */
+ if (op->addr.nbytes == 2 && op->cmd.buswidth != op->addr.buswidth &&
+ op->dummy.nbytes == 0)
+ return false;
+
+ return true;
+}
+
+static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+ struct atmel_qspi *aq = spi_controller_get_devdata(mem->spi->master);
+ int mode;
+ u32 dummy_cycles = 0;
+ u32 iar, icr, ifr, sr;
+ int err = 0;
+
+ iar = 0;
+ icr = QSPI_ICR_INST(op->cmd.opcode);
+ ifr = QSPI_IFR_INSTEN;
+
+ qspi_writel(aq, QSPI_MR, QSPI_MR_SMM);
+
+ mode = find_mode(op);
+ if (mode < 0)
+ return -ENOTSUPP;
+
+ ifr |= sama5d2_qspi_modes[mode].config;
+
+ if (op->dummy.buswidth && op->dummy.nbytes)
+ dummy_cycles = op->dummy.nbytes * 8 / op->dummy.buswidth;
+
+ if (op->addr.buswidth) {
+ switch (op->addr.nbytes) {
+ case 0:
+ break;
+ case 1:
+ ifr |= QSPI_IFR_OPTEN | QSPI_IFR_OPTL_8BIT;
+ icr |= QSPI_ICR_OPT(op->addr.val & 0xff);
+ break;
+ case 2:
+ if (dummy_cycles < 8 / op->addr.buswidth) {
+ ifr &= ~QSPI_IFR_INSTEN;
+ ifr |= QSPI_IFR_ADDREN;
+ iar = (op->cmd.opcode << 16) |
+ (op->addr.val & 0xffff);
+ } else {
+ ifr |= QSPI_IFR_ADDREN;
+ iar = (op->addr.val << 8) & 0xffffff;
+ dummy_cycles -= 8 / op->addr.buswidth;
+ }
+ break;
+ case 3:
+ ifr |= QSPI_IFR_ADDREN;
+ iar = op->addr.val & 0xffffff;
+ break;
+ case 4:
+ ifr |= QSPI_IFR_ADDREN | QSPI_IFR_ADDRL;
+ iar = op->addr.val & 0x7ffffff;
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+ }
+
+ /* Set number of dummy cycles */
+ if (dummy_cycles)
+ ifr |= QSPI_IFR_NBDUM(dummy_cycles);
+
+ /* Set data enable */
+ if (op->data.nbytes)
+ ifr |= QSPI_IFR_DATAEN;
+
+ if (op->data.dir == SPI_MEM_DATA_IN && op->data.nbytes)
+ ifr |= QSPI_IFR_TFRTYP_TRSFR_READ;
+ else
+ ifr |= QSPI_IFR_TFRTYP_TRSFR_WRITE;
+
+ /* Clear pending interrupts */
+ (void)qspi_readl(aq, QSPI_SR);
+
+ /* Set QSPI Instruction Frame registers */
+ qspi_writel(aq, QSPI_IAR, iar);
+ qspi_writel(aq, QSPI_ICR, icr);
+ qspi_writel(aq, QSPI_IFR, ifr);
+
+ /* Skip to the final steps if there is no data */
+ if (op->data.nbytes) {
+ /* Dummy read of QSPI_IFR to synchronize APB and AHB accesses */
+ (void)qspi_readl(aq, QSPI_IFR);
+
+ /* Send/Receive data */
+ if (op->data.dir == SPI_MEM_DATA_IN)
+ _memcpy_fromio(op->data.buf.in,
+ aq->mem + iar, op->data.nbytes);
+ else
+ _memcpy_toio(aq->mem + iar,
+ op->data.buf.out, op->data.nbytes);
+
+ /* Release the chip-select */
+ qspi_writel(aq, QSPI_CR, QSPI_CR_LASTXFER);
+ }
+
+ /* Poll INSTRuction End status */
+ sr = qspi_readl(aq, QSPI_SR);
+ if ((sr & QSPI_SR_CMD_COMPLETED) == QSPI_SR_CMD_COMPLETED)
+ return err;
+
+ /* Wait for INSTRuction End interrupt */
+ reinit_completion(&aq->cmd_completion);
+ aq->pending = sr & QSPI_SR_CMD_COMPLETED;
+ qspi_writel(aq, QSPI_IER, QSPI_SR_CMD_COMPLETED);
+ if (!wait_for_completion_timeout(&aq->cmd_completion,
+ msecs_to_jiffies(1000)))
+ err = -ETIMEDOUT;
+ qspi_writel(aq, QSPI_IDR, QSPI_SR_CMD_COMPLETED);
+
+ return err;
+}
+
+static const struct spi_controller_mem_ops atmel_qspi_mem_ops = {
+ .supports_op = atmel_qspi_supports_op,
+ .exec_op = atmel_qspi_exec_op
+};
+
+static int atmel_qspi_setup(struct spi_device *spi)
+{
+ struct spi_controller *ctrl = spi->master;
+ struct atmel_qspi *aq = spi_controller_get_devdata(ctrl);
+ unsigned long src_rate;
+ u32 scr, scbr;
+
+ if (ctrl->busy)
+ return -EBUSY;
+
+ if (!spi->max_speed_hz)
+ return -EINVAL;
+
+ src_rate = clk_get_rate(aq->clk);
+ if (!src_rate)
+ return -EINVAL;
+
+ /* Compute the QSPI baudrate */
+ scbr = DIV_ROUND_UP(src_rate, spi->max_speed_hz);
+ if (scbr > 0)
+ scbr--;
+
+ scr = QSPI_SCR_SCBR(scbr);
+ qspi_writel(aq, QSPI_SCR, scr);
+
+ return 0;
+}
+
static int atmel_qspi_run_transfer(struct atmel_qspi *aq,
const struct atmel_qspi_command *cmd)
{
@@ -756,5 +960,6 @@ static struct platform_driver atmel_qspi_driver = {
module_platform_driver(atmel_qspi_driver);
MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>");
+MODULE_AUTHOR("Piotr Bugalski <pbu@xxxxxxxxxxxx");
MODULE_DESCRIPTION("Atmel QSPI Controller driver");
MODULE_LICENSE("GPL v2");
--
2.11.0
--
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