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linux/drivers/spi/atmel-quadspi.c

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/*
* Driver for Atmel QSPI Controller
*
* Copyright (C) 2015 Atmel Corporation
* Copyright (C) 2018 Cryptera A/S
*
* Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
* Author: Piotr Bugalski <bugalski.piotr@gmail.com>
*
* 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
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
* This driver is based on drivers/mtd/spi-nor/fsl-quadspi.c from Freescale.
*/
#include <linux/kernel.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/spi/spi-mem.h>
/* QSPI register offsets */
#define QSPI_CR 0x0000 /* Control Register */
#define QSPI_MR 0x0004 /* Mode Register */
#define QSPI_RD 0x0008 /* Receive Data Register */
#define QSPI_TD 0x000c /* Transmit Data Register */
#define QSPI_SR 0x0010 /* Status Register */
#define QSPI_IER 0x0014 /* Interrupt Enable Register */
#define QSPI_IDR 0x0018 /* Interrupt Disable Register */
#define QSPI_IMR 0x001c /* Interrupt Mask Register */
#define QSPI_SCR 0x0020 /* Serial Clock Register */
#define QSPI_IAR 0x0030 /* Instruction Address Register */
#define QSPI_ICR 0x0034 /* Instruction Code Register */
#define QSPI_IFR 0x0038 /* Instruction Frame Register */
#define QSPI_SMR 0x0040 /* Scrambling Mode Register */
#define QSPI_SKR 0x0044 /* Scrambling Key Register */
#define QSPI_WPMR 0x00E4 /* Write Protection Mode Register */
#define QSPI_WPSR 0x00E8 /* Write Protection Status Register */
#define QSPI_VERSION 0x00FC /* Version Register */
/* Bitfields in QSPI_CR (Control Register) */
#define QSPI_CR_QSPIEN BIT(0)
#define QSPI_CR_QSPIDIS BIT(1)
#define QSPI_CR_SWRST BIT(7)
#define QSPI_CR_LASTXFER BIT(24)
/* Bitfields in QSPI_MR (Mode Register) */
#define QSPI_MR_SMM BIT(0)
#define QSPI_MR_LLB BIT(1)
#define QSPI_MR_WDRBT BIT(2)
#define QSPI_MR_SMRM BIT(3)
#define QSPI_MR_CSMODE_MASK GENMASK(5, 4)
#define QSPI_MR_CSMODE_NOT_RELOADED (0 << 4)
#define QSPI_MR_CSMODE_LASTXFER (1 << 4)
#define QSPI_MR_CSMODE_SYSTEMATICALLY (2 << 4)
#define QSPI_MR_NBBITS_MASK GENMASK(11, 8)
#define QSPI_MR_NBBITS(n) ((((n) - 8) << 8) & QSPI_MR_NBBITS_MASK)
#define QSPI_MR_DLYBCT_MASK GENMASK(23, 16)
#define QSPI_MR_DLYBCT(n) (((n) << 16) & QSPI_MR_DLYBCT_MASK)
#define QSPI_MR_DLYCS_MASK GENMASK(31, 24)
#define QSPI_MR_DLYCS(n) (((n) << 24) & QSPI_MR_DLYCS_MASK)
/* Bitfields in QSPI_SR/QSPI_IER/QSPI_IDR/QSPI_IMR */
#define QSPI_SR_RDRF BIT(0)
#define QSPI_SR_TDRE BIT(1)
#define QSPI_SR_TXEMPTY BIT(2)
#define QSPI_SR_OVRES BIT(3)
#define QSPI_SR_CSR BIT(8)
#define QSPI_SR_CSS BIT(9)
#define QSPI_SR_INSTRE BIT(10)
#define QSPI_SR_QSPIENS BIT(24)
#define QSPI_SR_CMD_COMPLETED (QSPI_SR_INSTRE | QSPI_SR_CSR)
/* Bitfields in QSPI_SCR (Serial Clock Register) */
#define QSPI_SCR_CPOL BIT(0)
#define QSPI_SCR_CPHA BIT(1)
#define QSPI_SCR_SCBR_MASK GENMASK(15, 8)
#define QSPI_SCR_SCBR(n) (((n) << 8) & QSPI_SCR_SCBR_MASK)
#define QSPI_SCR_DLYBS_MASK GENMASK(23, 16)
#define QSPI_SCR_DLYBS(n) (((n) << 16) & QSPI_SCR_DLYBS_MASK)
/* Bitfields in QSPI_ICR (Instruction Code Register) */
#define QSPI_ICR_INST_MASK GENMASK(7, 0)
#define QSPI_ICR_INST(inst) (((inst) << 0) & QSPI_ICR_INST_MASK)
#define QSPI_ICR_OPT_MASK GENMASK(23, 16)
#define QSPI_ICR_OPT(opt) (((opt) << 16) & QSPI_ICR_OPT_MASK)
/* Bitfields in QSPI_IFR (Instruction Frame Register) */
#define QSPI_IFR_WIDTH_MASK GENMASK(2, 0)
#define QSPI_IFR_WIDTH_SINGLE_BIT_SPI (0 << 0)
#define QSPI_IFR_WIDTH_DUAL_OUTPUT (1 << 0)
#define QSPI_IFR_WIDTH_QUAD_OUTPUT (2 << 0)
#define QSPI_IFR_WIDTH_DUAL_IO (3 << 0)
#define QSPI_IFR_WIDTH_QUAD_IO (4 << 0)
#define QSPI_IFR_WIDTH_DUAL_CMD (5 << 0)
#define QSPI_IFR_WIDTH_QUAD_CMD (6 << 0)
#define QSPI_IFR_INSTEN BIT(4)
#define QSPI_IFR_ADDREN BIT(5)
#define QSPI_IFR_OPTEN BIT(6)
#define QSPI_IFR_DATAEN BIT(7)
#define QSPI_IFR_OPTL_MASK GENMASK(9, 8)
#define QSPI_IFR_OPTL_1BIT (0 << 8)
#define QSPI_IFR_OPTL_2BIT (1 << 8)
#define QSPI_IFR_OPTL_4BIT (2 << 8)
#define QSPI_IFR_OPTL_8BIT (3 << 8)
#define QSPI_IFR_ADDRL BIT(10)
#define QSPI_IFR_TFRTYP_MASK GENMASK(13, 12)
#define QSPI_IFR_TFRTYP_TRSFR_READ (0 << 12)
#define QSPI_IFR_TFRTYP_TRSFR_READ_MEM (1 << 12)
#define QSPI_IFR_TFRTYP_TRSFR_WRITE (2 << 12)
#define QSPI_IFR_TFRTYP_TRSFR_WRITE_MEM (3 << 13)
#define QSPI_IFR_CRM BIT(14)
#define QSPI_IFR_NBDUM_MASK GENMASK(20, 16)
#define QSPI_IFR_NBDUM(n) (((n) << 16) & QSPI_IFR_NBDUM_MASK)
/* Bitfields in QSPI_SMR (Scrambling Mode Register) */
#define QSPI_SMR_SCREN BIT(0)
#define QSPI_SMR_RVDIS BIT(1)
/* Bitfields in QSPI_WPMR (Write Protection Mode Register) */
#define QSPI_WPMR_WPEN BIT(0)
#define QSPI_WPMR_WPKEY_MASK GENMASK(31, 8)
#define QSPI_WPMR_WPKEY(wpkey) (((wpkey) << 8) & QSPI_WPMR_WPKEY_MASK)
/* Bitfields in QSPI_WPSR (Write Protection Status Register) */
#define QSPI_WPSR_WPVS BIT(0)
#define QSPI_WPSR_WPVSRC_MASK GENMASK(15, 8)
#define QSPI_WPSR_WPVSRC(src) (((src) << 8) & QSPI_WPSR_WPVSRC)
struct atmel_qspi {
void __iomem *regs;
void __iomem *mem;
struct clk *clk;
struct platform_device *pdev;
u32 pending;
struct completion cmd_completion;
};
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)
{
return readl_relaxed(aq->regs + reg);
}
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;
}
const char *atmel_qspi_get_name(struct spi_mem *spimem)
{
return dev_name(spimem->spi->dev.parent);
}
static const struct spi_controller_mem_ops atmel_qspi_mem_ops = {
.supports_op = atmel_qspi_supports_op,
.exec_op = atmel_qspi_exec_op,
.get_name = atmel_qspi_get_name
};
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_init(struct atmel_qspi *aq)
{
/* Reset the QSPI controller */
qspi_writel(aq, QSPI_CR, QSPI_CR_SWRST);
/* Enable the QSPI controller */
qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIEN);
return 0;
}
static irqreturn_t atmel_qspi_interrupt(int irq, void *dev_id)
{
struct atmel_qspi *aq = (struct atmel_qspi *)dev_id;
u32 status, mask, pending;
status = qspi_readl(aq, QSPI_SR);
mask = qspi_readl(aq, QSPI_IMR);
pending = status & mask;
if (!pending)
return IRQ_NONE;
aq->pending |= pending;
if ((aq->pending & QSPI_SR_CMD_COMPLETED) == QSPI_SR_CMD_COMPLETED)
complete(&aq->cmd_completion);
return IRQ_HANDLED;
}
static int atmel_qspi_probe(struct platform_device *pdev)
{
struct spi_controller *ctrl;
struct atmel_qspi *aq;
struct resource *res;
int irq, err = 0;
ctrl = spi_alloc_master(&pdev->dev, sizeof(*aq));
if (!ctrl)
return -ENOMEM;
ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD | SPI_TX_DUAL | SPI_TX_QUAD;
ctrl->setup = atmel_qspi_setup;
ctrl->bus_num = -1;
ctrl->mem_ops = &atmel_qspi_mem_ops;
ctrl->num_chipselect = 1;
ctrl->dev.of_node = pdev->dev.of_node;
platform_set_drvdata(pdev, ctrl);
aq = spi_controller_get_devdata(ctrl);
init_completion(&aq->cmd_completion);
aq->pdev = pdev;
/* Map the registers */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
aq->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(aq->regs)) {
dev_err(&pdev->dev, "missing registers\n");
err = PTR_ERR(aq->regs);
goto exit;
}
/* Map the AHB memory */
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_mmap");
aq->mem = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(aq->mem)) {
dev_err(&pdev->dev, "missing AHB memory\n");
err = PTR_ERR(aq->mem);
goto exit;
}
/* Get the peripheral clock */
aq->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(aq->clk)) {
dev_err(&pdev->dev, "missing peripheral clock\n");
err = PTR_ERR(aq->clk);
goto exit;
}
/* Enable the peripheral clock */
err = clk_prepare_enable(aq->clk);
if (err) {
dev_err(&pdev->dev, "failed to enable the peripheral clock\n");
goto exit;
}
/* Request the IRQ */
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "missing IRQ\n");
err = irq;
goto disable_clk;
}
err = devm_request_irq(&pdev->dev, irq, atmel_qspi_interrupt,
0, dev_name(&pdev->dev), aq);
if (err)
goto disable_clk;
err = atmel_qspi_init(aq);
if (err)
goto disable_clk;
err = spi_register_controller(ctrl);
if (err)
goto disable_clk;
return 0;
disable_clk:
clk_disable_unprepare(aq->clk);
exit:
spi_controller_put(ctrl);
return err;
}
static int atmel_qspi_remove(struct platform_device *pdev)
{
struct spi_controller *ctrl = platform_get_drvdata(pdev);
struct atmel_qspi *aq = spi_controller_get_devdata(ctrl);
spi_unregister_controller(ctrl);
qspi_writel(aq, QSPI_CR, QSPI_CR_QSPIDIS);
clk_disable_unprepare(aq->clk);
return 0;
}
static int __maybe_unused atmel_qspi_suspend(struct device *dev)
{
struct atmel_qspi *aq = dev_get_drvdata(dev);
clk_disable_unprepare(aq->clk);
return 0;
}
static int __maybe_unused atmel_qspi_resume(struct device *dev)
{
struct atmel_qspi *aq = dev_get_drvdata(dev);
clk_prepare_enable(aq->clk);
return atmel_qspi_init(aq);
}
static SIMPLE_DEV_PM_OPS(atmel_qspi_pm_ops, atmel_qspi_suspend,
atmel_qspi_resume);
static const struct of_device_id atmel_qspi_dt_ids[] = {
{ .compatible = "atmel,sama5d2-qspi" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, atmel_qspi_dt_ids);
static struct platform_driver atmel_qspi_driver = {
.driver = {
.name = "atmel_qspi",
.of_match_table = atmel_qspi_dt_ids,
.pm = &atmel_qspi_pm_ops,
},
.probe = atmel_qspi_probe,
.remove = atmel_qspi_remove,
};
module_platform_driver(atmel_qspi_driver);
MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>");
MODULE_AUTHOR("Piotr Bugalski <bugalski.piotr@gmail.com");
MODULE_DESCRIPTION("Atmel QSPI Controller driver");
MODULE_LICENSE("GPL v2");
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