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linux-sg2042/drivers/spi/spi-zynqmp-gqspi.c

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/*
* Xilinx Zynq UltraScale+ MPSoC Quad-SPI (QSPI) controller driver
* (master mode only)
*
* Copyright (C) 2009 - 2015 Xilinx, Inc.
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
/* Generic QSPI register offsets */
#define GQSPI_CONFIG_OFST 0x00000100
#define GQSPI_ISR_OFST 0x00000104
#define GQSPI_IDR_OFST 0x0000010C
#define GQSPI_IER_OFST 0x00000108
#define GQSPI_IMASK_OFST 0x00000110
#define GQSPI_EN_OFST 0x00000114
#define GQSPI_TXD_OFST 0x0000011C
#define GQSPI_RXD_OFST 0x00000120
#define GQSPI_TX_THRESHOLD_OFST 0x00000128
#define GQSPI_RX_THRESHOLD_OFST 0x0000012C
#define GQSPI_LPBK_DLY_ADJ_OFST 0x00000138
#define GQSPI_GEN_FIFO_OFST 0x00000140
#define GQSPI_SEL_OFST 0x00000144
#define GQSPI_GF_THRESHOLD_OFST 0x00000150
#define GQSPI_FIFO_CTRL_OFST 0x0000014C
#define GQSPI_QSPIDMA_DST_CTRL_OFST 0x0000080C
#define GQSPI_QSPIDMA_DST_SIZE_OFST 0x00000804
#define GQSPI_QSPIDMA_DST_STS_OFST 0x00000808
#define GQSPI_QSPIDMA_DST_I_STS_OFST 0x00000814
#define GQSPI_QSPIDMA_DST_I_EN_OFST 0x00000818
#define GQSPI_QSPIDMA_DST_I_DIS_OFST 0x0000081C
#define GQSPI_QSPIDMA_DST_I_MASK_OFST 0x00000820
#define GQSPI_QSPIDMA_DST_ADDR_OFST 0x00000800
#define GQSPI_QSPIDMA_DST_ADDR_MSB_OFST 0x00000828
/* GQSPI register bit masks */
#define GQSPI_SEL_MASK 0x00000001
#define GQSPI_EN_MASK 0x00000001
#define GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK 0x00000020
#define GQSPI_ISR_WR_TO_CLR_MASK 0x00000002
#define GQSPI_IDR_ALL_MASK 0x00000FBE
#define GQSPI_CFG_MODE_EN_MASK 0xC0000000
#define GQSPI_CFG_GEN_FIFO_START_MODE_MASK 0x20000000
#define GQSPI_CFG_ENDIAN_MASK 0x04000000
#define GQSPI_CFG_EN_POLL_TO_MASK 0x00100000
#define GQSPI_CFG_WP_HOLD_MASK 0x00080000
#define GQSPI_CFG_BAUD_RATE_DIV_MASK 0x00000038
#define GQSPI_CFG_CLK_PHA_MASK 0x00000004
#define GQSPI_CFG_CLK_POL_MASK 0x00000002
#define GQSPI_CFG_START_GEN_FIFO_MASK 0x10000000
#define GQSPI_GENFIFO_IMM_DATA_MASK 0x000000FF
#define GQSPI_GENFIFO_DATA_XFER 0x00000100
#define GQSPI_GENFIFO_EXP 0x00000200
#define GQSPI_GENFIFO_MODE_SPI 0x00000400
#define GQSPI_GENFIFO_MODE_DUALSPI 0x00000800
#define GQSPI_GENFIFO_MODE_QUADSPI 0x00000C00
#define GQSPI_GENFIFO_MODE_MASK 0x00000C00
#define GQSPI_GENFIFO_CS_LOWER 0x00001000
#define GQSPI_GENFIFO_CS_UPPER 0x00002000
#define GQSPI_GENFIFO_BUS_LOWER 0x00004000
#define GQSPI_GENFIFO_BUS_UPPER 0x00008000
#define GQSPI_GENFIFO_BUS_BOTH 0x0000C000
#define GQSPI_GENFIFO_BUS_MASK 0x0000C000
#define GQSPI_GENFIFO_TX 0x00010000
#define GQSPI_GENFIFO_RX 0x00020000
#define GQSPI_GENFIFO_STRIPE 0x00040000
#define GQSPI_GENFIFO_POLL 0x00080000
#define GQSPI_GENFIFO_EXP_START 0x00000100
#define GQSPI_FIFO_CTRL_RST_RX_FIFO_MASK 0x00000004
#define GQSPI_FIFO_CTRL_RST_TX_FIFO_MASK 0x00000002
#define GQSPI_FIFO_CTRL_RST_GEN_FIFO_MASK 0x00000001
#define GQSPI_ISR_RXEMPTY_MASK 0x00000800
#define GQSPI_ISR_GENFIFOFULL_MASK 0x00000400
#define GQSPI_ISR_GENFIFONOT_FULL_MASK 0x00000200
#define GQSPI_ISR_TXEMPTY_MASK 0x00000100
#define GQSPI_ISR_GENFIFOEMPTY_MASK 0x00000080
#define GQSPI_ISR_RXFULL_MASK 0x00000020
#define GQSPI_ISR_RXNEMPTY_MASK 0x00000010
#define GQSPI_ISR_TXFULL_MASK 0x00000008
#define GQSPI_ISR_TXNOT_FULL_MASK 0x00000004
#define GQSPI_ISR_POLL_TIME_EXPIRE_MASK 0x00000002
#define GQSPI_IER_TXNOT_FULL_MASK 0x00000004
#define GQSPI_IER_RXEMPTY_MASK 0x00000800
#define GQSPI_IER_POLL_TIME_EXPIRE_MASK 0x00000002
#define GQSPI_IER_RXNEMPTY_MASK 0x00000010
#define GQSPI_IER_GENFIFOEMPTY_MASK 0x00000080
#define GQSPI_IER_TXEMPTY_MASK 0x00000100
#define GQSPI_QSPIDMA_DST_INTR_ALL_MASK 0x000000FE
#define GQSPI_QSPIDMA_DST_STS_WTC 0x0000E000
#define GQSPI_CFG_MODE_EN_DMA_MASK 0x80000000
#define GQSPI_ISR_IDR_MASK 0x00000994
#define GQSPI_QSPIDMA_DST_I_EN_DONE_MASK 0x00000002
#define GQSPI_QSPIDMA_DST_I_STS_DONE_MASK 0x00000002
#define GQSPI_IRQ_MASK 0x00000980
#define GQSPI_CFG_BAUD_RATE_DIV_SHIFT 3
#define GQSPI_GENFIFO_CS_SETUP 0x4
#define GQSPI_GENFIFO_CS_HOLD 0x3
#define GQSPI_TXD_DEPTH 64
#define GQSPI_RX_FIFO_THRESHOLD 32
#define GQSPI_RX_FIFO_FILL (GQSPI_RX_FIFO_THRESHOLD * 4)
#define GQSPI_TX_FIFO_THRESHOLD_RESET_VAL 32
#define GQSPI_TX_FIFO_FILL (GQSPI_TXD_DEPTH -\
GQSPI_TX_FIFO_THRESHOLD_RESET_VAL)
#define GQSPI_GEN_FIFO_THRESHOLD_RESET_VAL 0X10
#define GQSPI_QSPIDMA_DST_CTRL_RESET_VAL 0x803FFA00
#define GQSPI_SELECT_FLASH_CS_LOWER 0x1
#define GQSPI_SELECT_FLASH_CS_UPPER 0x2
#define GQSPI_SELECT_FLASH_CS_BOTH 0x3
#define GQSPI_SELECT_FLASH_BUS_LOWER 0x1
#define GQSPI_SELECT_FLASH_BUS_UPPER 0x2
#define GQSPI_SELECT_FLASH_BUS_BOTH 0x3
#define GQSPI_BAUD_DIV_MAX 7 /* Baud rate divisor maximum */
#define GQSPI_BAUD_DIV_SHIFT 2 /* Baud rate divisor shift */
#define GQSPI_SELECT_MODE_SPI 0x1
#define GQSPI_SELECT_MODE_DUALSPI 0x2
#define GQSPI_SELECT_MODE_QUADSPI 0x4
#define GQSPI_DMA_UNALIGN 0x3
#define GQSPI_DEFAULT_NUM_CS 1 /* Default number of chip selects */
enum mode_type {GQSPI_MODE_IO, GQSPI_MODE_DMA};
/**
* struct zynqmp_qspi - Defines qspi driver instance
* @regs: Virtual address of the QSPI controller registers
* @refclk: Pointer to the peripheral clock
* @pclk: Pointer to the APB clock
* @irq: IRQ number
* @dev: Pointer to struct device
* @txbuf: Pointer to the TX buffer
* @rxbuf: Pointer to the RX buffer
* @bytes_to_transfer: Number of bytes left to transfer
* @bytes_to_receive: Number of bytes left to receive
* @genfifocs: Used for chip select
* @genfifobus: Used to select the upper or lower bus
* @dma_rx_bytes: Remaining bytes to receive by DMA mode
* @dma_addr: DMA address after mapping the kernel buffer
* @genfifoentry: Used for storing the genfifoentry instruction.
* @mode: Defines the mode in which QSPI is operating
*/
struct zynqmp_qspi {
void __iomem *regs;
struct clk *refclk;
struct clk *pclk;
int irq;
struct device *dev;
const void *txbuf;
void *rxbuf;
int bytes_to_transfer;
int bytes_to_receive;
u32 genfifocs;
u32 genfifobus;
u32 dma_rx_bytes;
dma_addr_t dma_addr;
u32 genfifoentry;
enum mode_type mode;
};
/**
* zynqmp_gqspi_read: For GQSPI controller read operation
* @xqspi: Pointer to the zynqmp_qspi structure
* @offset: Offset from where to read
*/
static u32 zynqmp_gqspi_read(struct zynqmp_qspi *xqspi, u32 offset)
{
return readl_relaxed(xqspi->regs + offset);
}
/**
* zynqmp_gqspi_write: For GQSPI controller write operation
* @xqspi: Pointer to the zynqmp_qspi structure
* @offset: Offset where to write
* @val: Value to be written
*/
static inline void zynqmp_gqspi_write(struct zynqmp_qspi *xqspi, u32 offset,
u32 val)
{
writel_relaxed(val, (xqspi->regs + offset));
}
/**
* zynqmp_gqspi_selectslave: For selection of slave device
* @instanceptr: Pointer to the zynqmp_qspi structure
* @flashcs: For chip select
* @flashbus: To check which bus is selected- upper or lower
*/
static void zynqmp_gqspi_selectslave(struct zynqmp_qspi *instanceptr,
u8 slavecs, u8 slavebus)
{
/*
* Bus and CS lines selected here will be updated in the instance and
* used for subsequent GENFIFO entries during transfer.
*/
/* Choose slave select line */
switch (slavecs) {
case GQSPI_SELECT_FLASH_CS_BOTH:
instanceptr->genfifocs = GQSPI_GENFIFO_CS_LOWER |
GQSPI_GENFIFO_CS_UPPER;
case GQSPI_SELECT_FLASH_CS_UPPER:
instanceptr->genfifocs = GQSPI_GENFIFO_CS_UPPER;
break;
case GQSPI_SELECT_FLASH_CS_LOWER:
instanceptr->genfifocs = GQSPI_GENFIFO_CS_LOWER;
break;
default:
dev_warn(instanceptr->dev, "Invalid slave select\n");
}
/* Choose the bus */
switch (slavebus) {
case GQSPI_SELECT_FLASH_BUS_BOTH:
instanceptr->genfifobus = GQSPI_GENFIFO_BUS_LOWER |
GQSPI_GENFIFO_BUS_UPPER;
break;
case GQSPI_SELECT_FLASH_BUS_UPPER:
instanceptr->genfifobus = GQSPI_GENFIFO_BUS_UPPER;
break;
case GQSPI_SELECT_FLASH_BUS_LOWER:
instanceptr->genfifobus = GQSPI_GENFIFO_BUS_LOWER;
break;
default:
dev_warn(instanceptr->dev, "Invalid slave bus\n");
}
}
/**
* zynqmp_qspi_init_hw: Initialize the hardware
* @xqspi: Pointer to the zynqmp_qspi structure
*
* The default settings of the QSPI controller's configurable parameters on
* reset are
* - Master mode
* - TX threshold set to 1
* - RX threshold set to 1
* - Flash memory interface mode enabled
* This function performs the following actions
* - Disable and clear all the interrupts
* - Enable manual slave select
* - Enable manual start
* - Deselect all the chip select lines
* - Set the little endian mode of TX FIFO and
* - Enable the QSPI controller
*/
static void zynqmp_qspi_init_hw(struct zynqmp_qspi *xqspi)
{
u32 config_reg;
/* Select the GQSPI mode */
zynqmp_gqspi_write(xqspi, GQSPI_SEL_OFST, GQSPI_SEL_MASK);
/* Clear and disable interrupts */
zynqmp_gqspi_write(xqspi, GQSPI_ISR_OFST,
zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST) |
GQSPI_ISR_WR_TO_CLR_MASK);
/* Clear the DMA STS */
zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST,
zynqmp_gqspi_read(xqspi,
GQSPI_QSPIDMA_DST_I_STS_OFST));
zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_STS_OFST,
zynqmp_gqspi_read(xqspi,
GQSPI_QSPIDMA_DST_STS_OFST) |
GQSPI_QSPIDMA_DST_STS_WTC);
zynqmp_gqspi_write(xqspi, GQSPI_IDR_OFST, GQSPI_IDR_ALL_MASK);
zynqmp_gqspi_write(xqspi,
GQSPI_QSPIDMA_DST_I_DIS_OFST,
GQSPI_QSPIDMA_DST_INTR_ALL_MASK);
/* Disable the GQSPI */
zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
/* Manual start */
config_reg |= GQSPI_CFG_GEN_FIFO_START_MODE_MASK;
/* Little endian by default */
config_reg &= ~GQSPI_CFG_ENDIAN_MASK;
/* Disable poll time out */
config_reg &= ~GQSPI_CFG_EN_POLL_TO_MASK;
/* Set hold bit */
config_reg |= GQSPI_CFG_WP_HOLD_MASK;
/* Clear pre-scalar by default */
config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
/* CPHA 0 */
config_reg &= ~GQSPI_CFG_CLK_PHA_MASK;
/* CPOL 0 */
config_reg &= ~GQSPI_CFG_CLK_POL_MASK;
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
/* Clear the TX and RX FIFO */
zynqmp_gqspi_write(xqspi, GQSPI_FIFO_CTRL_OFST,
GQSPI_FIFO_CTRL_RST_RX_FIFO_MASK |
GQSPI_FIFO_CTRL_RST_TX_FIFO_MASK |
GQSPI_FIFO_CTRL_RST_GEN_FIFO_MASK);
/* Set by default to allow for high frequencies */
zynqmp_gqspi_write(xqspi, GQSPI_LPBK_DLY_ADJ_OFST,
zynqmp_gqspi_read(xqspi, GQSPI_LPBK_DLY_ADJ_OFST) |
GQSPI_LPBK_DLY_ADJ_USE_LPBK_MASK);
/* Reset thresholds */
zynqmp_gqspi_write(xqspi, GQSPI_TX_THRESHOLD_OFST,
GQSPI_TX_FIFO_THRESHOLD_RESET_VAL);
zynqmp_gqspi_write(xqspi, GQSPI_RX_THRESHOLD_OFST,
GQSPI_RX_FIFO_THRESHOLD);
zynqmp_gqspi_write(xqspi, GQSPI_GF_THRESHOLD_OFST,
GQSPI_GEN_FIFO_THRESHOLD_RESET_VAL);
zynqmp_gqspi_selectslave(xqspi,
GQSPI_SELECT_FLASH_CS_LOWER,
GQSPI_SELECT_FLASH_BUS_LOWER);
/* Initialize DMA */
zynqmp_gqspi_write(xqspi,
GQSPI_QSPIDMA_DST_CTRL_OFST,
GQSPI_QSPIDMA_DST_CTRL_RESET_VAL);
/* Enable the GQSPI */
zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);
}
/**
* zynqmp_qspi_copy_read_data: Copy data to RX buffer
* @xqspi: Pointer to the zynqmp_qspi structure
* @data: The variable where data is stored
* @size: Number of bytes to be copied from data to RX buffer
*/
static void zynqmp_qspi_copy_read_data(struct zynqmp_qspi *xqspi,
ulong data, u8 size)
{
memcpy(xqspi->rxbuf, &data, size);
xqspi->rxbuf += size;
xqspi->bytes_to_receive -= size;
}
/**
* zynqmp_prepare_transfer_hardware: Prepares hardware for transfer.
* @master: Pointer to the spi_master structure which provides
* information about the controller.
*
* This function enables SPI master controller.
*
* Return: 0 on success; error value otherwise
*/
static int zynqmp_prepare_transfer_hardware(struct spi_master *master)
{
struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
int ret;
ret = clk_enable(xqspi->refclk);
if (ret)
goto clk_err;
ret = clk_enable(xqspi->pclk);
if (ret)
goto clk_err;
zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, GQSPI_EN_MASK);
return 0;
clk_err:
return ret;
}
/**
* zynqmp_unprepare_transfer_hardware: Relaxes hardware after transfer
* @master: Pointer to the spi_master structure which provides
* information about the controller.
*
* This function disables the SPI master controller.
*
* Return: Always 0
*/
static int zynqmp_unprepare_transfer_hardware(struct spi_master *master)
{
struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
clk_disable(xqspi->refclk);
clk_disable(xqspi->pclk);
return 0;
}
/**
* zynqmp_qspi_chipselect: Select or deselect the chip select line
* @qspi: Pointer to the spi_device structure
* @is_high: Select(0) or deselect (1) the chip select line
*/
static void zynqmp_qspi_chipselect(struct spi_device *qspi, bool is_high)
{
struct zynqmp_qspi *xqspi = spi_master_get_devdata(qspi->master);
ulong timeout;
u32 genfifoentry = 0x0, statusreg;
genfifoentry |= GQSPI_GENFIFO_MODE_SPI;
genfifoentry |= xqspi->genfifobus;
if (!is_high) {
genfifoentry |= xqspi->genfifocs;
genfifoentry |= GQSPI_GENFIFO_CS_SETUP;
} else {
genfifoentry |= GQSPI_GENFIFO_CS_HOLD;
}
zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
/* Dummy generic FIFO entry */
zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);
/* Manually start the generic FIFO command */
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
GQSPI_CFG_START_GEN_FIFO_MASK);
timeout = jiffies + msecs_to_jiffies(1000);
/* Wait until the generic FIFO command is empty */
do {
statusreg = zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST);
if ((statusreg & GQSPI_ISR_GENFIFOEMPTY_MASK) &&
(statusreg & GQSPI_ISR_TXEMPTY_MASK))
break;
else
cpu_relax();
} while (!time_after_eq(jiffies, timeout));
if (time_after_eq(jiffies, timeout))
dev_err(xqspi->dev, "Chip select timed out\n");
}
/**
* zynqmp_qspi_setup_transfer: Configure QSPI controller for specified
* transfer
* @qspi: Pointer to the spi_device structure
* @transfer: Pointer to the spi_transfer structure which provides
* information about next transfer setup parameters
*
* Sets the operational mode of QSPI controller for the next QSPI transfer and
* sets the requested clock frequency.
*
* Return: Always 0
*
* Note:
* If the requested frequency is not an exact match with what can be
* obtained using the pre-scalar value, the driver sets the clock
* frequency which is lower than the requested frequency (maximum lower)
* for the transfer.
*
* If the requested frequency is higher or lower than that is supported
* by the QSPI controller the driver will set the highest or lowest
* frequency supported by controller.
*/
static int zynqmp_qspi_setup_transfer(struct spi_device *qspi,
struct spi_transfer *transfer)
{
struct zynqmp_qspi *xqspi = spi_master_get_devdata(qspi->master);
ulong clk_rate;
u32 config_reg, req_hz, baud_rate_val = 0;
if (transfer)
req_hz = transfer->speed_hz;
else
req_hz = qspi->max_speed_hz;
/* Set the clock frequency */
/* If req_hz == 0, default to lowest speed */
clk_rate = clk_get_rate(xqspi->refclk);
while ((baud_rate_val < GQSPI_BAUD_DIV_MAX) &&
(clk_rate /
(GQSPI_BAUD_DIV_SHIFT << baud_rate_val)) > req_hz)
baud_rate_val++;
config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
/* Set the QSPI clock phase and clock polarity */
config_reg &= (~GQSPI_CFG_CLK_PHA_MASK) & (~GQSPI_CFG_CLK_POL_MASK);
if (qspi->mode & SPI_CPHA)
config_reg |= GQSPI_CFG_CLK_PHA_MASK;
if (qspi->mode & SPI_CPOL)
config_reg |= GQSPI_CFG_CLK_POL_MASK;
config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT);
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
return 0;
}
/**
* zynqmp_qspi_setup: Configure the QSPI controller
* @qspi: Pointer to the spi_device structure
*
* Sets the operational mode of QSPI controller for the next QSPI transfer,
* baud rate and divisor value to setup the requested qspi clock.
*
* Return: 0 on success; error value otherwise.
*/
static int zynqmp_qspi_setup(struct spi_device *qspi)
{
if (qspi->master->busy)
return -EBUSY;
return 0;
}
/**
* zynqmp_qspi_filltxfifo: Fills the TX FIFO as long as there is room in
* the FIFO or the bytes required to be
* transmitted.
* @xqspi: Pointer to the zynqmp_qspi structure
* @size: Number of bytes to be copied from TX buffer to TX FIFO
*/
static void zynqmp_qspi_filltxfifo(struct zynqmp_qspi *xqspi, int size)
{
u32 count = 0, intermediate;
while ((xqspi->bytes_to_transfer > 0) && (count < size)) {
memcpy(&intermediate, xqspi->txbuf, 4);
zynqmp_gqspi_write(xqspi, GQSPI_TXD_OFST, intermediate);
if (xqspi->bytes_to_transfer >= 4) {
xqspi->txbuf += 4;
xqspi->bytes_to_transfer -= 4;
} else {
xqspi->txbuf += xqspi->bytes_to_transfer;
xqspi->bytes_to_transfer = 0;
}
count++;
}
}
/**
* zynqmp_qspi_readrxfifo: Fills the RX FIFO as long as there is room in
* the FIFO.
* @xqspi: Pointer to the zynqmp_qspi structure
* @size: Number of bytes to be copied from RX buffer to RX FIFO
*/
static void zynqmp_qspi_readrxfifo(struct zynqmp_qspi *xqspi, u32 size)
{
ulong data;
int count = 0;
while ((count < size) && (xqspi->bytes_to_receive > 0)) {
if (xqspi->bytes_to_receive >= 4) {
(*(u32 *) xqspi->rxbuf) =
zynqmp_gqspi_read(xqspi, GQSPI_RXD_OFST);
xqspi->rxbuf += 4;
xqspi->bytes_to_receive -= 4;
count += 4;
} else {
data = zynqmp_gqspi_read(xqspi, GQSPI_RXD_OFST);
count += xqspi->bytes_to_receive;
zynqmp_qspi_copy_read_data(xqspi, data,
xqspi->bytes_to_receive);
xqspi->bytes_to_receive = 0;
}
}
}
/**
* zynqmp_process_dma_irq: Handler for DMA done interrupt of QSPI
* controller
* @xqspi: zynqmp_qspi instance pointer
*
* This function handles DMA interrupt only.
*/
static void zynqmp_process_dma_irq(struct zynqmp_qspi *xqspi)
{
u32 config_reg, genfifoentry;
dma_unmap_single(xqspi->dev, xqspi->dma_addr,
xqspi->dma_rx_bytes, DMA_FROM_DEVICE);
xqspi->rxbuf += xqspi->dma_rx_bytes;
xqspi->bytes_to_receive -= xqspi->dma_rx_bytes;
xqspi->dma_rx_bytes = 0;
/* Disabling the DMA interrupts */
zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_DIS_OFST,
GQSPI_QSPIDMA_DST_I_EN_DONE_MASK);
if (xqspi->bytes_to_receive > 0) {
/* Switch to IO mode,for remaining bytes to receive */
config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
/* Initiate the transfer of remaining bytes */
genfifoentry = xqspi->genfifoentry;
genfifoentry |= xqspi->bytes_to_receive;
zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
/* Dummy generic FIFO entry */
zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);
/* Manual start */
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
(zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
GQSPI_CFG_START_GEN_FIFO_MASK));
/* Enable the RX interrupts for IO mode */
zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
GQSPI_IER_GENFIFOEMPTY_MASK |
GQSPI_IER_RXNEMPTY_MASK |
GQSPI_IER_RXEMPTY_MASK);
}
}
/**
* zynqmp_qspi_irq: Interrupt service routine of the QSPI controller
* @irq: IRQ number
* @dev_id: Pointer to the xqspi structure
*
* This function handles TX empty only.
* On TX empty interrupt this function reads the received data from RX FIFO
* and fills the TX FIFO if there is any data remaining to be transferred.
*
* Return: IRQ_HANDLED when interrupt is handled
* IRQ_NONE otherwise.
*/
static irqreturn_t zynqmp_qspi_irq(int irq, void *dev_id)
{
struct spi_master *master = dev_id;
struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
int ret = IRQ_NONE;
u32 status, mask, dma_status = 0;
status = zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST);
zynqmp_gqspi_write(xqspi, GQSPI_ISR_OFST, status);
mask = (status & ~(zynqmp_gqspi_read(xqspi, GQSPI_IMASK_OFST)));
/* Read and clear DMA status */
if (xqspi->mode == GQSPI_MODE_DMA) {
dma_status =
zynqmp_gqspi_read(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST);
zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST,
dma_status);
}
if (mask & GQSPI_ISR_TXNOT_FULL_MASK) {
zynqmp_qspi_filltxfifo(xqspi, GQSPI_TX_FIFO_FILL);
ret = IRQ_HANDLED;
}
if (dma_status & GQSPI_QSPIDMA_DST_I_STS_DONE_MASK) {
zynqmp_process_dma_irq(xqspi);
ret = IRQ_HANDLED;
} else if (!(mask & GQSPI_IER_RXEMPTY_MASK) &&
(mask & GQSPI_IER_GENFIFOEMPTY_MASK)) {
zynqmp_qspi_readrxfifo(xqspi, GQSPI_RX_FIFO_FILL);
ret = IRQ_HANDLED;
}
if ((xqspi->bytes_to_receive == 0) && (xqspi->bytes_to_transfer == 0)
&& ((status & GQSPI_IRQ_MASK) == GQSPI_IRQ_MASK)) {
zynqmp_gqspi_write(xqspi, GQSPI_IDR_OFST, GQSPI_ISR_IDR_MASK);
spi_finalize_current_transfer(master);
ret = IRQ_HANDLED;
}
return ret;
}
/**
* zynqmp_qspi_selectspimode: Selects SPI mode - x1 or x2 or x4.
* @xqspi: xqspi is a pointer to the GQSPI instance
* @spimode: spimode - SPI or DUAL or QUAD.
* Return: Mask to set desired SPI mode in GENFIFO entry.
*/
static inline u32 zynqmp_qspi_selectspimode(struct zynqmp_qspi *xqspi,
u8 spimode)
{
u32 mask = 0;
switch (spimode) {
case GQSPI_SELECT_MODE_DUALSPI:
mask = GQSPI_GENFIFO_MODE_DUALSPI;
break;
case GQSPI_SELECT_MODE_QUADSPI:
mask = GQSPI_GENFIFO_MODE_QUADSPI;
break;
case GQSPI_SELECT_MODE_SPI:
mask = GQSPI_GENFIFO_MODE_SPI;
break;
default:
dev_warn(xqspi->dev, "Invalid SPI mode\n");
}
return mask;
}
/**
* zynq_qspi_setuprxdma: This function sets up the RX DMA operation
* @xqspi: xqspi is a pointer to the GQSPI instance.
*/
static void zynq_qspi_setuprxdma(struct zynqmp_qspi *xqspi)
{
u32 rx_bytes, rx_rem, config_reg;
dma_addr_t addr;
u64 dma_align = (u64)(uintptr_t)xqspi->rxbuf;
if ((xqspi->bytes_to_receive < 8) ||
((dma_align & GQSPI_DMA_UNALIGN) != 0x0)) {
/* Setting to IO mode */
config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
xqspi->mode = GQSPI_MODE_IO;
xqspi->dma_rx_bytes = 0;
return;
}
rx_rem = xqspi->bytes_to_receive % 4;
rx_bytes = (xqspi->bytes_to_receive - rx_rem);
addr = dma_map_single(xqspi->dev, (void *)xqspi->rxbuf,
rx_bytes, DMA_FROM_DEVICE);
if (dma_mapping_error(xqspi->dev, addr))
dev_err(xqspi->dev, "ERR:rxdma:memory not mapped\n");
xqspi->dma_rx_bytes = rx_bytes;
xqspi->dma_addr = addr;
zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_ADDR_OFST,
(u32)(addr & 0xffffffff));
addr = ((addr >> 16) >> 16);
zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_ADDR_MSB_OFST,
((u32)addr) & 0xfff);
/* Enabling the DMA mode */
config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
config_reg |= GQSPI_CFG_MODE_EN_DMA_MASK;
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
/* Switch to DMA mode */
xqspi->mode = GQSPI_MODE_DMA;
/* Write the number of bytes to transfer */
zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_SIZE_OFST, rx_bytes);
}
/**
* zynqmp_qspi_txrxsetup: This function checks the TX/RX buffers in
* the transfer and sets up the GENFIFO entries,
* TX FIFO as required.
* @xqspi: xqspi is a pointer to the GQSPI instance.
* @transfer: It is a pointer to the structure containing transfer data.
* @genfifoentry: genfifoentry is pointer to the variable in which
* GENFIFO mask is returned to calling function
*/
static void zynqmp_qspi_txrxsetup(struct zynqmp_qspi *xqspi,
struct spi_transfer *transfer,
u32 *genfifoentry)
{
u32 config_reg;
/* Transmit */
if ((xqspi->txbuf != NULL) && (xqspi->rxbuf == NULL)) {
/* Setup data to be TXed */
*genfifoentry &= ~GQSPI_GENFIFO_RX;
*genfifoentry |= GQSPI_GENFIFO_DATA_XFER;
*genfifoentry |= GQSPI_GENFIFO_TX;
*genfifoentry |=
zynqmp_qspi_selectspimode(xqspi, transfer->tx_nbits);
xqspi->bytes_to_transfer = transfer->len;
if (xqspi->mode == GQSPI_MODE_DMA) {
config_reg = zynqmp_gqspi_read(xqspi,
GQSPI_CONFIG_OFST);
config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
config_reg);
xqspi->mode = GQSPI_MODE_IO;
}
zynqmp_qspi_filltxfifo(xqspi, GQSPI_TXD_DEPTH);
/* Discard RX data */
xqspi->bytes_to_receive = 0;
} else if ((xqspi->txbuf == NULL) && (xqspi->rxbuf != NULL)) {
/* Receive */
/* TX auto fill */
*genfifoentry &= ~GQSPI_GENFIFO_TX;
/* Setup RX */
*genfifoentry |= GQSPI_GENFIFO_DATA_XFER;
*genfifoentry |= GQSPI_GENFIFO_RX;
*genfifoentry |=
zynqmp_qspi_selectspimode(xqspi, transfer->rx_nbits);
xqspi->bytes_to_transfer = 0;
xqspi->bytes_to_receive = transfer->len;
zynq_qspi_setuprxdma(xqspi);
}
}
/**
* zynqmp_qspi_start_transfer: Initiates the QSPI transfer
* @master: Pointer to the spi_master structure which provides
* information about the controller.
* @qspi: Pointer to the spi_device structure
* @transfer: Pointer to the spi_transfer structure which provide information
* about next transfer parameters
*
* This function fills the TX FIFO, starts the QSPI transfer, and waits for the
* transfer to be completed.
*
* Return: Number of bytes transferred in the last transfer
*/
static int zynqmp_qspi_start_transfer(struct spi_master *master,
struct spi_device *qspi,
struct spi_transfer *transfer)
{
struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
u32 genfifoentry = 0x0, transfer_len;
xqspi->txbuf = transfer->tx_buf;
xqspi->rxbuf = transfer->rx_buf;
zynqmp_qspi_setup_transfer(qspi, transfer);
genfifoentry |= xqspi->genfifocs;
genfifoentry |= xqspi->genfifobus;
zynqmp_qspi_txrxsetup(xqspi, transfer, &genfifoentry);
if (xqspi->mode == GQSPI_MODE_DMA)
transfer_len = xqspi->dma_rx_bytes;
else
transfer_len = transfer->len;
xqspi->genfifoentry = genfifoentry;
if ((transfer_len) < GQSPI_GENFIFO_IMM_DATA_MASK) {
genfifoentry &= ~GQSPI_GENFIFO_IMM_DATA_MASK;
genfifoentry |= transfer_len;
zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
} else {
int tempcount = transfer_len;
u32 exponent = 8; /* 2^8 = 256 */
u8 imm_data = tempcount & 0xFF;
tempcount &= ~(tempcount & 0xFF);
/* Immediate entry */
if (tempcount != 0) {
/* Exponent entries */
genfifoentry |= GQSPI_GENFIFO_EXP;
while (tempcount != 0) {
if (tempcount & GQSPI_GENFIFO_EXP_START) {
genfifoentry &=
~GQSPI_GENFIFO_IMM_DATA_MASK;
genfifoentry |= exponent;
zynqmp_gqspi_write(xqspi,
GQSPI_GEN_FIFO_OFST,
genfifoentry);
}
tempcount = tempcount >> 1;
exponent++;
}
}
if (imm_data != 0) {
genfifoentry &= ~GQSPI_GENFIFO_EXP;
genfifoentry &= ~GQSPI_GENFIFO_IMM_DATA_MASK;
genfifoentry |= (u8) (imm_data & 0xFF);
zynqmp_gqspi_write(xqspi,
GQSPI_GEN_FIFO_OFST, genfifoentry);
}
}
if ((xqspi->mode == GQSPI_MODE_IO) &&
(xqspi->rxbuf != NULL)) {
/* Dummy generic FIFO entry */
zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);
}
/* Since we are using manual mode */
zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
GQSPI_CFG_START_GEN_FIFO_MASK);
if (xqspi->txbuf != NULL)
/* Enable interrupts for TX */
zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
GQSPI_IER_TXEMPTY_MASK |
GQSPI_IER_GENFIFOEMPTY_MASK |
GQSPI_IER_TXNOT_FULL_MASK);
if (xqspi->rxbuf != NULL) {
/* Enable interrupts for RX */
if (xqspi->mode == GQSPI_MODE_DMA) {
/* Enable DMA interrupts */
zynqmp_gqspi_write(xqspi,
GQSPI_QSPIDMA_DST_I_EN_OFST,
GQSPI_QSPIDMA_DST_I_EN_DONE_MASK);
} else {
zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
GQSPI_IER_GENFIFOEMPTY_MASK |
GQSPI_IER_RXNEMPTY_MASK |
GQSPI_IER_RXEMPTY_MASK);
}
}
return transfer->len;
}
/**
* zynqmp_qspi_suspend: Suspend method for the QSPI driver
* @_dev: Address of the platform_device structure
*
* This function stops the QSPI driver queue and disables the QSPI controller
*
* Return: Always 0
*/
static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
{
struct platform_device *pdev = container_of(dev,
struct platform_device,
dev);
struct spi_master *master = platform_get_drvdata(pdev);
spi_master_suspend(master);
zynqmp_unprepare_transfer_hardware(master);
return 0;
}
/**
* zynqmp_qspi_resume: Resume method for the QSPI driver
* @dev: Address of the platform_device structure
*
* The function starts the QSPI driver queue and initializes the QSPI
* controller
*
* Return: 0 on success; error value otherwise
*/
static int __maybe_unused zynqmp_qspi_resume(struct device *dev)
{
struct platform_device *pdev = container_of(dev,
struct platform_device,
dev);
struct spi_master *master = platform_get_drvdata(pdev);
struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
int ret = 0;
ret = clk_enable(xqspi->pclk);
if (ret) {
dev_err(dev, "Cannot enable APB clock.\n");
return ret;
}
ret = clk_enable(xqspi->refclk);
if (ret) {
dev_err(dev, "Cannot enable device clock.\n");
clk_disable(xqspi->pclk);
return ret;
}
spi_master_resume(master);
return 0;
}
static SIMPLE_DEV_PM_OPS(zynqmp_qspi_dev_pm_ops, zynqmp_qspi_suspend,
zynqmp_qspi_resume);
/**
* zynqmp_qspi_probe: Probe method for the QSPI driver
* @pdev: Pointer to the platform_device structure
*
* This function initializes the driver data structures and the hardware.
*
* Return: 0 on success; error value otherwise
*/
static int zynqmp_qspi_probe(struct platform_device *pdev)
{
int ret = 0;
struct spi_master *master;
struct zynqmp_qspi *xqspi;
struct resource *res;
struct device *dev = &pdev->dev;
master = spi_alloc_master(&pdev->dev, sizeof(*xqspi));
if (!master)
return -ENOMEM;
xqspi = spi_master_get_devdata(master);
master->dev.of_node = pdev->dev.of_node;
platform_set_drvdata(pdev, master);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
xqspi->regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(xqspi->regs)) {
ret = PTR_ERR(xqspi->regs);
goto remove_master;
}
xqspi->dev = dev;
xqspi->pclk = devm_clk_get(&pdev->dev, "pclk");
if (IS_ERR(xqspi->pclk)) {
dev_err(dev, "pclk clock not found.\n");
ret = PTR_ERR(xqspi->pclk);
goto remove_master;
}
ret = clk_prepare_enable(xqspi->pclk);
if (ret) {
dev_err(dev, "Unable to enable APB clock.\n");
goto remove_master;
}
xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
if (IS_ERR(xqspi->refclk)) {
dev_err(dev, "ref_clk clock not found.\n");
ret = PTR_ERR(xqspi->refclk);
goto clk_dis_pclk;
}
ret = clk_prepare_enable(xqspi->refclk);
if (ret) {
dev_err(dev, "Unable to enable device clock.\n");
goto clk_dis_pclk;
}
/* QSPI controller initializations */
zynqmp_qspi_init_hw(xqspi);
xqspi->irq = platform_get_irq(pdev, 0);
if (xqspi->irq <= 0) {
ret = -ENXIO;
dev_err(dev, "irq resource not found\n");
goto clk_dis_all;
}
ret = devm_request_irq(&pdev->dev, xqspi->irq, zynqmp_qspi_irq,
0, pdev->name, master);
if (ret != 0) {
ret = -ENXIO;
dev_err(dev, "request_irq failed\n");
goto clk_dis_all;
}
master->num_chipselect = GQSPI_DEFAULT_NUM_CS;
master->setup = zynqmp_qspi_setup;
master->set_cs = zynqmp_qspi_chipselect;
master->transfer_one = zynqmp_qspi_start_transfer;
master->prepare_transfer_hardware = zynqmp_prepare_transfer_hardware;
master->unprepare_transfer_hardware =
zynqmp_unprepare_transfer_hardware;
master->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;
master->bits_per_word_mask = SPI_BPW_MASK(8);
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
SPI_TX_DUAL | SPI_TX_QUAD;
if (master->dev.parent == NULL)
master->dev.parent = &master->dev;
ret = spi_register_master(master);
if (ret)
goto clk_dis_all;
return 0;
clk_dis_all:
clk_disable_unprepare(xqspi->refclk);
clk_dis_pclk:
clk_disable_unprepare(xqspi->pclk);
remove_master:
spi_master_put(master);
return ret;
}
/**
* zynqmp_qspi_remove: Remove method for the QSPI driver
* @pdev: Pointer to the platform_device structure
*
* This function is called if a device is physically removed from the system or
* if the driver module is being unloaded. It frees all resources allocated to
* the device.
*
* Return: 0 Always
*/
static int zynqmp_qspi_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
clk_disable_unprepare(xqspi->refclk);
clk_disable_unprepare(xqspi->pclk);
spi_unregister_master(master);
return 0;
}
static const struct of_device_id zynqmp_qspi_of_match[] = {
{ .compatible = "xlnx,zynqmp-qspi-1.0", },
{ /* End of table */ }
};
MODULE_DEVICE_TABLE(of, zynqmp_qspi_of_match);
static struct platform_driver zynqmp_qspi_driver = {
.probe = zynqmp_qspi_probe,
.remove = zynqmp_qspi_remove,
.driver = {
.name = "zynqmp-qspi",
.of_match_table = zynqmp_qspi_of_match,
.pm = &zynqmp_qspi_dev_pm_ops,
},
};
module_platform_driver(zynqmp_qspi_driver);
MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx Zynqmp QSPI driver");
MODULE_LICENSE("GPL");
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