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path: root/drivers/spi/spi-cadence.c
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Diffstat (limited to 'drivers/spi/spi-cadence.c')
-rw-r--r--drivers/spi/spi-cadence.c254
1 files changed, 167 insertions, 87 deletions
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index de8fe3c5becb..47054da630d0 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
- * Cadence SPI controller driver (master and slave mode)
+ * Cadence SPI controller driver (host and target mode)
*
* Copyright (C) 2008 - 2014 Xilinx, Inc.
*
@@ -18,6 +18,7 @@
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/spi/spi.h>
/* Name of this driver */
@@ -59,10 +60,10 @@
CDNS_SPI_CR_BAUD_DIV_4)
/*
- * SPI Configuration Register - Baud rate and slave select
+ * SPI Configuration Register - Baud rate and target select
*
* These are the values used in the calculation of baud rate divisor and
- * setting the slave select.
+ * setting the target select.
*/
#define CDNS_SPI_BAUD_DIV_MAX 7 /* Baud rate divisor maximum */
@@ -108,9 +109,11 @@
* @rxbuf: Pointer to the RX buffer
* @tx_bytes: Number of bytes left to transfer
* @rx_bytes: Number of bytes requested
+ * @n_bytes: Number of bytes per word
* @dev_busy: Device busy flag
* @is_decoded_cs: Flag for decoder property set or not
* @tx_fifo_depth: Depth of the TX FIFO
+ * @rstc: Optional reset control for SPI controller
*/
struct cdns_spi {
void __iomem *regs;
@@ -118,13 +121,22 @@ struct cdns_spi {
struct clk *pclk;
unsigned int clk_rate;
u32 speed_hz;
- const u8 *txbuf;
- u8 *rxbuf;
+ const void *txbuf;
+ void *rxbuf;
int tx_bytes;
int rx_bytes;
+ u8 n_bytes;
u8 dev_busy;
u32 is_decoded_cs;
unsigned int tx_fifo_depth;
+ struct reset_control *rstc;
+};
+
+enum cdns_spi_frame_n_bytes {
+ CDNS_SPI_N_BYTES_NULL = 0,
+ CDNS_SPI_N_BYTES_U8 = 1,
+ CDNS_SPI_N_BYTES_U16 = 2,
+ CDNS_SPI_N_BYTES_U32 = 4
};
/* Macros for the SPI controller read/write */
@@ -141,20 +153,20 @@ static inline void cdns_spi_write(struct cdns_spi *xspi, u32 offset, u32 val)
/**
* cdns_spi_init_hw - Initialize the hardware and configure the SPI controller
* @xspi: Pointer to the cdns_spi structure
- * @is_slave: Flag to indicate slave or master mode
- * * On reset the SPI controller is configured to slave or master mode.
- * In master mode baud rate divisor is set to 4, threshold value for TX FIFO
+ * @is_target: Flag to indicate target or host mode
+ * * On reset the SPI controller is configured to target or host mode.
+ * In host mode baud rate divisor is set to 4, threshold value for TX FIFO
* not full interrupt is set to 1 and size of the word to be transferred as 8 bit.
*
* This function initializes the SPI controller to disable and clear all the
- * interrupts, enable manual slave select and manual start, deselect all the
+ * interrupts, enable manual target select and manual start, deselect all the
* chip select lines, and enable the SPI controller.
*/
-static void cdns_spi_init_hw(struct cdns_spi *xspi, bool is_slave)
+static void cdns_spi_init_hw(struct cdns_spi *xspi, bool is_target)
{
u32 ctrl_reg = 0;
- if (!is_slave)
+ if (!is_target)
ctrl_reg |= CDNS_SPI_CR_DEFAULT;
if (xspi->is_decoded_cs)
@@ -185,10 +197,10 @@ static void cdns_spi_chipselect(struct spi_device *spi, bool is_high)
ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR);
if (is_high) {
- /* Deselect the slave */
+ /* Deselect the target */
ctrl_reg |= CDNS_SPI_CR_SSCTRL;
} else {
- /* Select the slave */
+ /* Select the target */
ctrl_reg &= ~CDNS_SPI_CR_SSCTRL;
if (!(xspi->is_decoded_cs))
ctrl_reg |= ((~(CDNS_SPI_SS0 << spi_get_chipselect(spi, 0))) <<
@@ -227,7 +239,7 @@ static void cdns_spi_config_clock_mode(struct spi_device *spi)
/*
* Just writing the CR register does not seem to apply the clock
* setting changes. This is problematic when changing the clock
- * polarity as it will cause the SPI slave to see spurious clock
+ * polarity as it will cause the SPI target to see spurious clock
* transitions. To workaround the issue toggle the ER register.
*/
cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE);
@@ -302,6 +314,78 @@ static int cdns_spi_setup_transfer(struct spi_device *spi,
return 0;
}
+static u8 cdns_spi_n_bytes(struct spi_transfer *transfer)
+{
+ if (transfer->bits_per_word <= 8)
+ return CDNS_SPI_N_BYTES_U8;
+ else if (transfer->bits_per_word <= 16)
+ return CDNS_SPI_N_BYTES_U16;
+ else
+ return CDNS_SPI_N_BYTES_U32;
+}
+
+static inline void cdns_spi_reader(struct cdns_spi *xspi)
+{
+ u32 rxw = 0;
+
+ if (xspi->rxbuf && !IS_ALIGNED((uintptr_t)xspi->rxbuf, xspi->n_bytes)) {
+ pr_err("%s: rxbuf address is not aligned for %d bytes\n",
+ __func__, xspi->n_bytes);
+ return;
+ }
+
+ rxw = cdns_spi_read(xspi, CDNS_SPI_RXD);
+ if (xspi->rxbuf) {
+ switch (xspi->n_bytes) {
+ case CDNS_SPI_N_BYTES_U8:
+ *(u8 *)xspi->rxbuf = rxw;
+ break;
+ case CDNS_SPI_N_BYTES_U16:
+ *(u16 *)xspi->rxbuf = rxw;
+ break;
+ case CDNS_SPI_N_BYTES_U32:
+ *(u32 *)xspi->rxbuf = rxw;
+ break;
+ default:
+ pr_err("%s invalid n_bytes %d\n", __func__,
+ xspi->n_bytes);
+ return;
+ }
+ xspi->rxbuf = (u8 *)xspi->rxbuf + xspi->n_bytes;
+ }
+}
+
+static inline void cdns_spi_writer(struct cdns_spi *xspi)
+{
+ u32 txw = 0;
+
+ if (xspi->txbuf && !IS_ALIGNED((uintptr_t)xspi->txbuf, xspi->n_bytes)) {
+ pr_err("%s: txbuf address is not aligned for %d bytes\n",
+ __func__, xspi->n_bytes);
+ return;
+ }
+
+ if (xspi->txbuf) {
+ switch (xspi->n_bytes) {
+ case CDNS_SPI_N_BYTES_U8:
+ txw = *(u8 *)xspi->txbuf;
+ break;
+ case CDNS_SPI_N_BYTES_U16:
+ txw = *(u16 *)xspi->txbuf;
+ break;
+ case CDNS_SPI_N_BYTES_U32:
+ txw = *(u32 *)xspi->txbuf;
+ break;
+ default:
+ pr_err("%s invalid n_bytes %d\n", __func__,
+ xspi->n_bytes);
+ return;
+ }
+ cdns_spi_write(xspi, CDNS_SPI_TXD, txw);
+ xspi->txbuf = (u8 *)xspi->txbuf + xspi->n_bytes;
+ }
+}
+
/**
* cdns_spi_process_fifo - Fills the TX FIFO, and drain the RX FIFO
* @xspi: Pointer to the cdns_spi structure
@@ -317,29 +401,15 @@ static void cdns_spi_process_fifo(struct cdns_spi *xspi, int ntx, int nrx)
xspi->rx_bytes -= nrx;
while (ntx || nrx) {
- /* When xspi in busy condition, bytes may send failed,
- * then spi control did't work thoroughly, add one byte delay
- */
- if (cdns_spi_read(xspi, CDNS_SPI_ISR) & CDNS_SPI_IXR_TXFULL)
- udelay(10);
+ if (nrx) {
+ cdns_spi_reader(xspi);
+ nrx--;
+ }
if (ntx) {
- if (xspi->txbuf)
- cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++);
- else
- cdns_spi_write(xspi, CDNS_SPI_TXD, 0);
-
+ cdns_spi_writer(xspi);
ntx--;
}
-
- if (nrx) {
- u8 data = cdns_spi_read(xspi, CDNS_SPI_RXD);
-
- if (xspi->rxbuf)
- *xspi->rxbuf++ = data;
-
- nrx--;
- }
}
}
@@ -392,6 +462,11 @@ static irqreturn_t cdns_spi_irq(int irq, void *dev_id)
if (xspi->tx_bytes) {
cdns_spi_process_fifo(xspi, trans_cnt, trans_cnt);
} else {
+ /* Fixed delay due to controller limitation with
+ * RX_NEMPTY incorrect status
+ * Xilinx AR:65885 contains more details
+ */
+ udelay(10);
cdns_spi_process_fifo(xspi, 0, trans_cnt);
cdns_spi_write(xspi, CDNS_SPI_IDR,
CDNS_SPI_IXR_DEFAULT);
@@ -406,7 +481,7 @@ static irqreturn_t cdns_spi_irq(int irq, void *dev_id)
static int cdns_prepare_message(struct spi_controller *ctlr,
struct spi_message *msg)
{
- if (!spi_controller_is_slave(ctlr))
+ if (!spi_controller_is_target(ctlr))
cdns_spi_config_clock_mode(msg->spi);
return 0;
}
@@ -418,9 +493,9 @@ static int cdns_prepare_message(struct spi_controller *ctlr,
* @transfer: Pointer to the spi_transfer structure which provides
* information about next transfer parameters
*
- * This function in master mode fills the TX FIFO, starts the SPI transfer and
+ * This function in host mode fills the TX FIFO, starts the SPI transfer and
* returns a positive transfer count so that core will wait for completion.
- * This function in slave mode fills the TX FIFO and wait for transfer trigger.
+ * This function in target mode fills the TX FIFO and wait for transfer trigger.
*
* Return: Number of bytes transferred in the last transfer
*/
@@ -435,18 +510,27 @@ static int cdns_transfer_one(struct spi_controller *ctlr,
xspi->tx_bytes = transfer->len;
xspi->rx_bytes = transfer->len;
- if (!spi_controller_is_slave(ctlr)) {
+ if (!spi_controller_is_target(ctlr)) {
cdns_spi_setup_transfer(spi, transfer);
} else {
/* Set TX empty threshold to half of FIFO depth
- * only if TX bytes are more than half FIFO depth.
+ * only if TX bytes are more than FIFO depth.
*/
if (xspi->tx_bytes > xspi->tx_fifo_depth)
cdns_spi_write(xspi, CDNS_SPI_THLD, xspi->tx_fifo_depth >> 1);
}
+ /* When xspi in busy condition, bytes may send failed,
+ * then spi control didn't work thoroughly, add one byte delay
+ */
+ if (cdns_spi_read(xspi, CDNS_SPI_ISR) & CDNS_SPI_IXR_TXFULL)
+ udelay(10);
+
+ xspi->n_bytes = cdns_spi_n_bytes(transfer);
+ xspi->tx_bytes = DIV_ROUND_UP(xspi->tx_bytes, xspi->n_bytes);
+ xspi->rx_bytes = DIV_ROUND_UP(xspi->rx_bytes, xspi->n_bytes);
+
cdns_spi_process_fifo(xspi, xspi->tx_fifo_depth, 0);
- spi_transfer_delay_exec(transfer);
cdns_spi_write(xspi, CDNS_SPI_IER, CDNS_SPI_IXR_DEFAULT);
return transfer->len;
@@ -457,7 +541,7 @@ static int cdns_transfer_one(struct spi_controller *ctlr,
* @ctlr: Pointer to the spi_controller structure which provides
* information about the controller.
*
- * This function enables SPI master controller.
+ * This function enables SPI host controller.
*
* Return: 0 always
*/
@@ -475,7 +559,7 @@ static int cdns_prepare_transfer_hardware(struct spi_controller *ctlr)
* @ctlr: Pointer to the spi_controller structure which provides
* information about the controller.
*
- * This function disables the SPI master controller when no slave selected.
+ * This function disables the SPI host controller when no target selected.
* This function flush out if any pending data in FIFO.
*
* Return: 0 always
@@ -486,15 +570,15 @@ static int cdns_unprepare_transfer_hardware(struct spi_controller *ctlr)
u32 ctrl_reg;
unsigned int cnt = xspi->tx_fifo_depth;
- if (spi_controller_is_slave(ctlr)) {
+ if (spi_controller_is_target(ctlr)) {
while (cnt--)
cdns_spi_read(xspi, CDNS_SPI_RXD);
}
- /* Disable the SPI if slave is deselected */
+ /* Disable the SPI if target is deselected */
ctrl_reg = cdns_spi_read(xspi, CDNS_SPI_CR);
ctrl_reg = (ctrl_reg & CDNS_SPI_CR_SSCTRL) >> CDNS_SPI_SS_SHIFT;
- if (ctrl_reg == CDNS_SPI_NOSS || spi_controller_is_slave(ctlr))
+ if (ctrl_reg == CDNS_SPI_NOSS || spi_controller_is_target(ctlr))
cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE);
/* Reset to default */
@@ -521,14 +605,14 @@ static void cdns_spi_detect_fifo_depth(struct cdns_spi *xspi)
}
/**
- * cdns_slave_abort - Abort slave transfer
+ * cdns_target_abort - Abort target transfer
* @ctlr: Pointer to the spi_controller structure
*
- * This function abort slave transfer if there any transfer timeout.
+ * This function abort target transfer if there any transfer timeout.
*
* Return: 0 always
*/
-static int cdns_slave_abort(struct spi_controller *ctlr)
+static int cdns_target_abort(struct spi_controller *ctlr)
{
struct cdns_spi *xspi = spi_controller_get_devdata(ctlr);
u32 intr_status;
@@ -555,13 +639,13 @@ static int cdns_spi_probe(struct platform_device *pdev)
struct spi_controller *ctlr;
struct cdns_spi *xspi;
u32 num_cs;
- bool slave;
+ bool target;
- slave = of_property_read_bool(pdev->dev.of_node, "spi-slave");
- if (slave)
- ctlr = spi_alloc_slave(&pdev->dev, sizeof(*xspi));
+ target = of_property_read_bool(pdev->dev.of_node, "spi-slave");
+ if (target)
+ ctlr = spi_alloc_target(&pdev->dev, sizeof(*xspi));
else
- ctlr = spi_alloc_master(&pdev->dev, sizeof(*xspi));
+ ctlr = spi_alloc_host(&pdev->dev, sizeof(*xspi));
if (!ctlr)
return -ENOMEM;
@@ -576,33 +660,31 @@ static int cdns_spi_probe(struct platform_device *pdev)
goto remove_ctlr;
}
- xspi->pclk = devm_clk_get(&pdev->dev, "pclk");
+ xspi->pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
if (IS_ERR(xspi->pclk)) {
dev_err(&pdev->dev, "pclk clock not found.\n");
ret = PTR_ERR(xspi->pclk);
goto remove_ctlr;
}
- ret = clk_prepare_enable(xspi->pclk);
- if (ret) {
- dev_err(&pdev->dev, "Unable to enable APB clock.\n");
+ xspi->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
+ if (IS_ERR(xspi->rstc)) {
+ ret = dev_err_probe(&pdev->dev, PTR_ERR(xspi->rstc),
+ "Cannot get SPI reset.\n");
goto remove_ctlr;
}
- if (!spi_controller_is_slave(ctlr)) {
- xspi->ref_clk = devm_clk_get(&pdev->dev, "ref_clk");
- if (IS_ERR(xspi->ref_clk)) {
- dev_err(&pdev->dev, "ref_clk clock not found.\n");
- ret = PTR_ERR(xspi->ref_clk);
- goto clk_dis_apb;
- }
+ reset_control_assert(xspi->rstc);
+ reset_control_deassert(xspi->rstc);
- ret = clk_prepare_enable(xspi->ref_clk);
- if (ret) {
- dev_err(&pdev->dev, "Unable to enable device clock.\n");
- goto clk_dis_apb;
- }
+ xspi->ref_clk = devm_clk_get_enabled(&pdev->dev, "ref_clk");
+ if (IS_ERR(xspi->ref_clk)) {
+ dev_err(&pdev->dev, "ref_clk clock not found.\n");
+ ret = PTR_ERR(xspi->ref_clk);
+ goto remove_ctlr;
+ }
+ if (!spi_controller_is_target(ctlr)) {
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
pm_runtime_get_noresume(&pdev->dev);
@@ -624,11 +706,11 @@ static int cdns_spi_probe(struct platform_device *pdev)
cdns_spi_detect_fifo_depth(xspi);
/* SPI controller initializations */
- cdns_spi_init_hw(xspi, spi_controller_is_slave(ctlr));
+ cdns_spi_init_hw(xspi, spi_controller_is_target(ctlr));
irq = platform_get_irq(pdev, 0);
- if (irq <= 0) {
- ret = -ENXIO;
+ if (irq < 0) {
+ ret = irq;
goto clk_dis_all;
}
@@ -648,7 +730,10 @@ static int cdns_spi_probe(struct platform_device *pdev)
ctlr->mode_bits = SPI_CPOL | SPI_CPHA;
ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
- if (!spi_controller_is_slave(ctlr)) {
+ if (of_device_is_compatible(pdev->dev.of_node, "cix,sky1-spi-r1p6"))
+ ctlr->bits_per_word_mask |= SPI_BPW_MASK(16) | SPI_BPW_MASK(32);
+
+ if (!spi_controller_is_target(ctlr)) {
ctlr->mode_bits |= SPI_CS_HIGH;
ctlr->set_cs = cdns_spi_chipselect;
ctlr->auto_runtime_pm = true;
@@ -656,11 +741,10 @@ static int cdns_spi_probe(struct platform_device *pdev)
/* Set to default valid value */
ctlr->max_speed_hz = xspi->clk_rate / 4;
xspi->speed_hz = ctlr->max_speed_hz;
- pm_runtime_mark_last_busy(&pdev->dev);
pm_runtime_put_autosuspend(&pdev->dev);
} else {
ctlr->mode_bits |= SPI_NO_CS;
- ctlr->slave_abort = cdns_slave_abort;
+ ctlr->target_abort = cdns_target_abort;
}
ret = spi_register_controller(ctlr);
if (ret) {
@@ -671,13 +755,10 @@ static int cdns_spi_probe(struct platform_device *pdev)
return ret;
clk_dis_all:
- if (!spi_controller_is_slave(ctlr)) {
- pm_runtime_set_suspended(&pdev->dev);
+ if (!spi_controller_is_target(ctlr)) {
pm_runtime_disable(&pdev->dev);
- clk_disable_unprepare(xspi->ref_clk);
+ pm_runtime_set_suspended(&pdev->dev);
}
-clk_dis_apb:
- clk_disable_unprepare(xspi->pclk);
remove_ctlr:
spi_controller_put(ctlr);
return ret;
@@ -690,8 +771,6 @@ remove_ctlr:
* 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 on success and error value on error
*/
static void cdns_spi_remove(struct platform_device *pdev)
{
@@ -700,10 +779,10 @@ static void cdns_spi_remove(struct platform_device *pdev)
cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE);
- clk_disable_unprepare(xspi->ref_clk);
- clk_disable_unprepare(xspi->pclk);
- pm_runtime_set_suspended(&pdev->dev);
- pm_runtime_disable(&pdev->dev);
+ if (!spi_controller_is_target(ctlr)) {
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ }
spi_unregister_controller(ctlr);
}
@@ -737,7 +816,7 @@ static int __maybe_unused cdns_spi_resume(struct device *dev)
struct spi_controller *ctlr = dev_get_drvdata(dev);
struct cdns_spi *xspi = spi_controller_get_devdata(ctlr);
- cdns_spi_init_hw(xspi, spi_controller_is_slave(ctlr));
+ cdns_spi_init_hw(xspi, spi_controller_is_target(ctlr));
return spi_controller_resume(ctlr);
}
@@ -797,6 +876,7 @@ static const struct dev_pm_ops cdns_spi_dev_pm_ops = {
static const struct of_device_id cdns_spi_of_match[] = {
{ .compatible = "xlnx,zynq-spi-r1p6" },
+ { .compatible = "cix,sky1-spi-r1p6" },
{ .compatible = "cdns,spi-r1p6" },
{ /* end of table */ }
};
@@ -805,7 +885,7 @@ MODULE_DEVICE_TABLE(of, cdns_spi_of_match);
/* cdns_spi_driver - This structure defines the SPI subsystem platform driver */
static struct platform_driver cdns_spi_driver = {
.probe = cdns_spi_probe,
- .remove_new = cdns_spi_remove,
+ .remove = cdns_spi_remove,
.driver = {
.name = CDNS_SPI_NAME,
.of_match_table = cdns_spi_of_match,
generated by cgit (git 2.34.1) at 2025-12-25 02:10:39 +0000