Applied "spi: Add Meson SPICC driver" to the spi tree
Mark Brown
broonie at kernel.org
Wed May 24 10:42:34 PDT 2017
The patch
spi: Add Meson SPICC driver
has been applied to the spi tree at
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git
All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying
to this mail.
Thanks,
Mark
>From 454fa271bc4e71090ef55087027c3f8701fadc5b Mon Sep 17 00:00:00 2001
From: Neil Armstrong <narmstrong at baylibre.com>
Date: Tue, 23 May 2017 15:39:33 +0200
Subject: [PATCH] spi: Add Meson SPICC driver
The SPICC hardware block on the Amlogic SoCs is Communication oriented and
can do Full-Duplex 8- to 32-bit width SPI transfers up to 30MHz.
The current driver only supportd the PIO transfer mode since the DMA seems
broken on available hardware.
Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
Signed-off-by: Mark Brown <broonie at kernel.org>
---
drivers/spi/Kconfig | 7 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-meson-spicc.c | 619 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 627 insertions(+)
create mode 100644 drivers/spi/spi-meson-spicc.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 1761c9004fc1..1dcb14ce6f38 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -393,6 +393,13 @@ config SPI_FSL_ESPI
From MPC8536, 85xx platform uses the controller, and all P10xx,
P20xx, P30xx,P40xx, P50xx uses this controller.
+config SPI_MESON_SPICC
+ tristate "Amlogic Meson SPICC controller"
+ depends on ARCH_MESON || COMPILE_TEST
+ help
+ This enables master mode support for the SPICC (SPI communication
+ controller) available in Amlogic Meson SoCs.
+
config SPI_MESON_SPIFC
tristate "Amlogic Meson SPIFC controller"
depends on ARCH_MESON || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index b375a7a89216..0d8c95e66a9b 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_SPI_LANTIQ_SSC) += spi-lantiq-ssc.o
obj-$(CONFIG_SPI_JCORE) += spi-jcore.o
obj-$(CONFIG_SPI_LM70_LLP) += spi-lm70llp.o
obj-$(CONFIG_SPI_LP8841_RTC) += spi-lp8841-rtc.o
+obj-$(CONFIG_SPI_MESON_SPICC) += spi-meson-spicc.o
obj-$(CONFIG_SPI_MESON_SPIFC) += spi-meson-spifc.o
obj-$(CONFIG_SPI_MPC512x_PSC) += spi-mpc512x-psc.o
obj-$(CONFIG_SPI_MPC52xx_PSC) += spi-mpc52xx-psc.o
diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c
new file mode 100644
index 000000000000..7f8429635502
--- /dev/null
+++ b/drivers/spi/spi-meson-spicc.c
@@ -0,0 +1,619 @@
+/*
+ * Driver for Amlogic Meson SPI communication controller (SPICC)
+ *
+ * Copyright (C) BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong at baylibre.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/reset.h>
+#include <linux/gpio.h>
+
+/*
+ * The Meson SPICC controller could support DMA based transfers, but is not
+ * implemented by the vendor code, and while having the registers documentation
+ * it has never worked on the GXL Hardware.
+ * The PIO mode is the only mode implemented, and due to badly designed HW :
+ * - all transfers are cutted in 16 words burst because the FIFO hangs on
+ * TX underflow, and there is no TX "Half-Empty" interrupt, so we go by
+ * FIFO max size chunk only
+ * - CS management is dumb, and goes UP between every burst, so is really a
+ * "Data Valid" signal than a Chip Select, GPIO link should be used instead
+ * to have a CS go down over the full transfer
+ */
+
+#define SPICC_MAX_FREQ 30000000
+#define SPICC_MAX_BURST 128
+
+/* Register Map */
+#define SPICC_RXDATA 0x00
+
+#define SPICC_TXDATA 0x04
+
+#define SPICC_CONREG 0x08
+#define SPICC_ENABLE BIT(0)
+#define SPICC_MODE_MASTER BIT(1)
+#define SPICC_XCH BIT(2)
+#define SPICC_SMC BIT(3)
+#define SPICC_POL BIT(4)
+#define SPICC_PHA BIT(5)
+#define SPICC_SSCTL BIT(6)
+#define SPICC_SSPOL BIT(7)
+#define SPICC_DRCTL_MASK GENMASK(9, 8)
+#define SPICC_DRCTL_IGNORE 0
+#define SPICC_DRCTL_FALLING 1
+#define SPICC_DRCTL_LOWLEVEL 2
+#define SPICC_CS_MASK GENMASK(13, 12)
+#define SPICC_DATARATE_MASK GENMASK(18, 16)
+#define SPICC_DATARATE_DIV4 0
+#define SPICC_DATARATE_DIV8 1
+#define SPICC_DATARATE_DIV16 2
+#define SPICC_DATARATE_DIV32 3
+#define SPICC_BITLENGTH_MASK GENMASK(24, 19)
+#define SPICC_BURSTLENGTH_MASK GENMASK(31, 25)
+
+#define SPICC_INTREG 0x0c
+#define SPICC_TE_EN BIT(0) /* TX FIFO Empty Interrupt */
+#define SPICC_TH_EN BIT(1) /* TX FIFO Half-Full Interrupt */
+#define SPICC_TF_EN BIT(2) /* TX FIFO Full Interrupt */
+#define SPICC_RR_EN BIT(3) /* RX FIFO Ready Interrupt */
+#define SPICC_RH_EN BIT(4) /* RX FIFO Half-Full Interrupt */
+#define SPICC_RF_EN BIT(5) /* RX FIFO Full Interrupt */
+#define SPICC_RO_EN BIT(6) /* RX FIFO Overflow Interrupt */
+#define SPICC_TC_EN BIT(7) /* Transfert Complete Interrupt */
+
+#define SPICC_DMAREG 0x10
+#define SPICC_DMA_ENABLE BIT(0)
+#define SPICC_TXFIFO_THRESHOLD_MASK GENMASK(5, 1)
+#define SPICC_RXFIFO_THRESHOLD_MASK GENMASK(10, 6)
+#define SPICC_READ_BURST_MASK GENMASK(14, 11)
+#define SPICC_WRITE_BURST_MASK GENMASK(18, 15)
+#define SPICC_DMA_URGENT BIT(19)
+#define SPICC_DMA_THREADID_MASK GENMASK(25, 20)
+#define SPICC_DMA_BURSTNUM_MASK GENMASK(31, 26)
+
+#define SPICC_STATREG 0x14
+#define SPICC_TE BIT(0) /* TX FIFO Empty Interrupt */
+#define SPICC_TH BIT(1) /* TX FIFO Half-Full Interrupt */
+#define SPICC_TF BIT(2) /* TX FIFO Full Interrupt */
+#define SPICC_RR BIT(3) /* RX FIFO Ready Interrupt */
+#define SPICC_RH BIT(4) /* RX FIFO Half-Full Interrupt */
+#define SPICC_RF BIT(5) /* RX FIFO Full Interrupt */
+#define SPICC_RO BIT(6) /* RX FIFO Overflow Interrupt */
+#define SPICC_TC BIT(7) /* Transfert Complete Interrupt */
+
+#define SPICC_PERIODREG 0x18
+#define SPICC_PERIOD GENMASK(14, 0) /* Wait cycles */
+
+#define SPICC_TESTREG 0x1c
+#define SPICC_TXCNT_MASK GENMASK(4, 0) /* TX FIFO Counter */
+#define SPICC_RXCNT_MASK GENMASK(9, 5) /* RX FIFO Counter */
+#define SPICC_SMSTATUS_MASK GENMASK(12, 10) /* State Machine Status */
+#define SPICC_LBC_RO BIT(13) /* Loop Back Control Read-Only */
+#define SPICC_LBC_W1 BIT(14) /* Loop Back Control Write-Only */
+#define SPICC_SWAP_RO BIT(14) /* RX FIFO Data Swap Read-Only */
+#define SPICC_SWAP_W1 BIT(15) /* RX FIFO Data Swap Write-Only */
+#define SPICC_DLYCTL_RO_MASK GENMASK(20, 15) /* Delay Control Read-Only */
+#define SPICC_DLYCTL_W1_MASK GENMASK(21, 16) /* Delay Control Write-Only */
+#define SPICC_FIFORST_RO_MASK GENMASK(22, 21) /* FIFO Softreset Read-Only */
+#define SPICC_FIFORST_W1_MASK GENMASK(23, 22) /* FIFO Softreset Write-Only */
+
+#define SPICC_DRADDR 0x20 /* Read Address of DMA */
+
+#define SPICC_DWADDR 0x24 /* Write Address of DMA */
+
+#define writel_bits_relaxed(mask, val, addr) \
+ writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr)
+
+#define SPICC_BURST_MAX 16
+#define SPICC_FIFO_HALF 10
+
+struct meson_spicc_device {
+ struct spi_master *master;
+ struct platform_device *pdev;
+ void __iomem *base;
+ struct clk *core;
+ struct spi_message *message;
+ struct spi_transfer *xfer;
+ u8 *tx_buf;
+ u8 *rx_buf;
+ unsigned int bytes_per_word;
+ unsigned long tx_remain;
+ unsigned long txb_remain;
+ unsigned long rx_remain;
+ unsigned long rxb_remain;
+ unsigned long xfer_remain;
+ bool is_burst_end;
+ bool is_last_burst;
+};
+
+static inline bool meson_spicc_txfull(struct meson_spicc_device *spicc)
+{
+ return !!FIELD_GET(SPICC_TF,
+ readl_relaxed(spicc->base + SPICC_STATREG));
+}
+
+static inline bool meson_spicc_rxready(struct meson_spicc_device *spicc)
+{
+ return FIELD_GET(SPICC_RH | SPICC_RR | SPICC_RF_EN,
+ readl_relaxed(spicc->base + SPICC_STATREG));
+}
+
+static inline u32 meson_spicc_pull_data(struct meson_spicc_device *spicc)
+{
+ unsigned int bytes = spicc->bytes_per_word;
+ unsigned int byte_shift = 0;
+ u32 data = 0;
+ u8 byte;
+
+ while (bytes--) {
+ byte = *spicc->tx_buf++;
+ data |= (byte & 0xff) << byte_shift;
+ byte_shift += 8;
+ }
+
+ spicc->tx_remain--;
+ return data;
+}
+
+static inline void meson_spicc_push_data(struct meson_spicc_device *spicc,
+ u32 data)
+{
+ unsigned int bytes = spicc->bytes_per_word;
+ unsigned int byte_shift = 0;
+ u8 byte;
+
+ while (bytes--) {
+ byte = (data >> byte_shift) & 0xff;
+ *spicc->rx_buf++ = byte;
+ byte_shift += 8;
+ }
+
+ spicc->rx_remain--;
+}
+
+static inline void meson_spicc_rx(struct meson_spicc_device *spicc)
+{
+ /* Empty RX FIFO */
+ while (spicc->rx_remain &&
+ meson_spicc_rxready(spicc))
+ meson_spicc_push_data(spicc,
+ readl_relaxed(spicc->base + SPICC_RXDATA));
+}
+
+static inline void meson_spicc_tx(struct meson_spicc_device *spicc)
+{
+ /* Fill Up TX FIFO */
+ while (spicc->tx_remain &&
+ !meson_spicc_txfull(spicc))
+ writel_relaxed(meson_spicc_pull_data(spicc),
+ spicc->base + SPICC_TXDATA);
+}
+
+static inline u32 meson_spicc_setup_rx_irq(struct meson_spicc_device *spicc,
+ u32 irq_ctrl)
+{
+ if (spicc->rx_remain > SPICC_FIFO_HALF)
+ irq_ctrl |= SPICC_RH_EN;
+ else
+ irq_ctrl |= SPICC_RR_EN;
+
+ return irq_ctrl;
+}
+
+static inline void meson_spicc_setup_burst(struct meson_spicc_device *spicc,
+ unsigned int burst_len)
+{
+ /* Setup Xfer variables */
+ spicc->tx_remain = burst_len;
+ spicc->rx_remain = burst_len;
+ spicc->xfer_remain -= burst_len * spicc->bytes_per_word;
+ spicc->is_burst_end = false;
+ if (burst_len < SPICC_BURST_MAX || !spicc->xfer_remain)
+ spicc->is_last_burst = true;
+ else
+ spicc->is_last_burst = false;
+
+ /* Setup burst length */
+ writel_bits_relaxed(SPICC_BURSTLENGTH_MASK,
+ FIELD_PREP(SPICC_BURSTLENGTH_MASK,
+ burst_len),
+ spicc->base + SPICC_CONREG);
+
+ /* Fill TX FIFO */
+ meson_spicc_tx(spicc);
+}
+
+static irqreturn_t meson_spicc_irq(int irq, void *data)
+{
+ struct meson_spicc_device *spicc = (void *) data;
+ u32 ctrl = readl_relaxed(spicc->base + SPICC_INTREG);
+ u32 stat = readl_relaxed(spicc->base + SPICC_STATREG) & ctrl;
+
+ ctrl &= ~(SPICC_RH_EN | SPICC_RR_EN);
+
+ /* Empty RX FIFO */
+ meson_spicc_rx(spicc);
+
+ /* Enable TC interrupt since we transferred everything */
+ if (!spicc->tx_remain && !spicc->rx_remain) {
+ spicc->is_burst_end = true;
+
+ /* Enable TC interrupt */
+ ctrl |= SPICC_TC_EN;
+
+ /* Reload IRQ status */
+ stat = readl_relaxed(spicc->base + SPICC_STATREG) & ctrl;
+ }
+
+ /* Check transfer complete */
+ if ((stat & SPICC_TC) && spicc->is_burst_end) {
+ unsigned int burst_len;
+
+ /* Clear TC bit */
+ writel_relaxed(SPICC_TC, spicc->base + SPICC_STATREG);
+
+ /* Disable TC interrupt */
+ ctrl &= ~SPICC_TC_EN;
+
+ if (spicc->is_last_burst) {
+ /* Disable all IRQs */
+ writel(0, spicc->base + SPICC_INTREG);
+
+ spi_finalize_current_transfer(spicc->master);
+
+ return IRQ_HANDLED;
+ }
+
+ burst_len = min_t(unsigned int,
+ spicc->xfer_remain / spicc->bytes_per_word,
+ SPICC_BURST_MAX);
+
+ /* Setup burst */
+ meson_spicc_setup_burst(spicc, burst_len);
+
+ /* Restart burst */
+ writel_bits_relaxed(SPICC_XCH, SPICC_XCH,
+ spicc->base + SPICC_CONREG);
+ }
+
+ /* Setup RX interrupt trigger */
+ ctrl = meson_spicc_setup_rx_irq(spicc, ctrl);
+
+ /* Reconfigure interrupts */
+ writel(ctrl, spicc->base + SPICC_INTREG);
+
+ return IRQ_HANDLED;
+}
+
+static u32 meson_spicc_setup_speed(struct meson_spicc_device *spicc, u32 conf,
+ u32 speed)
+{
+ unsigned long parent, value;
+ unsigned int i, div;
+
+ parent = clk_get_rate(spicc->core);
+
+ /* Find closest inferior/equal possible speed */
+ for (i = 0 ; i < 7 ; ++i) {
+ /* 2^(data_rate+2) */
+ value = parent >> (i + 2);
+
+ if (value <= speed)
+ break;
+ }
+
+ /* If provided speed it lower than max divider, use max divider */
+ if (i > 7) {
+ div = 7;
+ dev_warn_once(&spicc->pdev->dev, "unable to get close to speed %u\n",
+ speed);
+ } else
+ div = i;
+
+ dev_dbg(&spicc->pdev->dev, "parent %lu, speed %u -> %lu (%u)\n",
+ parent, speed, value, div);
+
+ conf &= ~SPICC_DATARATE_MASK;
+ conf |= FIELD_PREP(SPICC_DATARATE_MASK, div);
+
+ return conf;
+}
+
+static void meson_spicc_setup_xfer(struct meson_spicc_device *spicc,
+ struct spi_transfer *xfer)
+{
+ u32 conf, conf_orig;
+
+ /* Read original configuration */
+ conf = conf_orig = readl_relaxed(spicc->base + SPICC_CONREG);
+
+ /* Select closest divider */
+ conf = meson_spicc_setup_speed(spicc, conf, xfer->speed_hz);
+
+ /* Setup word width */
+ conf &= ~SPICC_BITLENGTH_MASK;
+ conf |= FIELD_PREP(SPICC_BITLENGTH_MASK,
+ (spicc->bytes_per_word << 3) - 1);
+
+ /* Ignore if unchanged */
+ if (conf != conf_orig)
+ writel_relaxed(conf, spicc->base + SPICC_CONREG);
+}
+
+static int meson_spicc_transfer_one(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct meson_spicc_device *spicc = spi_master_get_devdata(master);
+ unsigned int burst_len;
+ u32 irq = 0;
+
+ /* Store current transfer */
+ spicc->xfer = xfer;
+
+ /* Setup transfer parameters */
+ spicc->tx_buf = (u8 *)xfer->tx_buf;
+ spicc->rx_buf = (u8 *)xfer->rx_buf;
+ spicc->xfer_remain = xfer->len;
+
+ /* Pre-calculate word size */
+ spicc->bytes_per_word =
+ DIV_ROUND_UP(spicc->xfer->bits_per_word, 8);
+
+ /* Setup transfer parameters */
+ meson_spicc_setup_xfer(spicc, xfer);
+
+ burst_len = min_t(unsigned int,
+ spicc->xfer_remain / spicc->bytes_per_word,
+ SPICC_BURST_MAX);
+
+ meson_spicc_setup_burst(spicc, burst_len);
+
+ irq = meson_spicc_setup_rx_irq(spicc, irq);
+
+ /* Start burst */
+ writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
+
+ /* Enable interrupts */
+ writel_relaxed(irq, spicc->base + SPICC_INTREG);
+
+ return 1;
+}
+
+static int meson_spicc_prepare_message(struct spi_master *master,
+ struct spi_message *message)
+{
+ struct meson_spicc_device *spicc = spi_master_get_devdata(master);
+ struct spi_device *spi = message->spi;
+ u32 conf = 0;
+
+ /* Store current message */
+ spicc->message = message;
+
+ /* Enable Master */
+ conf |= SPICC_ENABLE;
+ conf |= SPICC_MODE_MASTER;
+
+ /* SMC = 0 */
+
+ /* Setup transfer mode */
+ if (spi->mode & SPI_CPOL)
+ conf |= SPICC_POL;
+ else
+ conf &= ~SPICC_POL;
+
+ if (spi->mode & SPI_CPHA)
+ conf |= SPICC_PHA;
+ else
+ conf &= ~SPICC_PHA;
+
+ /* SSCTL = 0 */
+
+ if (spi->mode & SPI_CS_HIGH)
+ conf |= SPICC_SSPOL;
+ else
+ conf &= ~SPICC_SSPOL;
+
+ if (spi->mode & SPI_READY)
+ conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_LOWLEVEL);
+ else
+ conf |= FIELD_PREP(SPICC_DRCTL_MASK, SPICC_DRCTL_IGNORE);
+
+ /* Select CS */
+ conf |= FIELD_PREP(SPICC_CS_MASK, spi->chip_select);
+
+ /* Default Clock rate core/4 */
+
+ /* Default 8bit word */
+ conf |= FIELD_PREP(SPICC_BITLENGTH_MASK, 8 - 1);
+
+ writel_relaxed(conf, spicc->base + SPICC_CONREG);
+
+ /* Setup no wait cycles by default */
+ writel_relaxed(0, spicc->base + SPICC_PERIODREG);
+
+ writel_bits_relaxed(BIT(24), BIT(24), spicc->base + SPICC_TESTREG);
+
+ return 0;
+}
+
+static int meson_spicc_unprepare_transfer(struct spi_master *master)
+{
+ struct meson_spicc_device *spicc = spi_master_get_devdata(master);
+
+ /* Disable all IRQs */
+ writel(0, spicc->base + SPICC_INTREG);
+
+ /* Disable controller */
+ writel_bits_relaxed(SPICC_ENABLE, 0, spicc->base + SPICC_CONREG);
+
+ device_reset_optional(&spicc->pdev->dev);
+
+ return 0;
+}
+
+static int meson_spicc_setup(struct spi_device *spi)
+{
+ int ret = 0;
+
+ if (!spi->controller_state)
+ spi->controller_state = spi_master_get_devdata(spi->master);
+ else if (gpio_is_valid(spi->cs_gpio))
+ goto out_gpio;
+ else if (spi->cs_gpio == -ENOENT)
+ return 0;
+
+ if (gpio_is_valid(spi->cs_gpio)) {
+ ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
+ if (ret) {
+ dev_err(&spi->dev, "failed to request cs gpio\n");
+ return ret;
+ }
+ }
+
+out_gpio:
+ ret = gpio_direction_output(spi->cs_gpio,
+ !(spi->mode & SPI_CS_HIGH));
+
+ return ret;
+}
+
+static void meson_spicc_cleanup(struct spi_device *spi)
+{
+ if (gpio_is_valid(spi->cs_gpio))
+ gpio_free(spi->cs_gpio);
+
+ spi->controller_state = NULL;
+}
+
+static int meson_spicc_probe(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct meson_spicc_device *spicc;
+ struct resource *res;
+ int ret, irq, rate;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*spicc));
+ if (!master) {
+ dev_err(&pdev->dev, "master allocation failed\n");
+ return -ENOMEM;
+ }
+ spicc = spi_master_get_devdata(master);
+ spicc->master = master;
+
+ spicc->pdev = pdev;
+ platform_set_drvdata(pdev, spicc);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ spicc->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(spicc->base)) {
+ dev_err(&pdev->dev, "io resource mapping failed\n");
+ ret = PTR_ERR(spicc->base);
+ goto out_master;
+ }
+
+ /* Disable all IRQs */
+ writel_relaxed(0, spicc->base + SPICC_INTREG);
+
+ irq = platform_get_irq(pdev, 0);
+ ret = devm_request_irq(&pdev->dev, irq, meson_spicc_irq,
+ 0, NULL, spicc);
+ if (ret) {
+ dev_err(&pdev->dev, "irq request failed\n");
+ goto out_master;
+ }
+
+ spicc->core = devm_clk_get(&pdev->dev, "core");
+ if (IS_ERR(spicc->core)) {
+ dev_err(&pdev->dev, "core clock request failed\n");
+ ret = PTR_ERR(spicc->core);
+ goto out_master;
+ }
+
+ ret = clk_prepare_enable(spicc->core);
+ if (ret) {
+ dev_err(&pdev->dev, "core clock enable failed\n");
+ goto out_master;
+ }
+ rate = clk_get_rate(spicc->core);
+
+ device_reset_optional(&pdev->dev);
+
+ master->num_chipselect = 4;
+ master->dev.of_node = pdev->dev.of_node;
+ master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH;
+ master->bits_per_word_mask = SPI_BPW_MASK(32) |
+ SPI_BPW_MASK(24) |
+ SPI_BPW_MASK(16) |
+ SPI_BPW_MASK(8);
+ master->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX);
+ master->min_speed_hz = rate >> 9;
+ master->setup = meson_spicc_setup;
+ master->cleanup = meson_spicc_cleanup;
+ master->prepare_message = meson_spicc_prepare_message;
+ master->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
+ master->transfer_one = meson_spicc_transfer_one;
+
+ /* Setup max rate according to the Meson GX datasheet */
+ if ((rate >> 2) > SPICC_MAX_FREQ)
+ master->max_speed_hz = SPICC_MAX_FREQ;
+ else
+ master->max_speed_hz = rate >> 2;
+
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (!ret)
+ return 0;
+
+ dev_err(&pdev->dev, "spi master registration failed\n");
+
+out_master:
+ spi_master_put(master);
+
+ return ret;
+}
+
+static int meson_spicc_remove(struct platform_device *pdev)
+{
+ struct meson_spicc_device *spicc = platform_get_drvdata(pdev);
+
+ /* Disable SPI */
+ writel(0, spicc->base + SPICC_CONREG);
+
+ clk_disable_unprepare(spicc->core);
+
+ return 0;
+}
+
+static const struct of_device_id meson_spicc_of_match[] = {
+ { .compatible = "amlogic,meson-gx-spicc", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, meson_spicc_of_match);
+
+static struct platform_driver meson_spicc_driver = {
+ .probe = meson_spicc_probe,
+ .remove = meson_spicc_remove,
+ .driver = {
+ .name = "meson-spicc",
+ .of_match_table = of_match_ptr(meson_spicc_of_match),
+ },
+};
+
+module_platform_driver(meson_spicc_driver);
+
+MODULE_DESCRIPTION("Meson SPI Communication Controller driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong at baylibre.com>");
+MODULE_LICENSE("GPL");
--
2.11.0
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