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487 lines
12 KiB
487 lines
12 KiB
From cbd66c626e16743b05af807ad48012c0a097b9fb Mon Sep 17 00:00:00 2001
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From: Stefan Roese <sr@denx.de>
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Date: Mon, 25 Mar 2019 09:29:25 +0100
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Subject: [PATCH] spi: mt7621: Move SPI driver out of staging
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This patch moves the MT7621 SPI driver, which is used on some Ralink /
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MediaTek MT76xx MIPS SoC's, out of the staging directory. No changes to
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the source code are done in this patch.
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This driver version was tested successfully on an MT7688 based platform
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with an SPI NOR on CS0 and an SPI NAND on CS1 without any issues (so
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far).
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This patch also documents the devicetree bindings for the MT7621 SPI
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device driver.
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Signed-off-by: Stefan Roese <sr@denx.de>
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Cc: Rob Herring <robh@kernel.org>
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Cc: Mark Brown <broonie@kernel.org>
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Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Cc: NeilBrown <neil@brown.name>
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Cc: Sankalp Negi <sankalpnegi2310@gmail.com>
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Cc: Chuanhong Guo <gch981213@gmail.com>
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Cc: John Crispin <john@phrozen.org>
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Cc: Armando Miraglia <arma2ff0@gmail.com>
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Signed-off-by: Mark Brown <broonie@kernel.org>
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---
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.../devicetree/bindings/spi/spi-mt7621.txt | 26 ++++++
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drivers/spi/Kconfig | 6 ++
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drivers/spi/Makefile | 1 +
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.../{staging/mt7621-spi => spi}/spi-mt7621.c | 83 +++++++++----------
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drivers/staging/Kconfig | 2 -
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drivers/staging/Makefile | 1 -
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drivers/staging/mt7621-spi/Kconfig | 6 --
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drivers/staging/mt7621-spi/Makefile | 1 -
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drivers/staging/mt7621-spi/TODO | 5 --
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9 files changed, 74 insertions(+), 57 deletions(-)
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create mode 100644 Documentation/devicetree/bindings/spi/spi-mt7621.txt
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rename drivers/{staging/mt7621-spi => spi}/spi-mt7621.c (88%)
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delete mode 100644 drivers/staging/mt7621-spi/Kconfig
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delete mode 100644 drivers/staging/mt7621-spi/Makefile
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delete mode 100644 drivers/staging/mt7621-spi/TODO
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--- a/drivers/spi/Kconfig
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+++ b/drivers/spi/Kconfig
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@@ -569,6 +569,12 @@ config SPI_RT2880
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help
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This selects a driver for the Ralink RT288x/RT305x SPI Controller.
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+config SPI_MT7621
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+ tristate "MediaTek MT7621 SPI Controller"
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+ depends on RALINK
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+ help
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+ This selects a driver for the MediaTek MT7621 SPI Controller.
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+
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config SPI_S3C24XX
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tristate "Samsung S3C24XX series SPI"
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depends on ARCH_S3C24XX
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--- a/drivers/spi/Makefile
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+++ b/drivers/spi/Makefile
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@@ -60,6 +60,7 @@ obj-$(CONFIG_SPI_MPC512x_PSC) += spi-mp
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obj-$(CONFIG_SPI_MPC52xx_PSC) += spi-mpc52xx-psc.o
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obj-$(CONFIG_SPI_MPC52xx) += spi-mpc52xx.o
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obj-$(CONFIG_SPI_MT65XX) += spi-mt65xx.o
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+obj-$(CONFIG_SPI_MT7621) += spi-mt7621.o
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obj-$(CONFIG_SPI_MXS) += spi-mxs.o
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obj-$(CONFIG_SPI_NUC900) += spi-nuc900.o
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obj-$(CONFIG_SPI_OC_TINY) += spi-oc-tiny.o
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--- /dev/null
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+++ b/drivers/spi/spi-mt7621.c
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@@ -0,0 +1,416 @@
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+// SPDX-License-Identifier: GPL-2.0
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+//
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+// spi-mt7621.c -- MediaTek MT7621 SPI controller driver
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+//
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+// Copyright (C) 2011 Sergiy <piratfm@gmail.com>
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+// Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
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+// Copyright (C) 2014-2015 Felix Fietkau <nbd@nbd.name>
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+//
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+// Some parts are based on spi-orion.c:
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+// Author: Shadi Ammouri <shadi@marvell.com>
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+// Copyright (C) 2007-2008 Marvell Ltd.
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+
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+#include <linux/clk.h>
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+#include <linux/delay.h>
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+#include <linux/io.h>
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+#include <linux/module.h>
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+#include <linux/of_device.h>
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+#include <linux/reset.h>
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+#include <linux/spi/spi.h>
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+
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+#define DRIVER_NAME "spi-mt7621"
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+
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+/* in usec */
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+#define RALINK_SPI_WAIT_MAX_LOOP 2000
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+
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+/* SPISTAT register bit field */
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+#define SPISTAT_BUSY BIT(0)
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+
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+#define MT7621_SPI_TRANS 0x00
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+#define SPITRANS_BUSY BIT(16)
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+
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+#define MT7621_SPI_OPCODE 0x04
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+#define MT7621_SPI_DATA0 0x08
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+#define MT7621_SPI_DATA4 0x18
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+#define SPI_CTL_TX_RX_CNT_MASK 0xff
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+#define SPI_CTL_START BIT(8)
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+
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+#define MT7621_SPI_MASTER 0x28
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+#define MASTER_MORE_BUFMODE BIT(2)
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+#define MASTER_FULL_DUPLEX BIT(10)
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+#define MASTER_RS_CLK_SEL GENMASK(27, 16)
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+#define MASTER_RS_CLK_SEL_SHIFT 16
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+#define MASTER_RS_SLAVE_SEL GENMASK(31, 29)
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+
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+#define MT7621_SPI_MOREBUF 0x2c
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+#define MT7621_SPI_POLAR 0x38
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+#define MT7621_SPI_SPACE 0x3c
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+
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+#define MT7621_CPHA BIT(5)
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+#define MT7621_CPOL BIT(4)
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+#define MT7621_LSB_FIRST BIT(3)
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+
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+struct mt7621_spi {
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+ struct spi_controller *master;
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+ void __iomem *base;
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+ unsigned int sys_freq;
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+ unsigned int speed;
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+ struct clk *clk;
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+ int pending_write;
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+};
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+
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+static inline struct mt7621_spi *spidev_to_mt7621_spi(struct spi_device *spi)
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+{
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+ return spi_controller_get_devdata(spi->master);
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+}
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+
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+static inline u32 mt7621_spi_read(struct mt7621_spi *rs, u32 reg)
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+{
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+ return ioread32(rs->base + reg);
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+}
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+
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+static inline void mt7621_spi_write(struct mt7621_spi *rs, u32 reg, u32 val)
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+{
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+ iowrite32(val, rs->base + reg);
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+}
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+
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+static void mt7621_spi_set_cs(struct spi_device *spi, int enable)
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+{
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+ struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
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+ int cs = spi->chip_select;
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+ u32 polar = 0;
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+ u32 master;
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+
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+ /*
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+ * Select SPI device 7, enable "more buffer mode" and disable
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+ * full-duplex (only half-duplex really works on this chip
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+ * reliably)
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+ */
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+ master = mt7621_spi_read(rs, MT7621_SPI_MASTER);
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+ master |= MASTER_RS_SLAVE_SEL | MASTER_MORE_BUFMODE;
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+ master &= ~MASTER_FULL_DUPLEX;
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+ mt7621_spi_write(rs, MT7621_SPI_MASTER, master);
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+
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+ rs->pending_write = 0;
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+
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+ if (enable)
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+ polar = BIT(cs);
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+ mt7621_spi_write(rs, MT7621_SPI_POLAR, polar);
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+}
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+
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+static int mt7621_spi_prepare(struct spi_device *spi, unsigned int speed)
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+{
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+ struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
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+ u32 rate;
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+ u32 reg;
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+
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+ dev_dbg(&spi->dev, "speed:%u\n", speed);
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+
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+ rate = DIV_ROUND_UP(rs->sys_freq, speed);
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+ dev_dbg(&spi->dev, "rate-1:%u\n", rate);
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+
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+ if (rate > 4097)
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+ return -EINVAL;
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+
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+ if (rate < 2)
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+ rate = 2;
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+
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+ reg = mt7621_spi_read(rs, MT7621_SPI_MASTER);
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+ reg &= ~MASTER_RS_CLK_SEL;
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+ reg |= (rate - 2) << MASTER_RS_CLK_SEL_SHIFT;
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+ rs->speed = speed;
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+
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+ reg &= ~MT7621_LSB_FIRST;
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+ if (spi->mode & SPI_LSB_FIRST)
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+ reg |= MT7621_LSB_FIRST;
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+
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+ /*
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+ * This SPI controller seems to be tested on SPI flash only and some
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+ * bits are swizzled under other SPI modes probably due to incorrect
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+ * wiring inside the silicon. Only mode 0 works correctly.
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+ */
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+ reg &= ~(MT7621_CPHA | MT7621_CPOL);
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+
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+ mt7621_spi_write(rs, MT7621_SPI_MASTER, reg);
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+
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+ return 0;
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+}
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+
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+static inline int mt7621_spi_wait_till_ready(struct mt7621_spi *rs)
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+{
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+ int i;
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+
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+ for (i = 0; i < RALINK_SPI_WAIT_MAX_LOOP; i++) {
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+ u32 status;
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+
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+ status = mt7621_spi_read(rs, MT7621_SPI_TRANS);
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+ if ((status & SPITRANS_BUSY) == 0)
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+ return 0;
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+ cpu_relax();
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+ udelay(1);
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+ }
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+
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+ return -ETIMEDOUT;
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+}
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+
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+static void mt7621_spi_read_half_duplex(struct mt7621_spi *rs,
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+ int rx_len, u8 *buf)
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+{
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+ int tx_len;
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+
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+ /*
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+ * Combine with any pending write, and perform one or more half-duplex
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+ * transactions reading 'len' bytes. Data to be written is already in
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+ * MT7621_SPI_DATA.
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+ */
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+ tx_len = rs->pending_write;
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+ rs->pending_write = 0;
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+
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+ while (rx_len || tx_len) {
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+ int i;
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+ u32 val = (min(tx_len, 4) * 8) << 24;
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+ int rx = min(rx_len, 32);
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+
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+ if (tx_len > 4)
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+ val |= (tx_len - 4) * 8;
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+ val |= (rx * 8) << 12;
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+ mt7621_spi_write(rs, MT7621_SPI_MOREBUF, val);
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+
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+ tx_len = 0;
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+
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+ val = mt7621_spi_read(rs, MT7621_SPI_TRANS);
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+ val |= SPI_CTL_START;
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+ mt7621_spi_write(rs, MT7621_SPI_TRANS, val);
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+
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+ mt7621_spi_wait_till_ready(rs);
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+
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+ for (i = 0; i < rx; i++) {
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+ if ((i % 4) == 0)
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+ val = mt7621_spi_read(rs, MT7621_SPI_DATA0 + i);
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+ *buf++ = val & 0xff;
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+ val >>= 8;
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+ }
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+
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+ rx_len -= i;
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+ }
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+}
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+
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+static inline void mt7621_spi_flush(struct mt7621_spi *rs)
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+{
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+ mt7621_spi_read_half_duplex(rs, 0, NULL);
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+}
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+
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+static void mt7621_spi_write_half_duplex(struct mt7621_spi *rs,
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+ int tx_len, const u8 *buf)
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+{
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+ int len = rs->pending_write;
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+ int val = 0;
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+
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+ if (len & 3) {
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+ val = mt7621_spi_read(rs, MT7621_SPI_OPCODE + (len & ~3));
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+ if (len < 4) {
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+ val <<= (4 - len) * 8;
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+ val = swab32(val);
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+ }
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+ }
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+
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+ while (tx_len > 0) {
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+ if (len >= 36) {
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+ rs->pending_write = len;
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+ mt7621_spi_flush(rs);
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+ len = 0;
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+ }
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+
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+ val |= *buf++ << (8 * (len & 3));
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+ len++;
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+ if ((len & 3) == 0) {
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+ if (len == 4)
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+ /* The byte-order of the opcode is weird! */
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+ val = swab32(val);
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+ mt7621_spi_write(rs, MT7621_SPI_OPCODE + len - 4, val);
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+ val = 0;
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+ }
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+ tx_len -= 1;
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+ }
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+
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+ if (len & 3) {
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+ if (len < 4) {
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+ val = swab32(val);
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+ val >>= (4 - len) * 8;
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+ }
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+ mt7621_spi_write(rs, MT7621_SPI_OPCODE + (len & ~3), val);
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+ }
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+
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+ rs->pending_write = len;
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+}
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+
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+static int mt7621_spi_transfer_one_message(struct spi_controller *master,
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+ struct spi_message *m)
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+{
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+ struct mt7621_spi *rs = spi_controller_get_devdata(master);
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+ struct spi_device *spi = m->spi;
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+ unsigned int speed = spi->max_speed_hz;
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+ struct spi_transfer *t = NULL;
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+ int status = 0;
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+
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+ mt7621_spi_wait_till_ready(rs);
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+
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+ list_for_each_entry(t, &m->transfers, transfer_list)
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+ if (t->speed_hz < speed)
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+ speed = t->speed_hz;
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+
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+ if (mt7621_spi_prepare(spi, speed)) {
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+ status = -EIO;
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+ goto msg_done;
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+ }
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+
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+ /* Assert CS */
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+ mt7621_spi_set_cs(spi, 1);
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+
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+ m->actual_length = 0;
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+ list_for_each_entry(t, &m->transfers, transfer_list) {
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+ if ((t->rx_buf) && (t->tx_buf)) {
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+ /*
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+ * This controller will shift some extra data out
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+ * of spi_opcode if (mosi_bit_cnt > 0) &&
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+ * (cmd_bit_cnt == 0). So the claimed full-duplex
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+ * support is broken since we have no way to read
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+ * the MISO value during that bit.
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+ */
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+ status = -EIO;
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+ goto msg_done;
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+ } else if (t->rx_buf) {
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+ mt7621_spi_read_half_duplex(rs, t->len, t->rx_buf);
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+ } else if (t->tx_buf) {
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+ mt7621_spi_write_half_duplex(rs, t->len, t->tx_buf);
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+ }
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+ m->actual_length += t->len;
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+ }
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+
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+ /* Flush data and deassert CS */
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+ mt7621_spi_flush(rs);
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+ mt7621_spi_set_cs(spi, 0);
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+
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+msg_done:
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+ m->status = status;
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+ spi_finalize_current_message(master);
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+
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+ return 0;
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+}
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+
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+static int mt7621_spi_setup(struct spi_device *spi)
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+{
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+ struct mt7621_spi *rs = spidev_to_mt7621_spi(spi);
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+
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+ if ((spi->max_speed_hz == 0) ||
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+ (spi->max_speed_hz > (rs->sys_freq / 2)))
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+ spi->max_speed_hz = (rs->sys_freq / 2);
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+
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+ if (spi->max_speed_hz < (rs->sys_freq / 4097)) {
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+ dev_err(&spi->dev, "setup: requested speed is too low %d Hz\n",
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+ spi->max_speed_hz);
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+ return -EINVAL;
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+ }
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+
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+ return 0;
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+}
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+
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+static const struct of_device_id mt7621_spi_match[] = {
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+ { .compatible = "ralink,mt7621-spi" },
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+ {},
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+};
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+MODULE_DEVICE_TABLE(of, mt7621_spi_match);
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+
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+static int mt7621_spi_probe(struct platform_device *pdev)
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+{
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+ const struct of_device_id *match;
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+ struct spi_controller *master;
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+ struct mt7621_spi *rs;
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+ void __iomem *base;
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+ struct resource *r;
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+ int status = 0;
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+ struct clk *clk;
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+ int ret;
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+
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+ match = of_match_device(mt7621_spi_match, &pdev->dev);
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+ if (!match)
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+ return -EINVAL;
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+
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+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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+ base = devm_ioremap_resource(&pdev->dev, r);
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+ if (IS_ERR(base))
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+ return PTR_ERR(base);
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+
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+ clk = devm_clk_get(&pdev->dev, NULL);
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+ if (IS_ERR(clk)) {
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+ dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
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+ status);
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+ return PTR_ERR(clk);
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+ }
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+
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+ status = clk_prepare_enable(clk);
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+ if (status)
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+ return status;
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+
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+ master = spi_alloc_master(&pdev->dev, sizeof(*rs));
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+ if (!master) {
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+ dev_info(&pdev->dev, "master allocation failed\n");
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+ return -ENOMEM;
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+ }
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+
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+ master->mode_bits = SPI_LSB_FIRST;
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+ master->flags = SPI_CONTROLLER_HALF_DUPLEX;
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+ master->setup = mt7621_spi_setup;
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+ master->transfer_one_message = mt7621_spi_transfer_one_message;
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+ master->bits_per_word_mask = SPI_BPW_MASK(8);
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+ master->dev.of_node = pdev->dev.of_node;
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+ master->num_chipselect = 2;
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+
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+ dev_set_drvdata(&pdev->dev, master);
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+
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+ rs = spi_controller_get_devdata(master);
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+ rs->base = base;
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+ rs->clk = clk;
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+ rs->master = master;
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+ rs->sys_freq = clk_get_rate(rs->clk);
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+ rs->pending_write = 0;
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+ dev_info(&pdev->dev, "sys_freq: %u\n", rs->sys_freq);
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+
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+ ret = device_reset(&pdev->dev);
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+ if (ret) {
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+ dev_err(&pdev->dev, "SPI reset failed!\n");
|
|
+ return ret;
|
|
+ }
|
|
+
|
|
+ return devm_spi_register_controller(&pdev->dev, master);
|
|
+}
|
|
+
|
|
+static int mt7621_spi_remove(struct platform_device *pdev)
|
|
+{
|
|
+ struct spi_controller *master;
|
|
+ struct mt7621_spi *rs;
|
|
+
|
|
+ master = dev_get_drvdata(&pdev->dev);
|
|
+ rs = spi_controller_get_devdata(master);
|
|
+
|
|
+ clk_disable_unprepare(rs->clk);
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+MODULE_ALIAS("platform:" DRIVER_NAME);
|
|
+
|
|
+static struct platform_driver mt7621_spi_driver = {
|
|
+ .driver = {
|
|
+ .name = DRIVER_NAME,
|
|
+ .of_match_table = mt7621_spi_match,
|
|
+ },
|
|
+ .probe = mt7621_spi_probe,
|
|
+ .remove = mt7621_spi_remove,
|
|
+};
|
|
+
|
|
+module_platform_driver(mt7621_spi_driver);
|
|
+
|
|
+MODULE_DESCRIPTION("MT7621 SPI driver");
|
|
+MODULE_AUTHOR("Felix Fietkau <nbd@nbd.name>");
|
|
+MODULE_LICENSE("GPL");
|
|
|