forked from Minki/linux
ff18e1ef04
The HSSPI block actually has two clock inputs, one for gating the block, and one for the PLL rate. To allow these to be represented as two clocks, add support for retrieving the rate from a separate "pll" clock, if the "hsspi" clock does not provide one. Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
487 lines
13 KiB
C
487 lines
13 KiB
C
/*
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* Broadcom BCM63XX High Speed SPI Controller driver
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*
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* Copyright 2000-2010 Broadcom Corporation
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* Copyright 2012-2013 Jonas Gorski <jogo@openwrt.org>
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*
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* Licensed under the GNU/GPL. See COPYING for details.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/clk.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/delay.h>
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#include <linux/dma-mapping.h>
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#include <linux/err.h>
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#include <linux/interrupt.h>
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#include <linux/spi/spi.h>
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#include <linux/mutex.h>
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#define HSSPI_GLOBAL_CTRL_REG 0x0
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#define GLOBAL_CTRL_CS_POLARITY_SHIFT 0
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#define GLOBAL_CTRL_CS_POLARITY_MASK 0x000000ff
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#define GLOBAL_CTRL_PLL_CLK_CTRL_SHIFT 8
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#define GLOBAL_CTRL_PLL_CLK_CTRL_MASK 0x0000ff00
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#define GLOBAL_CTRL_CLK_GATE_SSOFF BIT(16)
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#define GLOBAL_CTRL_CLK_POLARITY BIT(17)
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#define GLOBAL_CTRL_MOSI_IDLE BIT(18)
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#define HSSPI_GLOBAL_EXT_TRIGGER_REG 0x4
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#define HSSPI_INT_STATUS_REG 0x8
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#define HSSPI_INT_STATUS_MASKED_REG 0xc
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#define HSSPI_INT_MASK_REG 0x10
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#define HSSPI_PINGx_CMD_DONE(i) BIT((i * 8) + 0)
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#define HSSPI_PINGx_RX_OVER(i) BIT((i * 8) + 1)
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#define HSSPI_PINGx_TX_UNDER(i) BIT((i * 8) + 2)
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#define HSSPI_PINGx_POLL_TIMEOUT(i) BIT((i * 8) + 3)
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#define HSSPI_PINGx_CTRL_INVAL(i) BIT((i * 8) + 4)
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#define HSSPI_INT_CLEAR_ALL 0xff001f1f
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#define HSSPI_PINGPONG_COMMAND_REG(x) (0x80 + (x) * 0x40)
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#define PINGPONG_CMD_COMMAND_MASK 0xf
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#define PINGPONG_COMMAND_NOOP 0
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#define PINGPONG_COMMAND_START_NOW 1
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#define PINGPONG_COMMAND_START_TRIGGER 2
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#define PINGPONG_COMMAND_HALT 3
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#define PINGPONG_COMMAND_FLUSH 4
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#define PINGPONG_CMD_PROFILE_SHIFT 8
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#define PINGPONG_CMD_SS_SHIFT 12
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#define HSSPI_PINGPONG_STATUS_REG(x) (0x84 + (x) * 0x40)
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#define HSSPI_PROFILE_CLK_CTRL_REG(x) (0x100 + (x) * 0x20)
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#define CLK_CTRL_FREQ_CTRL_MASK 0x0000ffff
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#define CLK_CTRL_SPI_CLK_2X_SEL BIT(14)
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#define CLK_CTRL_ACCUM_RST_ON_LOOP BIT(15)
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#define HSSPI_PROFILE_SIGNAL_CTRL_REG(x) (0x104 + (x) * 0x20)
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#define SIGNAL_CTRL_LATCH_RISING BIT(12)
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#define SIGNAL_CTRL_LAUNCH_RISING BIT(13)
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#define SIGNAL_CTRL_ASYNC_INPUT_PATH BIT(16)
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#define HSSPI_PROFILE_MODE_CTRL_REG(x) (0x108 + (x) * 0x20)
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#define MODE_CTRL_MULTIDATA_RD_STRT_SHIFT 8
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#define MODE_CTRL_MULTIDATA_WR_STRT_SHIFT 12
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#define MODE_CTRL_MULTIDATA_RD_SIZE_SHIFT 16
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#define MODE_CTRL_MULTIDATA_WR_SIZE_SHIFT 18
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#define MODE_CTRL_MODE_3WIRE BIT(20)
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#define MODE_CTRL_PREPENDBYTE_CNT_SHIFT 24
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#define HSSPI_FIFO_REG(x) (0x200 + (x) * 0x200)
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#define HSSPI_OP_MULTIBIT BIT(11)
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#define HSSPI_OP_CODE_SHIFT 13
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#define HSSPI_OP_SLEEP (0 << HSSPI_OP_CODE_SHIFT)
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#define HSSPI_OP_READ_WRITE (1 << HSSPI_OP_CODE_SHIFT)
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#define HSSPI_OP_WRITE (2 << HSSPI_OP_CODE_SHIFT)
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#define HSSPI_OP_READ (3 << HSSPI_OP_CODE_SHIFT)
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#define HSSPI_OP_SETIRQ (4 << HSSPI_OP_CODE_SHIFT)
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#define HSSPI_BUFFER_LEN 512
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#define HSSPI_OPCODE_LEN 2
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#define HSSPI_MAX_PREPEND_LEN 15
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#define HSSPI_MAX_SYNC_CLOCK 30000000
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#define HSSPI_BUS_NUM 1 /* 0 is legacy SPI */
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struct bcm63xx_hsspi {
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struct completion done;
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struct mutex bus_mutex;
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struct platform_device *pdev;
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struct clk *clk;
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void __iomem *regs;
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u8 __iomem *fifo;
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u32 speed_hz;
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u8 cs_polarity;
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};
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static void bcm63xx_hsspi_set_cs(struct bcm63xx_hsspi *bs, unsigned cs,
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bool active)
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{
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u32 reg;
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mutex_lock(&bs->bus_mutex);
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reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG);
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reg &= ~BIT(cs);
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if (active == !(bs->cs_polarity & BIT(cs)))
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reg |= BIT(cs);
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__raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG);
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mutex_unlock(&bs->bus_mutex);
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}
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static void bcm63xx_hsspi_set_clk(struct bcm63xx_hsspi *bs,
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struct spi_device *spi, int hz)
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{
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unsigned profile = spi->chip_select;
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u32 reg;
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reg = DIV_ROUND_UP(2048, DIV_ROUND_UP(bs->speed_hz, hz));
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__raw_writel(CLK_CTRL_ACCUM_RST_ON_LOOP | reg,
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bs->regs + HSSPI_PROFILE_CLK_CTRL_REG(profile));
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reg = __raw_readl(bs->regs + HSSPI_PROFILE_SIGNAL_CTRL_REG(profile));
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if (hz > HSSPI_MAX_SYNC_CLOCK)
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reg |= SIGNAL_CTRL_ASYNC_INPUT_PATH;
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else
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reg &= ~SIGNAL_CTRL_ASYNC_INPUT_PATH;
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__raw_writel(reg, bs->regs + HSSPI_PROFILE_SIGNAL_CTRL_REG(profile));
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mutex_lock(&bs->bus_mutex);
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/* setup clock polarity */
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reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG);
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reg &= ~GLOBAL_CTRL_CLK_POLARITY;
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if (spi->mode & SPI_CPOL)
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reg |= GLOBAL_CTRL_CLK_POLARITY;
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__raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG);
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mutex_unlock(&bs->bus_mutex);
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}
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static int bcm63xx_hsspi_do_txrx(struct spi_device *spi, struct spi_transfer *t)
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{
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struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master);
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unsigned chip_select = spi->chip_select;
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u16 opcode = 0;
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int pending = t->len;
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int step_size = HSSPI_BUFFER_LEN;
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const u8 *tx = t->tx_buf;
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u8 *rx = t->rx_buf;
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bcm63xx_hsspi_set_clk(bs, spi, t->speed_hz);
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bcm63xx_hsspi_set_cs(bs, spi->chip_select, true);
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if (tx && rx)
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opcode = HSSPI_OP_READ_WRITE;
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else if (tx)
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opcode = HSSPI_OP_WRITE;
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else if (rx)
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opcode = HSSPI_OP_READ;
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if (opcode != HSSPI_OP_READ)
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step_size -= HSSPI_OPCODE_LEN;
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if ((opcode == HSSPI_OP_READ && t->rx_nbits == SPI_NBITS_DUAL) ||
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(opcode == HSSPI_OP_WRITE && t->tx_nbits == SPI_NBITS_DUAL))
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opcode |= HSSPI_OP_MULTIBIT;
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__raw_writel(1 << MODE_CTRL_MULTIDATA_WR_SIZE_SHIFT |
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1 << MODE_CTRL_MULTIDATA_RD_SIZE_SHIFT | 0xff,
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bs->regs + HSSPI_PROFILE_MODE_CTRL_REG(chip_select));
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while (pending > 0) {
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int curr_step = min_t(int, step_size, pending);
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reinit_completion(&bs->done);
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if (tx) {
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memcpy_toio(bs->fifo + HSSPI_OPCODE_LEN, tx, curr_step);
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tx += curr_step;
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}
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__raw_writew(opcode | curr_step, bs->fifo);
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/* enable interrupt */
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__raw_writel(HSSPI_PINGx_CMD_DONE(0),
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bs->regs + HSSPI_INT_MASK_REG);
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/* start the transfer */
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__raw_writel(!chip_select << PINGPONG_CMD_SS_SHIFT |
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chip_select << PINGPONG_CMD_PROFILE_SHIFT |
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PINGPONG_COMMAND_START_NOW,
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bs->regs + HSSPI_PINGPONG_COMMAND_REG(0));
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if (wait_for_completion_timeout(&bs->done, HZ) == 0) {
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dev_err(&bs->pdev->dev, "transfer timed out!\n");
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return -ETIMEDOUT;
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}
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if (rx) {
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memcpy_fromio(rx, bs->fifo, curr_step);
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rx += curr_step;
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}
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pending -= curr_step;
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}
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return 0;
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}
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static int bcm63xx_hsspi_setup(struct spi_device *spi)
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{
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struct bcm63xx_hsspi *bs = spi_master_get_devdata(spi->master);
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u32 reg;
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reg = __raw_readl(bs->regs +
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HSSPI_PROFILE_SIGNAL_CTRL_REG(spi->chip_select));
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reg &= ~(SIGNAL_CTRL_LAUNCH_RISING | SIGNAL_CTRL_LATCH_RISING);
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if (spi->mode & SPI_CPHA)
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reg |= SIGNAL_CTRL_LAUNCH_RISING;
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else
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reg |= SIGNAL_CTRL_LATCH_RISING;
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__raw_writel(reg, bs->regs +
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HSSPI_PROFILE_SIGNAL_CTRL_REG(spi->chip_select));
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mutex_lock(&bs->bus_mutex);
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reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG);
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/* only change actual polarities if there is no transfer */
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if ((reg & GLOBAL_CTRL_CS_POLARITY_MASK) == bs->cs_polarity) {
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if (spi->mode & SPI_CS_HIGH)
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reg |= BIT(spi->chip_select);
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else
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reg &= ~BIT(spi->chip_select);
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__raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG);
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}
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if (spi->mode & SPI_CS_HIGH)
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bs->cs_polarity |= BIT(spi->chip_select);
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else
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bs->cs_polarity &= ~BIT(spi->chip_select);
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mutex_unlock(&bs->bus_mutex);
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return 0;
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}
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static int bcm63xx_hsspi_transfer_one(struct spi_master *master,
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struct spi_message *msg)
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{
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struct bcm63xx_hsspi *bs = spi_master_get_devdata(master);
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struct spi_transfer *t;
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struct spi_device *spi = msg->spi;
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int status = -EINVAL;
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int dummy_cs;
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u32 reg;
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/* This controller does not support keeping CS active during idle.
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* To work around this, we use the following ugly hack:
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*
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* a. Invert the target chip select's polarity so it will be active.
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* b. Select a "dummy" chip select to use as the hardware target.
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* c. Invert the dummy chip select's polarity so it will be inactive
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* during the actual transfers.
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* d. Tell the hardware to send to the dummy chip select. Thanks to
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* the multiplexed nature of SPI the actual target will receive
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* the transfer and we see its response.
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*
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* e. At the end restore the polarities again to their default values.
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*/
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dummy_cs = !spi->chip_select;
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bcm63xx_hsspi_set_cs(bs, dummy_cs, true);
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list_for_each_entry(t, &msg->transfers, transfer_list) {
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status = bcm63xx_hsspi_do_txrx(spi, t);
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if (status)
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break;
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msg->actual_length += t->len;
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if (t->delay_usecs)
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udelay(t->delay_usecs);
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if (t->cs_change)
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bcm63xx_hsspi_set_cs(bs, spi->chip_select, false);
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}
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mutex_lock(&bs->bus_mutex);
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reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG);
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reg &= ~GLOBAL_CTRL_CS_POLARITY_MASK;
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reg |= bs->cs_polarity;
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__raw_writel(reg, bs->regs + HSSPI_GLOBAL_CTRL_REG);
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mutex_unlock(&bs->bus_mutex);
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msg->status = status;
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spi_finalize_current_message(master);
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return 0;
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}
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static irqreturn_t bcm63xx_hsspi_interrupt(int irq, void *dev_id)
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{
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struct bcm63xx_hsspi *bs = (struct bcm63xx_hsspi *)dev_id;
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if (__raw_readl(bs->regs + HSSPI_INT_STATUS_MASKED_REG) == 0)
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return IRQ_NONE;
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__raw_writel(HSSPI_INT_CLEAR_ALL, bs->regs + HSSPI_INT_STATUS_REG);
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__raw_writel(0, bs->regs + HSSPI_INT_MASK_REG);
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complete(&bs->done);
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return IRQ_HANDLED;
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}
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static int bcm63xx_hsspi_probe(struct platform_device *pdev)
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{
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struct spi_master *master;
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struct bcm63xx_hsspi *bs;
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struct resource *res_mem;
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void __iomem *regs;
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struct device *dev = &pdev->dev;
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struct clk *clk;
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int irq, ret;
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u32 reg, rate;
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irq = platform_get_irq(pdev, 0);
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if (irq < 0) {
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dev_err(dev, "no irq\n");
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return -ENXIO;
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}
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res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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regs = devm_ioremap_resource(dev, res_mem);
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if (IS_ERR(regs))
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return PTR_ERR(regs);
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clk = devm_clk_get(dev, "hsspi");
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if (IS_ERR(clk))
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return PTR_ERR(clk);
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rate = clk_get_rate(clk);
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if (!rate) {
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struct clk *pll_clk = devm_clk_get(dev, "pll");
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if (IS_ERR(pll_clk))
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return PTR_ERR(pll_clk);
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rate = clk_get_rate(pll_clk);
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if (!rate)
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return -EINVAL;
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}
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ret = clk_prepare_enable(clk);
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if (ret)
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return ret;
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master = spi_alloc_master(&pdev->dev, sizeof(*bs));
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if (!master) {
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ret = -ENOMEM;
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goto out_disable_clk;
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}
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bs = spi_master_get_devdata(master);
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bs->pdev = pdev;
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bs->clk = clk;
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bs->regs = regs;
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bs->speed_hz = rate;
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bs->fifo = (u8 __iomem *)(bs->regs + HSSPI_FIFO_REG(0));
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mutex_init(&bs->bus_mutex);
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init_completion(&bs->done);
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master->bus_num = HSSPI_BUS_NUM;
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master->num_chipselect = 8;
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master->setup = bcm63xx_hsspi_setup;
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master->transfer_one_message = bcm63xx_hsspi_transfer_one;
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master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH |
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SPI_RX_DUAL | SPI_TX_DUAL;
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master->bits_per_word_mask = SPI_BPW_MASK(8);
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master->auto_runtime_pm = true;
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platform_set_drvdata(pdev, master);
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/* Initialize the hardware */
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__raw_writel(0, bs->regs + HSSPI_INT_MASK_REG);
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/* clean up any pending interrupts */
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__raw_writel(HSSPI_INT_CLEAR_ALL, bs->regs + HSSPI_INT_STATUS_REG);
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/* read out default CS polarities */
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reg = __raw_readl(bs->regs + HSSPI_GLOBAL_CTRL_REG);
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bs->cs_polarity = reg & GLOBAL_CTRL_CS_POLARITY_MASK;
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__raw_writel(reg | GLOBAL_CTRL_CLK_GATE_SSOFF,
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bs->regs + HSSPI_GLOBAL_CTRL_REG);
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ret = devm_request_irq(dev, irq, bcm63xx_hsspi_interrupt, IRQF_SHARED,
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pdev->name, bs);
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if (ret)
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goto out_put_master;
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/* register and we are done */
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ret = devm_spi_register_master(dev, master);
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if (ret)
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goto out_put_master;
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return 0;
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out_put_master:
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spi_master_put(master);
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out_disable_clk:
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clk_disable_unprepare(clk);
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return ret;
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}
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static int bcm63xx_hsspi_remove(struct platform_device *pdev)
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{
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struct spi_master *master = platform_get_drvdata(pdev);
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struct bcm63xx_hsspi *bs = spi_master_get_devdata(master);
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/* reset the hardware and block queue progress */
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__raw_writel(0, bs->regs + HSSPI_INT_MASK_REG);
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clk_disable_unprepare(bs->clk);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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static int bcm63xx_hsspi_suspend(struct device *dev)
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{
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struct spi_master *master = dev_get_drvdata(dev);
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struct bcm63xx_hsspi *bs = spi_master_get_devdata(master);
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spi_master_suspend(master);
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clk_disable_unprepare(bs->clk);
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return 0;
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}
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static int bcm63xx_hsspi_resume(struct device *dev)
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{
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struct spi_master *master = dev_get_drvdata(dev);
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struct bcm63xx_hsspi *bs = spi_master_get_devdata(master);
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int ret;
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ret = clk_prepare_enable(bs->clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
spi_master_resume(master);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
static SIMPLE_DEV_PM_OPS(bcm63xx_hsspi_pm_ops, bcm63xx_hsspi_suspend,
|
|
bcm63xx_hsspi_resume);
|
|
|
|
static struct platform_driver bcm63xx_hsspi_driver = {
|
|
.driver = {
|
|
.name = "bcm63xx-hsspi",
|
|
.pm = &bcm63xx_hsspi_pm_ops,
|
|
},
|
|
.probe = bcm63xx_hsspi_probe,
|
|
.remove = bcm63xx_hsspi_remove,
|
|
};
|
|
|
|
module_platform_driver(bcm63xx_hsspi_driver);
|
|
|
|
MODULE_ALIAS("platform:bcm63xx_hsspi");
|
|
MODULE_DESCRIPTION("Broadcom BCM63xx High Speed SPI Controller driver");
|
|
MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
|
|
MODULE_LICENSE("GPL");
|