forked from Minki/linux
142168eba9
Add a driver for the High Speed SPI controller found on newer BCM63XX SoCs. It does feature some new modes like 3-wire or dual spi, but neither of it is currently implemented. Signed-off-by: Jonas Gorski <jogo@openwrt.org> Signed-off-by: Mark Brown <broonie@linaro.org>
485 lines
12 KiB
C
485 lines
12 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/workqueue.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_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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__raw_writel(0 << MODE_CTRL_PREPENDBYTE_CNT_SHIFT |
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2 << MODE_CTRL_MULTIDATA_WR_STRT_SHIFT |
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2 << MODE_CTRL_MULTIDATA_RD_STRT_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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init_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_request_and_ioremap(dev, res_mem);
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if (IS_ERR(regs))
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return PTR_ERR(regs);
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clk = 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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ret = -EINVAL;
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goto out_put_clk;
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}
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clk_prepare_enable(clk);
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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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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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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 = spi_register_master(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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out_put_clk:
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clk_put(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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spi_unregister_master(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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clk_put(bs->clk);
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return 0;
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}
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#ifdef CONFIG_PM
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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(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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clk_enable(bs->clk);
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spi_master_resume(master);
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return 0;
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}
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static const struct dev_pm_ops bcm63xx_hsspi_pm_ops = {
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.suspend = bcm63xx_hsspi_suspend,
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.resume = bcm63xx_hsspi_resume,
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};
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#define BCM63XX_HSSPI_PM_OPS (&bcm63xx_hsspi_pm_ops)
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#else
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#define BCM63XX_HSSPI_PM_OPS NULL
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#endif
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static struct platform_driver bcm63xx_hsspi_driver = {
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.driver = {
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.name = "bcm63xx-hsspi",
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.owner = THIS_MODULE,
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.pm = BCM63XX_HSSPI_PM_OPS,
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},
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.probe = bcm63xx_hsspi_probe,
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.remove = bcm63xx_hsspi_remove,
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};
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module_platform_driver(bcm63xx_hsspi_driver);
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MODULE_ALIAS("platform:bcm63xx_hsspi");
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MODULE_DESCRIPTION("Broadcom BCM63xx High Speed SPI Controller driver");
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MODULE_AUTHOR("Jonas Gorski <jogo@openwrt.org>");
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MODULE_LICENSE("GPL");
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