| /* |
| * Copyright (c) 2009 Nuvoton technology. |
| * Wan ZongShun <mcuos.com@gmail.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/spinlock.h> |
| #include <linux/workqueue.h> |
| #include <linux/interrupt.h> |
| #include <linux/delay.h> |
| #include <linux/errno.h> |
| #include <linux/err.h> |
| #include <linux/clk.h> |
| #include <linux/device.h> |
| #include <linux/platform_device.h> |
| #include <linux/gpio.h> |
| #include <linux/io.h> |
| #include <linux/slab.h> |
| |
| #include <linux/spi/spi.h> |
| #include <linux/spi/spi_bitbang.h> |
| |
| #include <linux/platform_data/spi-nuc900.h> |
| |
| /* usi registers offset */ |
| #define USI_CNT 0x00 |
| #define USI_DIV 0x04 |
| #define USI_SSR 0x08 |
| #define USI_RX0 0x10 |
| #define USI_TX0 0x10 |
| |
| /* usi register bit */ |
| #define ENINT (0x01 << 17) |
| #define ENFLG (0x01 << 16) |
| #define SLEEP (0x0f << 12) |
| #define TXNUM (0x03 << 8) |
| #define TXBITLEN (0x1f << 3) |
| #define TXNEG (0x01 << 2) |
| #define RXNEG (0x01 << 1) |
| #define LSB (0x01 << 10) |
| #define SELECTLEV (0x01 << 2) |
| #define SELECTPOL (0x01 << 31) |
| #define SELECTSLAVE 0x01 |
| #define GOBUSY 0x01 |
| |
| struct nuc900_spi { |
| struct spi_bitbang bitbang; |
| struct completion done; |
| void __iomem *regs; |
| int irq; |
| int len; |
| int count; |
| const unsigned char *tx; |
| unsigned char *rx; |
| struct clk *clk; |
| struct spi_master *master; |
| struct nuc900_spi_info *pdata; |
| spinlock_t lock; |
| }; |
| |
| static inline struct nuc900_spi *to_hw(struct spi_device *sdev) |
| { |
| return spi_master_get_devdata(sdev->master); |
| } |
| |
| static void nuc900_slave_select(struct spi_device *spi, unsigned int ssr) |
| { |
| struct nuc900_spi *hw = to_hw(spi); |
| unsigned int val; |
| unsigned int cs = spi->mode & SPI_CS_HIGH ? 1 : 0; |
| unsigned int cpol = spi->mode & SPI_CPOL ? 1 : 0; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_SSR); |
| |
| if (!cs) |
| val &= ~SELECTLEV; |
| else |
| val |= SELECTLEV; |
| |
| if (!ssr) |
| val &= ~SELECTSLAVE; |
| else |
| val |= SELECTSLAVE; |
| |
| __raw_writel(val, hw->regs + USI_SSR); |
| |
| val = __raw_readl(hw->regs + USI_CNT); |
| |
| if (!cpol) |
| val &= ~SELECTPOL; |
| else |
| val |= SELECTPOL; |
| |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| } |
| |
| static void nuc900_spi_chipsel(struct spi_device *spi, int value) |
| { |
| switch (value) { |
| case BITBANG_CS_INACTIVE: |
| nuc900_slave_select(spi, 0); |
| break; |
| |
| case BITBANG_CS_ACTIVE: |
| nuc900_slave_select(spi, 1); |
| break; |
| } |
| } |
| |
| static void nuc900_spi_setup_txnum(struct nuc900_spi *hw, unsigned int txnum) |
| { |
| unsigned int val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_CNT) & ~TXNUM; |
| |
| if (txnum) |
| val |= txnum << 0x08; |
| |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| |
| } |
| |
| static void nuc900_spi_setup_txbitlen(struct nuc900_spi *hw, |
| unsigned int txbitlen) |
| { |
| unsigned int val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_CNT) & ~TXBITLEN; |
| |
| val |= (txbitlen << 0x03); |
| |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| } |
| |
| static void nuc900_spi_gobusy(struct nuc900_spi *hw) |
| { |
| unsigned int val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_CNT); |
| |
| val |= GOBUSY; |
| |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| } |
| |
| static inline unsigned int hw_txbyte(struct nuc900_spi *hw, int count) |
| { |
| return hw->tx ? hw->tx[count] : 0; |
| } |
| |
| static int nuc900_spi_txrx(struct spi_device *spi, struct spi_transfer *t) |
| { |
| struct nuc900_spi *hw = to_hw(spi); |
| |
| hw->tx = t->tx_buf; |
| hw->rx = t->rx_buf; |
| hw->len = t->len; |
| hw->count = 0; |
| |
| __raw_writel(hw_txbyte(hw, 0x0), hw->regs + USI_TX0); |
| |
| nuc900_spi_gobusy(hw); |
| |
| wait_for_completion(&hw->done); |
| |
| return hw->count; |
| } |
| |
| static irqreturn_t nuc900_spi_irq(int irq, void *dev) |
| { |
| struct nuc900_spi *hw = dev; |
| unsigned int status; |
| unsigned int count = hw->count; |
| |
| status = __raw_readl(hw->regs + USI_CNT); |
| __raw_writel(status, hw->regs + USI_CNT); |
| |
| if (status & ENFLG) { |
| hw->count++; |
| |
| if (hw->rx) |
| hw->rx[count] = __raw_readl(hw->regs + USI_RX0); |
| count++; |
| |
| if (count < hw->len) { |
| __raw_writel(hw_txbyte(hw, count), hw->regs + USI_TX0); |
| nuc900_spi_gobusy(hw); |
| } else { |
| complete(&hw->done); |
| } |
| |
| return IRQ_HANDLED; |
| } |
| |
| complete(&hw->done); |
| return IRQ_HANDLED; |
| } |
| |
| static void nuc900_tx_edge(struct nuc900_spi *hw, unsigned int edge) |
| { |
| unsigned int val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_CNT); |
| |
| if (edge) |
| val |= TXNEG; |
| else |
| val &= ~TXNEG; |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| } |
| |
| static void nuc900_rx_edge(struct nuc900_spi *hw, unsigned int edge) |
| { |
| unsigned int val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_CNT); |
| |
| if (edge) |
| val |= RXNEG; |
| else |
| val &= ~RXNEG; |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| } |
| |
| static void nuc900_send_first(struct nuc900_spi *hw, unsigned int lsb) |
| { |
| unsigned int val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_CNT); |
| |
| if (lsb) |
| val |= LSB; |
| else |
| val &= ~LSB; |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| } |
| |
| static void nuc900_set_sleep(struct nuc900_spi *hw, unsigned int sleep) |
| { |
| unsigned int val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_CNT) & ~SLEEP; |
| |
| if (sleep) |
| val |= (sleep << 12); |
| |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| } |
| |
| static void nuc900_enable_int(struct nuc900_spi *hw) |
| { |
| unsigned int val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&hw->lock, flags); |
| |
| val = __raw_readl(hw->regs + USI_CNT); |
| |
| val |= ENINT; |
| |
| __raw_writel(val, hw->regs + USI_CNT); |
| |
| spin_unlock_irqrestore(&hw->lock, flags); |
| } |
| |
| static void nuc900_set_divider(struct nuc900_spi *hw) |
| { |
| __raw_writel(hw->pdata->divider, hw->regs + USI_DIV); |
| } |
| |
| static void nuc900_init_spi(struct nuc900_spi *hw) |
| { |
| clk_enable(hw->clk); |
| spin_lock_init(&hw->lock); |
| |
| nuc900_tx_edge(hw, hw->pdata->txneg); |
| nuc900_rx_edge(hw, hw->pdata->rxneg); |
| nuc900_send_first(hw, hw->pdata->lsb); |
| nuc900_set_sleep(hw, hw->pdata->sleep); |
| nuc900_spi_setup_txbitlen(hw, hw->pdata->txbitlen); |
| nuc900_spi_setup_txnum(hw, hw->pdata->txnum); |
| nuc900_set_divider(hw); |
| nuc900_enable_int(hw); |
| } |
| |
| static int nuc900_spi_probe(struct platform_device *pdev) |
| { |
| struct nuc900_spi *hw; |
| struct spi_master *master; |
| struct resource *res; |
| int err = 0; |
| |
| master = spi_alloc_master(&pdev->dev, sizeof(struct nuc900_spi)); |
| if (master == NULL) { |
| dev_err(&pdev->dev, "No memory for spi_master\n"); |
| return -ENOMEM; |
| } |
| |
| hw = spi_master_get_devdata(master); |
| hw->master = master; |
| hw->pdata = dev_get_platdata(&pdev->dev); |
| |
| if (hw->pdata == NULL) { |
| dev_err(&pdev->dev, "No platform data supplied\n"); |
| err = -ENOENT; |
| goto err_pdata; |
| } |
| |
| platform_set_drvdata(pdev, hw); |
| init_completion(&hw->done); |
| |
| master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; |
| if (hw->pdata->lsb) |
| master->mode_bits |= SPI_LSB_FIRST; |
| master->num_chipselect = hw->pdata->num_cs; |
| master->bus_num = hw->pdata->bus_num; |
| hw->bitbang.master = hw->master; |
| hw->bitbang.chipselect = nuc900_spi_chipsel; |
| hw->bitbang.txrx_bufs = nuc900_spi_txrx; |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| hw->regs = devm_ioremap_resource(&pdev->dev, res); |
| if (IS_ERR(hw->regs)) { |
| err = PTR_ERR(hw->regs); |
| goto err_pdata; |
| } |
| |
| hw->irq = platform_get_irq(pdev, 0); |
| if (hw->irq < 0) { |
| dev_err(&pdev->dev, "No IRQ specified\n"); |
| err = -ENOENT; |
| goto err_pdata; |
| } |
| |
| err = devm_request_irq(&pdev->dev, hw->irq, nuc900_spi_irq, 0, |
| pdev->name, hw); |
| if (err) { |
| dev_err(&pdev->dev, "Cannot claim IRQ\n"); |
| goto err_pdata; |
| } |
| |
| hw->clk = devm_clk_get(&pdev->dev, "spi"); |
| if (IS_ERR(hw->clk)) { |
| dev_err(&pdev->dev, "No clock for device\n"); |
| err = PTR_ERR(hw->clk); |
| goto err_pdata; |
| } |
| |
| mfp_set_groupg(&pdev->dev, NULL); |
| nuc900_init_spi(hw); |
| |
| err = spi_bitbang_start(&hw->bitbang); |
| if (err) { |
| dev_err(&pdev->dev, "Failed to register SPI master\n"); |
| goto err_register; |
| } |
| |
| return 0; |
| |
| err_register: |
| clk_disable(hw->clk); |
| err_pdata: |
| spi_master_put(hw->master); |
| return err; |
| } |
| |
| static int nuc900_spi_remove(struct platform_device *dev) |
| { |
| struct nuc900_spi *hw = platform_get_drvdata(dev); |
| |
| spi_bitbang_stop(&hw->bitbang); |
| clk_disable(hw->clk); |
| spi_master_put(hw->master); |
| return 0; |
| } |
| |
| static struct platform_driver nuc900_spi_driver = { |
| .probe = nuc900_spi_probe, |
| .remove = nuc900_spi_remove, |
| .driver = { |
| .name = "nuc900-spi", |
| .owner = THIS_MODULE, |
| }, |
| }; |
| module_platform_driver(nuc900_spi_driver); |
| |
| MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>"); |
| MODULE_DESCRIPTION("nuc900 spi driver!"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS("platform:nuc900-spi"); |