diff options
Diffstat (limited to 'drivers/video/mmp/hw/mmp_spi.c')
| -rw-r--r-- | drivers/video/mmp/hw/mmp_spi.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/video/mmp/hw/mmp_spi.c b/drivers/video/mmp/hw/mmp_spi.c new file mode 100644 index 000000000000..e62ca7bf0d5e --- /dev/null +++ b/drivers/video/mmp/hw/mmp_spi.c @@ -0,0 +1,180 @@ +/* + * linux/drivers/video/mmp/hw/mmp_spi.c + * using the spi in LCD controler for commands send + * + * Copyright (C) 2012 Marvell Technology Group Ltd. + * Authors: Guoqing Li <ligq@marvell.com> + * Lisa Du <cldu@marvell.com> + * Zhou Zhu <zzhu3@marvell.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + * + */ +#include <linux/errno.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/spi/spi.h> +#include "mmp_ctrl.h" + +/** + * spi_write - write command to the SPI port + * @data: can be 8/16/32-bit, MSB justified data to write. + * @len: data length. + * + * Wait bus transfer complete IRQ. + * The caller is expected to perform the necessary locking. + * + * Returns: + * %-ETIMEDOUT timeout occurred + * 0 success + */ +static inline int lcd_spi_write(struct spi_device *spi, u32 data) +{ + int timeout = 100000, isr, ret = 0; + u32 tmp; + void *reg_base = + *(void **)spi_master_get_devdata(spi->master); + + /* clear ISR */ + writel_relaxed(~SPI_IRQ_MASK, reg_base + SPU_IRQ_ISR); + + switch (spi->bits_per_word) { + case 8: + writel_relaxed((u8)data, reg_base + LCD_SPU_SPI_TXDATA); + break; + case 16: + writel_relaxed((u16)data, reg_base + LCD_SPU_SPI_TXDATA); + break; + case 32: + writel_relaxed((u32)data, reg_base + LCD_SPU_SPI_TXDATA); + break; + default: + dev_err(&spi->dev, "Wrong spi bit length\n"); + } + + /* SPI start to send command */ + tmp = readl_relaxed(reg_base + LCD_SPU_SPI_CTRL); + tmp &= ~CFG_SPI_START_MASK; + tmp |= CFG_SPI_START(1); + writel(tmp, reg_base + LCD_SPU_SPI_CTRL); + + isr = readl_relaxed(reg_base + SPU_IRQ_ISR); + while (!(isr & SPI_IRQ_ENA_MASK)) { + udelay(100); + isr = readl_relaxed(reg_base + SPU_IRQ_ISR); + if (!--timeout) { + ret = -ETIMEDOUT; + dev_err(&spi->dev, "spi cmd send time out\n"); + break; + } + } + + tmp = readl_relaxed(reg_base + LCD_SPU_SPI_CTRL); + tmp &= ~CFG_SPI_START_MASK; + tmp |= CFG_SPI_START(0); + writel_relaxed(tmp, reg_base + LCD_SPU_SPI_CTRL); + + writel_relaxed(~SPI_IRQ_MASK, reg_base + SPU_IRQ_ISR); + + return ret; +} + +static int lcd_spi_setup(struct spi_device *spi) +{ + void *reg_base = + *(void **)spi_master_get_devdata(spi->master); + u32 tmp; + + tmp = CFG_SCLKCNT(16) | + CFG_TXBITS(spi->bits_per_word) | + CFG_SPI_SEL(1) | CFG_SPI_ENA(1) | + CFG_SPI_3W4WB(1); + writel(tmp, reg_base + LCD_SPU_SPI_CTRL); + + /* + * After set mode it need a time to pull up the spi singals, + * or it would cause the wrong waveform when send spi command, + * especially on pxa910h + */ + tmp = readl_relaxed(reg_base + SPU_IOPAD_CONTROL); + if ((tmp & CFG_IOPADMODE_MASK) != IOPAD_DUMB18SPI) + writel_relaxed(IOPAD_DUMB18SPI | + (tmp & ~CFG_IOPADMODE_MASK), + reg_base + SPU_IOPAD_CONTROL); + udelay(20); + return 0; +} + +static int lcd_spi_one_transfer(struct spi_device *spi, struct spi_message *m) +{ + struct spi_transfer *t; + int i; + + list_for_each_entry(t, &m->transfers, transfer_list) { + switch (spi->bits_per_word) { + case 8: + for (i = 0; i < t->len; i++) + lcd_spi_write(spi, ((u8 *)t->tx_buf)[i]); + break; + case 16: + for (i = 0; i < t->len/2; i++) + lcd_spi_write(spi, ((u16 *)t->tx_buf)[i]); + break; + case 32: + for (i = 0; i < t->len/4; i++) + lcd_spi_write(spi, ((u32 *)t->tx_buf)[i]); + break; + default: + dev_err(&spi->dev, "Wrong spi bit length\n"); + } + } + + m->status = 0; + if (m->complete) + m->complete(m->context); + return 0; +} + +int lcd_spi_register(struct mmphw_ctrl *ctrl) +{ + struct spi_master *master; + void **p_regbase; + int err; + + master = spi_alloc_master(ctrl->dev, sizeof(void *)); + if (!master) { + dev_err(ctrl->dev, "unable to allocate SPI master\n"); + return -ENOMEM; + } + p_regbase = spi_master_get_devdata(master); + *p_regbase = ctrl->reg_base; + + /* set bus num to 5 to avoid conflict with other spi hosts */ + master->bus_num = 5; + master->num_chipselect = 1; + master->setup = lcd_spi_setup; + master->transfer = lcd_spi_one_transfer; + + err = spi_register_master(master); + if (err < 0) { + dev_err(ctrl->dev, "unable to register SPI master\n"); + spi_master_put(master); + return err; + } + + dev_info(&master->dev, "registered\n"); + + return 0; +} |