--- /dev/null
+/*
+ * 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;
+}
projects / firefly-linux-kernel-4.4.55.git / commitdiff