video: mmpdisp: add spi port in display controller

Add spi port support in mmp display controller. This port is from display
controller and for panel usage. This driver implemented and registered as
a spi master.

Signed-off-by: Zhou Zhu <[e-mail]>
Acked-by: Haojian Zhuang <[e-mail]>
Cc: Lisa Du <[e-mail]>
Cc: Guoqing Li <[e-mail]>
Cc: Florian Tobias Schandinat <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/video/mmp/hw/Kconfig

···
 		this controller is used on Marvell PXA910,
 		MMP2, MMP3, PXA988 chips
 
+config MMP_DISP_SPI
+	bool "mmp display controller spi port"
+	depends on MMP_DISP_CONTROLLER && SPI_MASTER
+	default y
+	help
+		Marvell MMP display hw controller spi port support
+		will register as a spi master for panel usage
+
 endif

drivers/video/mmp/hw/Makefile

···
 obj-$(CONFIG_MMP_DISP_CONTROLLER)  += mmp_ctrl.o
+obj-$(CONFIG_MMP_DISP_SPI)	   += mmp_spi.o

drivers/video/mmp/hw/mmp_ctrl.c

···
 		}
 	}
 
+#ifdef CONFIG_MMP_DISP_SPI
+	ret = lcd_spi_register(ctrl);
+	if (ret < 0)
+		goto failed_path_init;
+#endif
+
 	dev_info(ctrl->dev, "device init done\n");
 
 	return 0;

drivers/video/mmp/hw/mmp_ctrl.h

···
 		return NULL;
 	}
 }
+
+#ifdef CONFIG_MMP_DISP_SPI
+extern int lcd_spi_register(struct mmphw_ctrl *ctrl);
+#endif
 #endif	/* _MMP_CTRL_H_ */

drivers/video/mmp/hw/mmp_spi.c

···
+/*
+ * 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 <[e-mail]>
+ *          Lisa Du <[e-mail]>
+ *          Zhou Zhu <[e-mail]>
+ *
+ * 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;
+}