359 lines
9.0 KiB
C
359 lines
9.0 KiB
C
/*
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* Copyright (c) 2014 MediaTek Inc.
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* Author: Jie Qiu <jie.qiu@mediatek.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/time.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/platform_device.h>
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#include <linux/clk.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/iopoll.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <linux/of_platform.h>
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#define SIF1_CLOK (288)
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#define DDC_DDCMCTL0 (0x0)
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#define DDCM_ODRAIN BIT(31)
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#define DDCM_CLK_DIV_OFFSET (16)
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#define DDCM_CLK_DIV_MASK (0xfff << 16)
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#define DDCM_CS_STATUS BIT(4)
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#define DDCM_SCL_STATE BIT(3)
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#define DDCM_SDA_STATE BIT(2)
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#define DDCM_SM0EN BIT(1)
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#define DDCM_SCL_STRECH BIT(0)
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#define DDC_DDCMCTL1 (0x4)
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#define DDCM_ACK_OFFSET (16)
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#define DDCM_ACK_MASK (0xff << 16)
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#define DDCM_PGLEN_OFFSET (8)
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#define DDCM_PGLEN_MASK (0x7 << 8)
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#define DDCM_SIF_MODE_OFFSET (4)
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#define DDCM_SIF_MODE_MASK (0x7 << 4)
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#define DDCM_START (0x1)
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#define DDCM_WRITE_DATA (0x2)
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#define DDCM_STOP (0x3)
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#define DDCM_READ_DATA_NO_ACK (0x4)
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#define DDCM_READ_DATA_ACK (0x5)
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#define DDCM_TRI BIT(0)
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#define DDC_DDCMD0 (0x8)
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#define DDCM_DATA3 (0xff << 24)
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#define DDCM_DATA2 (0xff << 16)
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#define DDCM_DATA1 (0xff << 8)
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#define DDCM_DATA0 (0xff << 0)
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#define DDC_DDCMD1 (0xc)
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#define DDCM_DATA7 (0xff << 24)
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#define DDCM_DATA6 (0xff << 16)
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#define DDCM_DATA5 (0xff << 8)
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#define DDCM_DATA4 (0xff << 0)
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struct mtk_hdmi_ddc {
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struct i2c_adapter adap;
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struct clk *clk;
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void __iomem *regs;
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};
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static inline void sif_set_bit(struct mtk_hdmi_ddc *ddc, unsigned int offset,
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unsigned int val)
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{
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writel(readl(ddc->regs + offset) | val, ddc->regs + offset);
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}
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static inline void sif_clr_bit(struct mtk_hdmi_ddc *ddc, unsigned int offset,
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unsigned int val)
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{
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writel(readl(ddc->regs + offset) & ~val, ddc->regs + offset);
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}
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static inline bool sif_bit_is_set(struct mtk_hdmi_ddc *ddc, unsigned int offset,
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unsigned int val)
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{
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return (readl(ddc->regs + offset) & val) == val;
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}
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static inline void sif_write_mask(struct mtk_hdmi_ddc *ddc, unsigned int offset,
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unsigned int mask, unsigned int shift,
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unsigned int val)
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{
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unsigned int tmp;
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tmp = readl(ddc->regs + offset);
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tmp &= ~mask;
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tmp |= (val << shift) & mask;
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writel(tmp, ddc->regs + offset);
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}
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static inline unsigned int sif_read_mask(struct mtk_hdmi_ddc *ddc,
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unsigned int offset, unsigned int mask,
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unsigned int shift)
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{
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return (readl(ddc->regs + offset) & mask) >> shift;
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}
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static void ddcm_trigger_mode(struct mtk_hdmi_ddc *ddc, int mode)
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{
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u32 val;
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sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_SIF_MODE_MASK,
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DDCM_SIF_MODE_OFFSET, mode);
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sif_set_bit(ddc, DDC_DDCMCTL1, DDCM_TRI);
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readl_poll_timeout(ddc->regs + DDC_DDCMCTL1, val,
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(val & DDCM_TRI) != DDCM_TRI, 4, 20000);
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}
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static int mtk_hdmi_ddc_read_msg(struct mtk_hdmi_ddc *ddc, struct i2c_msg *msg)
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{
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struct device *dev = ddc->adap.dev.parent;
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u32 remain_count, ack_count, ack_final, read_count, temp_count;
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u32 index = 0;
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u32 ack;
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int i;
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ddcm_trigger_mode(ddc, DDCM_START);
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sif_write_mask(ddc, DDC_DDCMD0, 0xff, 0, (msg->addr << 1) | 0x01);
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sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK, DDCM_PGLEN_OFFSET,
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0x00);
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ddcm_trigger_mode(ddc, DDCM_WRITE_DATA);
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ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK, DDCM_ACK_OFFSET);
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dev_dbg(dev, "ack = 0x%x\n", ack);
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if (ack != 0x01) {
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dev_err(dev, "i2c ack err!\n");
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return -ENXIO;
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}
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remain_count = msg->len;
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ack_count = (msg->len - 1) / 8;
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ack_final = 0;
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while (remain_count > 0) {
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if (ack_count > 0) {
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read_count = 8;
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ack_final = 0;
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ack_count--;
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} else {
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read_count = remain_count;
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ack_final = 1;
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}
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sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK,
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DDCM_PGLEN_OFFSET, read_count - 1);
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ddcm_trigger_mode(ddc, (ack_final == 1) ?
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DDCM_READ_DATA_NO_ACK :
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DDCM_READ_DATA_ACK);
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ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK,
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DDCM_ACK_OFFSET);
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temp_count = 0;
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while (((ack & (1 << temp_count)) != 0) && (temp_count < 8))
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temp_count++;
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if (((ack_final == 1) && (temp_count != (read_count - 1))) ||
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((ack_final == 0) && (temp_count != read_count))) {
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dev_err(dev, "Address NACK! ACK(0x%x)\n", ack);
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break;
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}
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for (i = read_count; i >= 1; i--) {
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int shift;
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int offset;
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if (i > 4) {
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offset = DDC_DDCMD1;
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shift = (i - 5) * 8;
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} else {
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offset = DDC_DDCMD0;
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shift = (i - 1) * 8;
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}
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msg->buf[index + i - 1] = sif_read_mask(ddc, offset,
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0xff << shift,
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shift);
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}
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remain_count -= read_count;
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index += read_count;
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}
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return 0;
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}
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static int mtk_hdmi_ddc_write_msg(struct mtk_hdmi_ddc *ddc, struct i2c_msg *msg)
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{
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struct device *dev = ddc->adap.dev.parent;
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u32 ack;
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ddcm_trigger_mode(ddc, DDCM_START);
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sif_write_mask(ddc, DDC_DDCMD0, DDCM_DATA0, 0, msg->addr << 1);
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sif_write_mask(ddc, DDC_DDCMD0, DDCM_DATA1, 8, msg->buf[0]);
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sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK, DDCM_PGLEN_OFFSET,
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0x1);
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ddcm_trigger_mode(ddc, DDCM_WRITE_DATA);
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ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK, DDCM_ACK_OFFSET);
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dev_dbg(dev, "ack = %d\n", ack);
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if (ack != 0x03) {
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dev_err(dev, "i2c ack err!\n");
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return -EIO;
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}
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return 0;
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}
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static int mtk_hdmi_ddc_xfer(struct i2c_adapter *adapter,
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struct i2c_msg *msgs, int num)
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{
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struct mtk_hdmi_ddc *ddc = adapter->algo_data;
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struct device *dev = adapter->dev.parent;
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int ret;
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int i;
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if (!ddc) {
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dev_err(dev, "invalid arguments\n");
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return -EINVAL;
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}
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sif_set_bit(ddc, DDC_DDCMCTL0, DDCM_SCL_STRECH);
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sif_set_bit(ddc, DDC_DDCMCTL0, DDCM_SM0EN);
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sif_clr_bit(ddc, DDC_DDCMCTL0, DDCM_ODRAIN);
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if (sif_bit_is_set(ddc, DDC_DDCMCTL1, DDCM_TRI)) {
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dev_err(dev, "ddc line is busy!\n");
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return -EBUSY;
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}
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sif_write_mask(ddc, DDC_DDCMCTL0, DDCM_CLK_DIV_MASK,
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DDCM_CLK_DIV_OFFSET, SIF1_CLOK);
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for (i = 0; i < num; i++) {
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struct i2c_msg *msg = &msgs[i];
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dev_dbg(dev, "i2c msg, adr:0x%x, flags:%d, len :0x%x\n",
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msg->addr, msg->flags, msg->len);
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if (msg->flags & I2C_M_RD)
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ret = mtk_hdmi_ddc_read_msg(ddc, msg);
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else
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ret = mtk_hdmi_ddc_write_msg(ddc, msg);
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if (ret < 0)
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goto xfer_end;
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}
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ddcm_trigger_mode(ddc, DDCM_STOP);
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return i;
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xfer_end:
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ddcm_trigger_mode(ddc, DDCM_STOP);
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dev_err(dev, "ddc failed!\n");
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return ret;
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}
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static u32 mtk_hdmi_ddc_func(struct i2c_adapter *adapter)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
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}
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static const struct i2c_algorithm mtk_hdmi_ddc_algorithm = {
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.master_xfer = mtk_hdmi_ddc_xfer,
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.functionality = mtk_hdmi_ddc_func,
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};
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static int mtk_hdmi_ddc_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct mtk_hdmi_ddc *ddc;
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struct resource *mem;
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int ret;
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ddc = devm_kzalloc(dev, sizeof(struct mtk_hdmi_ddc), GFP_KERNEL);
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if (!ddc)
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return -ENOMEM;
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ddc->clk = devm_clk_get(dev, "ddc-i2c");
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if (IS_ERR(ddc->clk)) {
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dev_err(dev, "get ddc_clk failed: %p ,\n", ddc->clk);
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return PTR_ERR(ddc->clk);
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}
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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ddc->regs = devm_ioremap_resource(&pdev->dev, mem);
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if (IS_ERR(ddc->regs))
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return PTR_ERR(ddc->regs);
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ret = clk_prepare_enable(ddc->clk);
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if (ret) {
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dev_err(dev, "enable ddc clk failed!\n");
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return ret;
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}
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strlcpy(ddc->adap.name, "mediatek-hdmi-ddc", sizeof(ddc->adap.name));
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ddc->adap.owner = THIS_MODULE;
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ddc->adap.class = I2C_CLASS_DDC;
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ddc->adap.algo = &mtk_hdmi_ddc_algorithm;
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ddc->adap.retries = 3;
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ddc->adap.dev.of_node = dev->of_node;
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ddc->adap.algo_data = ddc;
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ddc->adap.dev.parent = &pdev->dev;
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ret = i2c_add_adapter(&ddc->adap);
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if (ret < 0) {
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dev_err(dev, "failed to add bus to i2c core\n");
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goto err_clk_disable;
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}
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platform_set_drvdata(pdev, ddc);
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dev_dbg(dev, "ddc->adap: %p\n", &ddc->adap);
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dev_dbg(dev, "ddc->clk: %p\n", ddc->clk);
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dev_dbg(dev, "physical adr: %pa, end: %pa\n", &mem->start,
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&mem->end);
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return 0;
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err_clk_disable:
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clk_disable_unprepare(ddc->clk);
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return ret;
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}
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static int mtk_hdmi_ddc_remove(struct platform_device *pdev)
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{
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struct mtk_hdmi_ddc *ddc = platform_get_drvdata(pdev);
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i2c_del_adapter(&ddc->adap);
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clk_disable_unprepare(ddc->clk);
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return 0;
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}
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static const struct of_device_id mtk_hdmi_ddc_match[] = {
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{ .compatible = "mediatek,mt8173-hdmi-ddc", },
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{},
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};
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struct platform_driver mtk_hdmi_ddc_driver = {
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.probe = mtk_hdmi_ddc_probe,
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.remove = mtk_hdmi_ddc_remove,
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.driver = {
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.name = "mediatek-hdmi-ddc",
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.of_match_table = mtk_hdmi_ddc_match,
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},
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};
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MODULE_AUTHOR("Jie Qiu <jie.qiu@mediatek.com>");
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MODULE_DESCRIPTION("MediaTek HDMI DDC Driver");
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MODULE_LICENSE("GPL v2");
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