diff options
Diffstat (limited to 'drivers/gpu/drm/mediatek/mtk_hdmi_ddc.c')
| -rw-r--r-- | drivers/gpu/drm/mediatek/mtk_hdmi_ddc.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi_ddc.c b/drivers/gpu/drm/mediatek/mtk_hdmi_ddc.c new file mode 100644 index 000000000000..33c9e1bdb114 --- /dev/null +++ b/drivers/gpu/drm/mediatek/mtk_hdmi_ddc.c @@ -0,0 +1,358 @@ +/* + * Copyright (c) 2014 MediaTek Inc. + * Author: Jie Qiu <jie.qiu@mediatek.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. + * + * 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. + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/time.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> + +#define SIF1_CLOK (288) +#define DDC_DDCMCTL0 (0x0) +#define DDCM_ODRAIN BIT(31) +#define DDCM_CLK_DIV_OFFSET (16) +#define DDCM_CLK_DIV_MASK (0xfff << 16) +#define DDCM_CS_STATUS BIT(4) +#define DDCM_SCL_STATE BIT(3) +#define DDCM_SDA_STATE BIT(2) +#define DDCM_SM0EN BIT(1) +#define DDCM_SCL_STRECH BIT(0) +#define DDC_DDCMCTL1 (0x4) +#define DDCM_ACK_OFFSET (16) +#define DDCM_ACK_MASK (0xff << 16) +#define DDCM_PGLEN_OFFSET (8) +#define DDCM_PGLEN_MASK (0x7 << 8) +#define DDCM_SIF_MODE_OFFSET (4) +#define DDCM_SIF_MODE_MASK (0x7 << 4) +#define DDCM_START (0x1) +#define DDCM_WRITE_DATA (0x2) +#define DDCM_STOP (0x3) +#define DDCM_READ_DATA_NO_ACK (0x4) +#define DDCM_READ_DATA_ACK (0x5) +#define DDCM_TRI BIT(0) +#define DDC_DDCMD0 (0x8) +#define DDCM_DATA3 (0xff << 24) +#define DDCM_DATA2 (0xff << 16) +#define DDCM_DATA1 (0xff << 8) +#define DDCM_DATA0 (0xff << 0) +#define DDC_DDCMD1 (0xc) +#define DDCM_DATA7 (0xff << 24) +#define DDCM_DATA6 (0xff << 16) +#define DDCM_DATA5 (0xff << 8) +#define DDCM_DATA4 (0xff << 0) + +struct mtk_hdmi_ddc { + struct i2c_adapter adap; + struct clk *clk; + void __iomem *regs; +}; + +static inline void sif_set_bit(struct mtk_hdmi_ddc *ddc, unsigned int offset, + unsigned int val) +{ + writel(readl(ddc->regs + offset) | val, ddc->regs + offset); +} + +static inline void sif_clr_bit(struct mtk_hdmi_ddc *ddc, unsigned int offset, + unsigned int val) +{ + writel(readl(ddc->regs + offset) & ~val, ddc->regs + offset); +} + +static inline bool sif_bit_is_set(struct mtk_hdmi_ddc *ddc, unsigned int offset, + unsigned int val) +{ + return (readl(ddc->regs + offset) & val) == val; +} + +static inline void sif_write_mask(struct mtk_hdmi_ddc *ddc, unsigned int offset, + unsigned int mask, unsigned int shift, + unsigned int val) +{ + unsigned int tmp; + + tmp = readl(ddc->regs + offset); + tmp &= ~mask; + tmp |= (val << shift) & mask; + writel(tmp, ddc->regs + offset); +} + +static inline unsigned int sif_read_mask(struct mtk_hdmi_ddc *ddc, + unsigned int offset, unsigned int mask, + unsigned int shift) +{ + return (readl(ddc->regs + offset) & mask) >> shift; +} + +static void ddcm_trigger_mode(struct mtk_hdmi_ddc *ddc, int mode) +{ + u32 val; + + sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_SIF_MODE_MASK, + DDCM_SIF_MODE_OFFSET, mode); + sif_set_bit(ddc, DDC_DDCMCTL1, DDCM_TRI); + readl_poll_timeout(ddc->regs + DDC_DDCMCTL1, val, + (val & DDCM_TRI) != DDCM_TRI, 4, 20000); +} + +static int mtk_hdmi_ddc_read_msg(struct mtk_hdmi_ddc *ddc, struct i2c_msg *msg) +{ + struct device *dev = ddc->adap.dev.parent; + u32 remain_count, ack_count, ack_final, read_count, temp_count; + u32 index = 0; + u32 ack; + int i; + + ddcm_trigger_mode(ddc, DDCM_START); + sif_write_mask(ddc, DDC_DDCMD0, 0xff, 0, (msg->addr << 1) | 0x01); + sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK, DDCM_PGLEN_OFFSET, + 0x00); + ddcm_trigger_mode(ddc, DDCM_WRITE_DATA); + ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK, DDCM_ACK_OFFSET); + dev_dbg(dev, "ack = 0x%x\n", ack); + if (ack != 0x01) { + dev_err(dev, "i2c ack err!\n"); + return -ENXIO; + } + + remain_count = msg->len; + ack_count = (msg->len - 1) / 8; + ack_final = 0; + + while (remain_count > 0) { + if (ack_count > 0) { + read_count = 8; + ack_final = 0; + ack_count--; + } else { + read_count = remain_count; + ack_final = 1; + } + + sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK, + DDCM_PGLEN_OFFSET, read_count - 1); + ddcm_trigger_mode(ddc, (ack_final == 1) ? + DDCM_READ_DATA_NO_ACK : + DDCM_READ_DATA_ACK); + + ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK, + DDCM_ACK_OFFSET); + temp_count = 0; + while (((ack & (1 << temp_count)) != 0) && (temp_count < 8)) + temp_count++; + if (((ack_final == 1) && (temp_count != (read_count - 1))) || + ((ack_final == 0) && (temp_count != read_count))) { + dev_err(dev, "Address NACK! ACK(0x%x)\n", ack); + break; + } + + for (i = read_count; i >= 1; i--) { + int shift; + int offset; + + if (i > 4) { + offset = DDC_DDCMD1; + shift = (i - 5) * 8; + } else { + offset = DDC_DDCMD0; + shift = (i - 1) * 8; + } + + msg->buf[index + i - 1] = sif_read_mask(ddc, offset, + 0xff << shift, + shift); + } + + remain_count -= read_count; + index += read_count; + } + + return 0; +} + +static int mtk_hdmi_ddc_write_msg(struct mtk_hdmi_ddc *ddc, struct i2c_msg *msg) +{ + struct device *dev = ddc->adap.dev.parent; + u32 ack; + + ddcm_trigger_mode(ddc, DDCM_START); + sif_write_mask(ddc, DDC_DDCMD0, DDCM_DATA0, 0, msg->addr << 1); + sif_write_mask(ddc, DDC_DDCMD0, DDCM_DATA1, 8, msg->buf[0]); + sif_write_mask(ddc, DDC_DDCMCTL1, DDCM_PGLEN_MASK, DDCM_PGLEN_OFFSET, + 0x1); + ddcm_trigger_mode(ddc, DDCM_WRITE_DATA); + + ack = sif_read_mask(ddc, DDC_DDCMCTL1, DDCM_ACK_MASK, DDCM_ACK_OFFSET); + dev_dbg(dev, "ack = %d\n", ack); + + if (ack != 0x03) { + dev_err(dev, "i2c ack err!\n"); + return -EIO; + } + + return 0; +} + +static int mtk_hdmi_ddc_xfer(struct i2c_adapter *adapter, + struct i2c_msg *msgs, int num) +{ + struct mtk_hdmi_ddc *ddc = adapter->algo_data; + struct device *dev = adapter->dev.parent; + int ret; + int i; + + if (!ddc) { + dev_err(dev, "invalid arguments\n"); + return -EINVAL; + } + + sif_set_bit(ddc, DDC_DDCMCTL0, DDCM_SCL_STRECH); + sif_set_bit(ddc, DDC_DDCMCTL0, DDCM_SM0EN); + sif_clr_bit(ddc, DDC_DDCMCTL0, DDCM_ODRAIN); + + if (sif_bit_is_set(ddc, DDC_DDCMCTL1, DDCM_TRI)) { + dev_err(dev, "ddc line is busy!\n"); + return -EBUSY; + } + + sif_write_mask(ddc, DDC_DDCMCTL0, DDCM_CLK_DIV_MASK, + DDCM_CLK_DIV_OFFSET, SIF1_CLOK); + + for (i = 0; i < num; i++) { + struct i2c_msg *msg = &msgs[i]; + + dev_dbg(dev, "i2c msg, adr:0x%x, flags:%d, len :0x%x\n", + msg->addr, msg->flags, msg->len); + + if (msg->flags & I2C_M_RD) + ret = mtk_hdmi_ddc_read_msg(ddc, msg); + else + ret = mtk_hdmi_ddc_write_msg(ddc, msg); + if (ret < 0) + goto xfer_end; + } + + ddcm_trigger_mode(ddc, DDCM_STOP); + + return i; + +xfer_end: + ddcm_trigger_mode(ddc, DDCM_STOP); + dev_err(dev, "ddc failed!\n"); + return ret; +} + +static u32 mtk_hdmi_ddc_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm mtk_hdmi_ddc_algorithm = { + .master_xfer = mtk_hdmi_ddc_xfer, + .functionality = mtk_hdmi_ddc_func, +}; + +static int mtk_hdmi_ddc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mtk_hdmi_ddc *ddc; + struct resource *mem; + int ret; + + ddc = devm_kzalloc(dev, sizeof(struct mtk_hdmi_ddc), GFP_KERNEL); + if (!ddc) + return -ENOMEM; + + ddc->clk = devm_clk_get(dev, "ddc-i2c"); + if (IS_ERR(ddc->clk)) { + dev_err(dev, "get ddc_clk failed: %p ,\n", ddc->clk); + return PTR_ERR(ddc->clk); + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + ddc->regs = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(ddc->regs)) + return PTR_ERR(ddc->regs); + + ret = clk_prepare_enable(ddc->clk); + if (ret) { + dev_err(dev, "enable ddc clk failed!\n"); + return ret; + } + + strlcpy(ddc->adap.name, "mediatek-hdmi-ddc", sizeof(ddc->adap.name)); + ddc->adap.owner = THIS_MODULE; + ddc->adap.class = I2C_CLASS_DDC; + ddc->adap.algo = &mtk_hdmi_ddc_algorithm; + ddc->adap.retries = 3; + ddc->adap.dev.of_node = dev->of_node; + ddc->adap.algo_data = ddc; + ddc->adap.dev.parent = &pdev->dev; + + ret = i2c_add_adapter(&ddc->adap); + if (ret < 0) { + dev_err(dev, "failed to add bus to i2c core\n"); + goto err_clk_disable; + } + + platform_set_drvdata(pdev, ddc); + + dev_dbg(dev, "ddc->adap: %p\n", &ddc->adap); + dev_dbg(dev, "ddc->clk: %p\n", ddc->clk); + dev_dbg(dev, "physical adr: %pa, end: %pa\n", &mem->start, + &mem->end); + + return 0; + +err_clk_disable: + clk_disable_unprepare(ddc->clk); + return ret; +} + +static int mtk_hdmi_ddc_remove(struct platform_device *pdev) +{ + struct mtk_hdmi_ddc *ddc = platform_get_drvdata(pdev); + + i2c_del_adapter(&ddc->adap); + clk_disable_unprepare(ddc->clk); + + return 0; +} + +static const struct of_device_id mtk_hdmi_ddc_match[] = { + { .compatible = "mediatek,mt8173-hdmi-ddc", }, + {}, +}; + +struct platform_driver mtk_hdmi_ddc_driver = { + .probe = mtk_hdmi_ddc_probe, + .remove = mtk_hdmi_ddc_remove, + .driver = { + .name = "mediatek-hdmi-ddc", + .of_match_table = mtk_hdmi_ddc_match, + }, +}; + +MODULE_AUTHOR("Jie Qiu <jie.qiu@mediatek.com>"); +MODULE_DESCRIPTION("MediaTek HDMI DDC Driver"); +MODULE_LICENSE("GPL v2"); |