| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C) 2016 Maxime Ripard <maxime.ripard@free-electrons.com> |
| * Copyright (C) 2017 Jonathan Liu <net147@gmail.com> |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/i2c.h> |
| #include <linux/iopoll.h> |
| |
| #include "sun4i_hdmi.h" |
| |
| #define SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK ( \ |
| SUN4I_HDMI_DDC_INT_STATUS_ILLEGAL_FIFO_OPERATION | \ |
| SUN4I_HDMI_DDC_INT_STATUS_DDC_RX_FIFO_UNDERFLOW | \ |
| SUN4I_HDMI_DDC_INT_STATUS_DDC_TX_FIFO_OVERFLOW | \ |
| SUN4I_HDMI_DDC_INT_STATUS_ARBITRATION_ERROR | \ |
| SUN4I_HDMI_DDC_INT_STATUS_ACK_ERROR | \ |
| SUN4I_HDMI_DDC_INT_STATUS_BUS_ERROR \ |
| ) |
| |
| /* FIFO request bit is set when FIFO level is above RX_THRESHOLD during read */ |
| #define RX_THRESHOLD SUN4I_HDMI_DDC_FIFO_CTRL_RX_THRES_MAX |
| |
| static int fifo_transfer(struct sun4i_hdmi *hdmi, u8 *buf, int len, bool read) |
| { |
| /* |
| * 1 byte takes 9 clock cycles (8 bits + 1 ACK) = 90 us for 100 kHz |
| * clock. As clock rate is fixed, just round it up to 100 us. |
| */ |
| const unsigned long byte_time_ns = 100; |
| const u32 mask = SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK | |
| SUN4I_HDMI_DDC_INT_STATUS_FIFO_REQUEST | |
| SUN4I_HDMI_DDC_INT_STATUS_TRANSFER_COMPLETE; |
| u32 reg; |
| /* |
| * If threshold is inclusive, then the FIFO may only have |
| * RX_THRESHOLD number of bytes, instead of RX_THRESHOLD + 1. |
| */ |
| int read_len = RX_THRESHOLD + |
| (hdmi->variant->ddc_fifo_thres_incl ? 0 : 1); |
| |
| /* |
| * Limit transfer length by FIFO threshold or FIFO size. |
| * For TX the threshold is for an empty FIFO. |
| */ |
| len = min_t(int, len, read ? read_len : SUN4I_HDMI_DDC_FIFO_SIZE); |
| |
| /* Wait until error, FIFO request bit set or transfer complete */ |
| if (regmap_field_read_poll_timeout(hdmi->field_ddc_int_status, reg, |
| reg & mask, len * byte_time_ns, |
| 100000)) |
| return -ETIMEDOUT; |
| |
| if (reg & SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK) |
| return -EIO; |
| |
| if (read) |
| ioread8_rep(hdmi->base + hdmi->variant->ddc_fifo_reg, buf, len); |
| else |
| iowrite8_rep(hdmi->base + hdmi->variant->ddc_fifo_reg, buf, len); |
| |
| /* Clear FIFO request bit by forcing a write to that bit */ |
| regmap_field_force_write(hdmi->field_ddc_int_status, |
| SUN4I_HDMI_DDC_INT_STATUS_FIFO_REQUEST); |
| |
| return len; |
| } |
| |
| static int xfer_msg(struct sun4i_hdmi *hdmi, struct i2c_msg *msg) |
| { |
| int i, len; |
| u32 reg; |
| |
| /* Set FIFO direction */ |
| if (hdmi->variant->ddc_fifo_has_dir) { |
| reg = readl(hdmi->base + SUN4I_HDMI_DDC_CTRL_REG); |
| reg &= ~SUN4I_HDMI_DDC_CTRL_FIFO_DIR_MASK; |
| reg |= (msg->flags & I2C_M_RD) ? |
| SUN4I_HDMI_DDC_CTRL_FIFO_DIR_READ : |
| SUN4I_HDMI_DDC_CTRL_FIFO_DIR_WRITE; |
| writel(reg, hdmi->base + SUN4I_HDMI_DDC_CTRL_REG); |
| } |
| |
| /* Clear address register (not cleared by soft reset) */ |
| regmap_field_write(hdmi->field_ddc_addr_reg, 0); |
| |
| /* Set I2C address */ |
| regmap_field_write(hdmi->field_ddc_slave_addr, msg->addr); |
| |
| /* |
| * Set FIFO RX/TX thresholds and clear FIFO |
| * |
| * If threshold is inclusive, we can set the TX threshold to |
| * 0 instead of 1. |
| */ |
| regmap_field_write(hdmi->field_ddc_fifo_tx_thres, |
| hdmi->variant->ddc_fifo_thres_incl ? 0 : 1); |
| regmap_field_write(hdmi->field_ddc_fifo_rx_thres, RX_THRESHOLD); |
| regmap_field_write(hdmi->field_ddc_fifo_clear, 1); |
| if (regmap_field_read_poll_timeout(hdmi->field_ddc_fifo_clear, |
| reg, !reg, 100, 2000)) |
| return -EIO; |
| |
| /* Set transfer length */ |
| regmap_field_write(hdmi->field_ddc_byte_count, msg->len); |
| |
| /* Set command */ |
| regmap_field_write(hdmi->field_ddc_cmd, |
| msg->flags & I2C_M_RD ? |
| SUN4I_HDMI_DDC_CMD_IMPLICIT_READ : |
| SUN4I_HDMI_DDC_CMD_IMPLICIT_WRITE); |
| |
| /* Clear interrupt status bits by forcing a write */ |
| regmap_field_force_write(hdmi->field_ddc_int_status, |
| SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK | |
| SUN4I_HDMI_DDC_INT_STATUS_FIFO_REQUEST | |
| SUN4I_HDMI_DDC_INT_STATUS_TRANSFER_COMPLETE); |
| |
| /* Start command */ |
| regmap_field_write(hdmi->field_ddc_start, 1); |
| |
| /* Transfer bytes */ |
| for (i = 0; i < msg->len; i += len) { |
| len = fifo_transfer(hdmi, msg->buf + i, msg->len - i, |
| msg->flags & I2C_M_RD); |
| if (len <= 0) |
| return len; |
| } |
| |
| /* Wait for command to finish */ |
| if (regmap_field_read_poll_timeout(hdmi->field_ddc_start, |
| reg, !reg, 100, 100000)) |
| return -EIO; |
| |
| /* Check for errors */ |
| regmap_field_read(hdmi->field_ddc_int_status, ®); |
| if ((reg & SUN4I_HDMI_DDC_INT_STATUS_ERROR_MASK) || |
| !(reg & SUN4I_HDMI_DDC_INT_STATUS_TRANSFER_COMPLETE)) { |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| static int sun4i_hdmi_i2c_xfer(struct i2c_adapter *adap, |
| struct i2c_msg *msgs, int num) |
| { |
| struct sun4i_hdmi *hdmi = i2c_get_adapdata(adap); |
| u32 reg; |
| int err, i, ret = num; |
| |
| for (i = 0; i < num; i++) { |
| if (!msgs[i].len) |
| return -EINVAL; |
| if (msgs[i].len > SUN4I_HDMI_DDC_BYTE_COUNT_MAX) |
| return -EINVAL; |
| } |
| |
| /* DDC clock needs to be enabled for the module to work */ |
| clk_prepare_enable(hdmi->ddc_clk); |
| clk_set_rate(hdmi->ddc_clk, 100000); |
| |
| /* Reset I2C controller */ |
| regmap_field_write(hdmi->field_ddc_en, 1); |
| regmap_field_write(hdmi->field_ddc_reset, 1); |
| if (regmap_field_read_poll_timeout(hdmi->field_ddc_reset, |
| reg, !reg, 100, 2000)) { |
| clk_disable_unprepare(hdmi->ddc_clk); |
| return -EIO; |
| } |
| |
| regmap_field_write(hdmi->field_ddc_sck_en, 1); |
| regmap_field_write(hdmi->field_ddc_sda_en, 1); |
| |
| for (i = 0; i < num; i++) { |
| err = xfer_msg(hdmi, &msgs[i]); |
| if (err) { |
| ret = err; |
| break; |
| } |
| } |
| |
| clk_disable_unprepare(hdmi->ddc_clk); |
| return ret; |
| } |
| |
| static u32 sun4i_hdmi_i2c_func(struct i2c_adapter *adap) |
| { |
| return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; |
| } |
| |
| static const struct i2c_algorithm sun4i_hdmi_i2c_algorithm = { |
| .master_xfer = sun4i_hdmi_i2c_xfer, |
| .functionality = sun4i_hdmi_i2c_func, |
| }; |
| |
| static int sun4i_hdmi_init_regmap_fields(struct sun4i_hdmi *hdmi) |
| { |
| hdmi->field_ddc_en = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_en); |
| if (IS_ERR(hdmi->field_ddc_en)) |
| return PTR_ERR(hdmi->field_ddc_en); |
| |
| hdmi->field_ddc_start = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_start); |
| if (IS_ERR(hdmi->field_ddc_start)) |
| return PTR_ERR(hdmi->field_ddc_start); |
| |
| hdmi->field_ddc_reset = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_reset); |
| if (IS_ERR(hdmi->field_ddc_reset)) |
| return PTR_ERR(hdmi->field_ddc_reset); |
| |
| hdmi->field_ddc_addr_reg = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_addr_reg); |
| if (IS_ERR(hdmi->field_ddc_addr_reg)) |
| return PTR_ERR(hdmi->field_ddc_addr_reg); |
| |
| hdmi->field_ddc_slave_addr = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_slave_addr); |
| if (IS_ERR(hdmi->field_ddc_slave_addr)) |
| return PTR_ERR(hdmi->field_ddc_slave_addr); |
| |
| hdmi->field_ddc_int_mask = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_int_mask); |
| if (IS_ERR(hdmi->field_ddc_int_mask)) |
| return PTR_ERR(hdmi->field_ddc_int_mask); |
| |
| hdmi->field_ddc_int_status = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_int_status); |
| if (IS_ERR(hdmi->field_ddc_int_status)) |
| return PTR_ERR(hdmi->field_ddc_int_status); |
| |
| hdmi->field_ddc_fifo_clear = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_fifo_clear); |
| if (IS_ERR(hdmi->field_ddc_fifo_clear)) |
| return PTR_ERR(hdmi->field_ddc_fifo_clear); |
| |
| hdmi->field_ddc_fifo_rx_thres = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_fifo_rx_thres); |
| if (IS_ERR(hdmi->field_ddc_fifo_rx_thres)) |
| return PTR_ERR(hdmi->field_ddc_fifo_rx_thres); |
| |
| hdmi->field_ddc_fifo_tx_thres = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_fifo_tx_thres); |
| if (IS_ERR(hdmi->field_ddc_fifo_tx_thres)) |
| return PTR_ERR(hdmi->field_ddc_fifo_tx_thres); |
| |
| hdmi->field_ddc_byte_count = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_byte_count); |
| if (IS_ERR(hdmi->field_ddc_byte_count)) |
| return PTR_ERR(hdmi->field_ddc_byte_count); |
| |
| hdmi->field_ddc_cmd = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_cmd); |
| if (IS_ERR(hdmi->field_ddc_cmd)) |
| return PTR_ERR(hdmi->field_ddc_cmd); |
| |
| hdmi->field_ddc_sda_en = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_sda_en); |
| if (IS_ERR(hdmi->field_ddc_sda_en)) |
| return PTR_ERR(hdmi->field_ddc_sda_en); |
| |
| hdmi->field_ddc_sck_en = |
| devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, |
| hdmi->variant->field_ddc_sck_en); |
| if (IS_ERR(hdmi->field_ddc_sck_en)) |
| return PTR_ERR(hdmi->field_ddc_sck_en); |
| |
| return 0; |
| } |
| |
| int sun4i_hdmi_i2c_create(struct device *dev, struct sun4i_hdmi *hdmi) |
| { |
| struct i2c_adapter *adap; |
| int ret = 0; |
| |
| ret = sun4i_ddc_create(hdmi, hdmi->ddc_parent_clk); |
| if (ret) |
| return ret; |
| |
| ret = sun4i_hdmi_init_regmap_fields(hdmi); |
| if (ret) |
| return ret; |
| |
| adap = devm_kzalloc(dev, sizeof(*adap), GFP_KERNEL); |
| if (!adap) |
| return -ENOMEM; |
| |
| adap->owner = THIS_MODULE; |
| adap->class = I2C_CLASS_DDC; |
| adap->algo = &sun4i_hdmi_i2c_algorithm; |
| strlcpy(adap->name, "sun4i_hdmi_i2c adapter", sizeof(adap->name)); |
| i2c_set_adapdata(adap, hdmi); |
| |
| ret = i2c_add_adapter(adap); |
| if (ret) |
| return ret; |
| |
| hdmi->i2c = adap; |
| |
| return ret; |
| } |