> Subject: Re: [PATCH v13 2/3] i2c: aspeed: support AST2600 i2c new register > mode driver > > On Mon, Aug 19, 2024 at 05:28:49PM +0800, Ryan Chen wrote: > > Add i2c new register mode driver to support AST2600 i2c new register > > mode. AST2600 i2c controller have legacy and new register mode. The > > new register mode have global register support 4 base clock for scl > > clock selection, and new clock divider mode. The new register mode > > have separate register set to control i2c master and slave. This patch > > is for i2c master mode driver. > > ... > > > +struct ast2600_i2c_bus { > > Have you run `pahole` to be sure the layout is optimal? It will replace by following. struct ast2600_i2c_bus { struct i2c_adapter adap; struct device *dev; void __iomem *reg_base; struct regmap *global_regs; struct reset_control *rst; struct clk *clk; struct i2c_timings timing_info; struct completion cmd_complete; struct i2c_client *ara; struct i2c_msg *msgs; u8 *master_safe_buf; dma_addr_t master_dma_addr; u32 apb_clk; u32 timeout; int irq; int cmd_err; int msgs_index; int msgs_count; int master_xfer_cnt; size_t buf_index; size_t buf_size; enum xfer_mode mode; bool alert_enable; bool multi_master; /* Buffer mode */ void __iomem *buf_base; struct i2c_smbus_alert_setup alert_data; }; > > > + struct i2c_adapter adap; > > + struct device *dev; > > + void __iomem *reg_base; > > + struct regmap *global_regs; > > + struct reset_control *rst; > > + int irq; > > + enum xfer_mode mode; > > + struct clk *clk; > > + u32 apb_clk; > > + struct i2c_timings timing_info; > > + u32 timeout; > > + /* smbus alert */ > > + bool alert_enable; > > + struct i2c_smbus_alert_setup alert_data; > > + struct i2c_client *ara; > > + /* Multi-master */ > > + bool multi_master; > > + /* master structure */ > > + int cmd_err; > > + struct completion cmd_complete; > > + struct i2c_msg *msgs; > > + size_t buf_index; > > + /* cur xfer msgs index*/ > > + int msgs_index; > > + int msgs_count; > > + u8 *master_safe_buf; > > + dma_addr_t master_dma_addr; > > + /*total xfer count */ > > + int master_xfer_cnt; > > + /* Buffer mode */ > > + void __iomem *buf_base; > > + size_t buf_size; > > +}; > > ... > > > +static u32 ast2600_select_i2c_clock(struct ast2600_i2c_bus *i2c_bus) > > +{ > > + unsigned long base_clk[16]; > > + int baseclk_idx; > > + u32 clk_div_reg; > > + u32 scl_low; > > + u32 scl_high; > > + int divisor; > > + u32 data; > > + > > + regmap_read(i2c_bus->global_regs, AST2600_I2CG_CLK_DIV_CTRL, > > +&clk_div_reg); > > + > > + for (int i = 0; i < 16; i++) { > > unsigned int > ARRAY_SIZE(base_clk) // Will need array_size.h Will update to for (int i = 0; i < ARRAY_SIZE(base_clk); i++) And add include array_size.h > > > > + if (i == 0) > > + base_clk[i] = i2c_bus->apb_clk; > > + else if ((i > 0) || (i < 5)) > > + base_clk[i] = (i2c_bus->apb_clk * 2) / > > + (((clk_div_reg >> ((i - 1) * 8)) & GENMASK(7, 0)) + 2); > > + else > > + base_clk[i] = base_clk[4] / (1 << (i - 5)); > > This is the same as > > if (i == 0) > base_clk[i] = i2c_bus->apb_clk; > else if (i < 5) > base_clk[i] = (i2c_bus->apb_clk * 2) / > (((clk_div_reg / BIT((i - 1) * 8)) & GENMASK(7, 0)) + > 2); > else > base_clk[i] = base_clk[4] / BIT(i - 5); > > Alternatively > > if (i == 0) > base_clk[i] = i2c_bus->apb_clk; > else if (i < 5) > base_clk[i] = (i2c_bus->apb_clk * 2) / > (((clk_div_reg >> ((i - 1) * 8)) & GENMASK(7, 0)) + 2); > else > base_clk[i] = base_clk[4] >> (i - 5); > Will take the for better understand. if (i == 0) base_clk[i] = i2c_bus->apb_clk; else if (i < 5) base_clk[i] = (i2c_bus->apb_clk * 2) / (((clk_div_reg >> ((i - 1) * 8)) & GENMASK(7, 0)) + 2); else base_clk[i] = base_clk[4] >> (i - 5); > > + > > + if ((base_clk[i] / i2c_bus->timing_info.bus_freq_hz) <= 32) { > > + baseclk_idx = i; > > + divisor = DIV_ROUND_UP(base_clk[i], > i2c_bus->timing_info.bus_freq_hz); > > + break; > > + } > > + } > > > + baseclk_idx = min(baseclk_idx, 15); > > If the last conditional inside the loop is never true, you are going to use\ a > garbage here. I will give initial int baseclk_idx = 0; in function begin. > > > + divisor = min(divisor, 32); > > Ditto. I will give u32 divisor = 32; in function begin. > > > + scl_low = min(divisor * 9 / 16 - 1, 15); > > Missing minmax.h in the inclusion block. Will add. > > > + scl_high = (divisor - scl_low - 2) & GENMASK(3, 0); > > + data = (scl_high - 1) << 20 | scl_high << 16 | scl_low << 12 | baseclk_idx; > > + if (i2c_bus->timeout) { > > + data |= AST2600_I2CC_TOUTBASECLK(AST_I2C_TIMEOUT_CLK); > > + data |= AST2600_I2CC_TTIMEOUT(i2c_bus->timeout); > > + } > > + > > + return data; > > +} > > ... > > > +static u8 ast2600_i2c_recover_bus(struct ast2600_i2c_bus *i2c_bus) { > > + u32 state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF); > > + int ret = 0; > > + u32 ctrl; > > + int r; > > + > > + dev_dbg(i2c_bus->dev, "%d-bus recovery bus [%x]\n", > > +i2c_bus->adap.nr, state); > > + > > + ctrl = readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL); > > + > > + /* Disable master/slave mode */ > > + writel(ctrl & ~(AST2600_I2CC_MASTER_EN | AST2600_I2CC_SLAVE_EN), > > + i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL); > > + > > + /* Enable master mode only */ > > + writel(readl(i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL) | > AST2600_I2CC_MASTER_EN, > > + i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL); > > + > > + reinit_completion(&i2c_bus->cmd_complete); > > + i2c_bus->cmd_err = 0; > > + > > + /* Check 0x14's SDA and SCL status */ > > + state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF); > > + if (!(state & AST2600_I2CC_SDA_LINE_STS) && (state & > AST2600_I2CC_SCL_LINE_STS)) { > > + writel(AST2600_I2CM_RECOVER_CMD_EN, i2c_bus->reg_base + > AST2600_I2CM_CMD_STS); > > + r = wait_for_completion_timeout(&i2c_bus->cmd_complete, > i2c_bus->adap.timeout); > > + if (r == 0) { > > + dev_dbg(i2c_bus->dev, "recovery timed out\n"); > > + ret = -ETIMEDOUT; > > + } else { > > + if (i2c_bus->cmd_err) { > > + dev_dbg(i2c_bus->dev, "recovery error\n"); > > + ret = -EPROTO; > > + } > > + } > > + } > > ret is set but maybe overridden. > If will modify by following. if (r == 0) { dev_dbg(i2c_bus->dev, "recovery timed out\n"); ret = -ETIMEDOUT; } else if (i2c_bus->cmd_err) { dev_dbg(i2c_bus->dev, "recovery error\n"); ret = -EPROTO; } If no error keep ret = 0; > > + /* Recovery done */ > > Even if it fails above? This will keep check the bus status, if bus busy, will give ret = -EPROTO; > > > + state = readl(i2c_bus->reg_base + AST2600_I2CC_STS_AND_BUFF); > > + if (state & AST2600_I2CC_BUS_BUSY_STS) { > > + dev_dbg(i2c_bus->dev, "Can't recover bus [%x]\n", state); > > + ret = -EPROTO; > > + } > > + > > + /* restore original master/slave setting */ > > + writel(ctrl, i2c_bus->reg_base + AST2600_I2CC_FUN_CTRL); > > + return ret; > > +} > > ... > > > +static int ast2600_i2c_setup_dma_tx(u32 cmd, struct ast2600_i2c_bus > > +*i2c_bus) { > > + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index]; > > + int xfer_len; > > + > > + cmd |= AST2600_I2CM_PKT_EN; > > + xfer_len = msg->len - i2c_bus->master_xfer_cnt; > > + if (xfer_len > AST2600_I2C_DMA_SIZE) { > > + xfer_len = AST2600_I2C_DMA_SIZE; > > > + } else { > > + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) > > else if (...) Will update to else if(...). > > > + cmd |= AST2600_I2CM_STOP_CMD; > > + } > > + > > + if (cmd & AST2600_I2CM_START_CMD) { > > + cmd |= AST2600_I2CM_PKT_ADDR(msg->addr); > > + i2c_bus->master_safe_buf = i2c_get_dma_safe_msg_buf(msg, 1); > > + if (!i2c_bus->master_safe_buf) > > + return -ENOMEM; > > + i2c_bus->master_dma_addr = > > + dma_map_single(i2c_bus->dev, i2c_bus->master_safe_buf, > > + msg->len, DMA_TO_DEVICE); > > > + if (dma_mapping_error(i2c_bus->dev, i2c_bus->master_dma_addr)) > { > > + i2c_put_dma_safe_msg_buf(i2c_bus->master_safe_buf, msg, > false); > > + i2c_bus->master_safe_buf = NULL; > > > + return -ENOMEM; > > Why is the dma_mapping_error() returned error code shadowed? Sorry, please point me why you are think it is shadowed? As I know dma_mapping_error() will return 0 or -ENOMEM. So I check if it is !=0. Than return -ENOMEM. > > > + } > > + } > > + > > + if (xfer_len) { > > + cmd |= AST2600_I2CM_TX_DMA_EN | AST2600_I2CM_TX_CMD; > > + writel(AST2600_I2CM_SET_TX_DMA_LEN(xfer_len - 1), > > + i2c_bus->reg_base + AST2600_I2CM_DMA_LEN); > > + writel(i2c_bus->master_dma_addr + i2c_bus->master_xfer_cnt, > > + i2c_bus->reg_base + AST2600_I2CM_TX_DMA); > > + } > > + > > + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS); > > + > > + return 0; > > +} > > + > > +static int ast2600_i2c_setup_buff_tx(u32 cmd, struct ast2600_i2c_bus > > +*i2c_bus) { > > + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index]; > > + u32 wbuf_dword; > > + int xfer_len; > > + u8 wbuf[4]; > > > + int i; > > Why signed? Because it is for xfer len plus, also align with xfer_len and master_xfer_cnt in struct i2c_bus struct. > > > + cmd |= AST2600_I2CM_PKT_EN; > > + xfer_len = msg->len - i2c_bus->master_xfer_cnt; > > + if (xfer_len > i2c_bus->buf_size) { > > + xfer_len = i2c_bus->buf_size; > > > + } else { > > + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) > > else if (...) Will update else if (...). > > > + cmd |= AST2600_I2CM_STOP_CMD; > > + } > > + > > + if (cmd & AST2600_I2CM_START_CMD) > > + cmd |= AST2600_I2CM_PKT_ADDR(msg->addr); > > + > > + if (xfer_len) { > > + cmd |= AST2600_I2CM_TX_BUFF_EN | AST2600_I2CM_TX_CMD; > > > + /* > > + * The controller's buffer register supports dword writes only. > > + * Therefore, write dwords to the buffer register in a 4-byte aligned, > > + * and write the remaining unaligned data at the end. > > + */ > > + for (i = 0; i < xfer_len; i++) { > > + wbuf[i % 4] = msg->buf[i2c_bus->master_xfer_cnt + i]; > > + if ((i % 4) == 3 || i == xfer_len - 1) { > > + wbuf_dword = get_unaligned_le32(wbuf); > > + writel(wbuf_dword, i2c_bus->buf_base + i - (i % 4)); > > + } > > + } > > This is overcomplicated and can be simplified. > Why you can't perform > > get_unaligned_leXX(msg->buf[i2c_bus->master_xfer_cnt + i]); > > ? > > for (i = 0; i < xfer_len; i += 4) { > switch (min(xfer_len - i, 4) % 4) { > case 1: > wbuf_dword = ...; > writel(wbuf_dword, i2c_bus->buf_base + i); > break; > case 2: > wbuf_dword = get_unaligned_le16(...); > writel(wbuf_dword, i2c_bus->buf_base + i); > break; > case 3: > wbuf_dword = get_unaligned_le24(...); > writel(wbuf_dword, i2c_bus->buf_base + i); > break; > default: > wbuf_dword = get_unaligned_le32(...); > writel(wbuf_dword, i2c_bus->buf_base + i); > break; > } > } > > > Now, with this it's can be a helper, with which > > for (i = 0; i < xfer_len; i += 4) { > switch (min(xfer_len - i, 4) % 4) { > case 1: > ast2600_write_data(i2c_bus, i, ...); > break; > case 2: > ast2600_write_data(i2c_bus, i, get_unaligned_le16(...)); > break; > case 3: > ast2600_write_data(i2c_bus, i, get_unaligned_le24(...)); > break; > default: > ast2600_write_data(i2c_bus, i, get_unaligned_le32(...)); > break; > } > } > OK, I will modify by this. for (i = 0; i < xfer_len; i += 4) { switch (min(xfer_len - i, 4) % 4) { case 1: ast2600_write_data(i2c_bus, i, ...); break; case 2: ast2600_write_data(i2c_bus, i, get_unaligned_le16(...)); break; case 3: ast2600_write_data(i2c_bus, i, get_unaligned_le24(...)); break; default: ast2600_write_data(i2c_bus, i, get_unaligned_le32(...)); break; } } > > + writel(AST2600_I2CC_SET_TX_BUF_LEN(xfer_len), > > + i2c_bus->reg_base + AST2600_I2CC_BUFF_CTRL); > > + } > > + > > + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS); > > + > > + return 0; > > +} > > ... > > > +static int ast2600_i2c_setup_dma_rx(struct ast2600_i2c_bus *i2c_bus) > > +{ > > + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index]; > > + int xfer_len; > > + u32 cmd; > > + > > + cmd = AST2600_I2CM_PKT_EN | AST2600_I2CM_PKT_ADDR(msg->addr) > | > > + AST2600_I2CM_START_CMD | AST2600_I2CM_RX_DMA_EN; > > + > > + if (msg->flags & I2C_M_RECV_LEN) { > > + xfer_len = 1; > > > + } else { > > + if (msg->len > AST2600_I2C_DMA_SIZE) { > > } else if (...) { > Will update to else if (...) { > > + xfer_len = AST2600_I2C_DMA_SIZE; > > + } else { > > + xfer_len = msg->len; > > + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) > > + cmd |= MASTER_TRIGGER_LAST_STOP; > > + } > > + } > > + writel(AST2600_I2CM_SET_RX_DMA_LEN(xfer_len - 1), > i2c_bus->reg_base + AST2600_I2CM_DMA_LEN); > > + i2c_bus->master_safe_buf = i2c_get_dma_safe_msg_buf(msg, 1); > > + if (!i2c_bus->master_safe_buf) > > + return -ENOMEM; > > + i2c_bus->master_dma_addr = > > + dma_map_single(i2c_bus->dev, i2c_bus->master_safe_buf, msg->len, > DMA_FROM_DEVICE); > > + if (dma_mapping_error(i2c_bus->dev, i2c_bus->master_dma_addr)) { > > + i2c_put_dma_safe_msg_buf(i2c_bus->master_safe_buf, msg, false); > > + i2c_bus->master_safe_buf = NULL; > > + return -ENOMEM; > > + } > > + writel(i2c_bus->master_dma_addr, i2c_bus->reg_base + > > +AST2600_I2CM_RX_DMA); > > + > > + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS); > > + > > + return 0; > > +} > > + > > +static int ast2600_i2c_setup_buff_rx(struct ast2600_i2c_bus *i2c_bus) > > +{ > > + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index]; > > + int xfer_len; > > + u32 cmd; > > + > > + cmd = AST2600_I2CM_PKT_EN | AST2600_I2CM_PKT_ADDR(msg->addr) > | > > + AST2600_I2CM_START_CMD | AST2600_I2CM_RX_BUFF_EN; > > + > > + if (msg->flags & I2C_M_RECV_LEN) { > > + dev_dbg(i2c_bus->dev, "smbus read\n"); > > + xfer_len = 1; > > > + } else { > > + if (msg->len > i2c_bus->buf_size) { > > } else if (...) { Will update to else if (...) { > > > + xfer_len = i2c_bus->buf_size; > > + } else { > > + xfer_len = msg->len; > > + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) > > + cmd |= MASTER_TRIGGER_LAST_STOP; > > + } > > + } > > + writel(AST2600_I2CC_SET_RX_BUF_LEN(xfer_len), i2c_bus->reg_base + > > +AST2600_I2CC_BUFF_CTRL); > > + > > + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS); > > + > > + return 0; > > +} > > + > > +static int ast2600_i2c_setup_byte_rx(struct ast2600_i2c_bus *i2c_bus) > > +{ > > + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index]; > > + u32 cmd; > > + > > + cmd = AST2600_I2CM_PKT_EN | AST2600_I2CM_PKT_ADDR(msg->addr) > | > > + AST2600_I2CM_START_CMD | AST2600_I2CM_RX_CMD; > > + > > + if (msg->flags & I2C_M_RECV_LEN) { > > + dev_dbg(i2c_bus->dev, "smbus read\n"); > > > + } else { > > + if (i2c_bus->msgs_index + 1 == i2c_bus->msgs_count) { > > } else if (...) { > Will update to else if (...) { > > + if (msg->len == 1) > > + cmd |= MASTER_TRIGGER_LAST_STOP; > > + } > > + } > > + > > + writel(cmd, i2c_bus->reg_base + AST2600_I2CM_CMD_STS); > > + > > + return 0; > > +} > > ... > > > +static int ast2600_i2c_do_start(struct ast2600_i2c_bus *i2c_bus) { > > + struct i2c_msg *msg = &i2c_bus->msgs[i2c_bus->msgs_index]; > > + > > + /* send start */ > > + dev_dbg(i2c_bus->dev, "[%d] %sing %d byte%s %s 0x%02x\n", > > Drop 'ing', no need to have this in the debug message. Will Drop 'ing' > > > + i2c_bus->msgs_index, str_read_write(msg->flags & I2C_M_RD), > > + msg->len, msg->len > 1 ? "s" : "", > > str_plural() Will replace by following. dev_dbg(i2c_bus->dev, "[%d] %s %d byte%s %s 0x%02x\n", i2c_bus->msgs_index, str_read_write(msg->flags & I2C_M_RD), msg->len, str_plural(msg->len), > > > + msg->flags & I2C_M_RD ? "from" : "to", msg->addr); > > > + i2c_bus->master_xfer_cnt = 0; > > + i2c_bus->buf_index = 0; > > + > > + if (msg->flags & I2C_M_RD) { > > + if (i2c_bus->mode == DMA_MODE) > > + return ast2600_i2c_setup_dma_rx(i2c_bus); > > + else if (i2c_bus->mode == BUFF_MODE) > > + return ast2600_i2c_setup_buff_rx(i2c_bus); > > + else > > + return ast2600_i2c_setup_byte_rx(i2c_bus); > > + } else { > > + if (i2c_bus->mode == DMA_MODE) > > + return > ast2600_i2c_setup_dma_tx(AST2600_I2CM_START_CMD, i2c_bus); > > + else if (i2c_bus->mode == BUFF_MODE) > > + return ast2600_i2c_setup_buff_tx(AST2600_I2CM_START_CMD, > i2c_bus); > > + else > > + return > ast2600_i2c_setup_byte_tx(AST2600_I2CM_START_CMD, i2c_bus); > > + } > > +} > > ... > > > +master_out: > > + if (i2c_bus->mode == DMA_MODE) { > > + kfree(i2c_bus->master_safe_buf); > > + i2c_bus->master_safe_buf = NULL; > > + } > > Indentation issues. Will update > > > + return ret; > > ... > > > > +MODULE_DEVICE_TABLE(of, ast2600_i2c_bus_of_table); > > Why do you need this table before _probe()? Isn't the only user is below? It is for next generation table list. Do you suggest remove it? > > > +static int ast2600_i2c_probe(struct platform_device *pdev) > > ... > > > + i2c_bus->global_regs = > syscon_regmap_lookup_by_phandle(dev->of_node, > > +"aspeed,global-regs"); > > dev_of_node(dev) Will update i2c_bus->global_regs = syscon_regmap_lookup_by_phandle(dev_of_node(dev), "aspeed,global-regs"); > > > + if (IS_ERR(i2c_bus->global_regs)) > > + return PTR_ERR(i2c_bus->global_regs); > > ... > > > + if (device_property_read_bool(&pdev->dev, "aspeed,enable-dma")) > > You have 'dev' Why not use it? Will update if (device_property_read_bool(dev, "aspeed,enable-dma")) > > > + i2c_bus->mode = DMA_MODE; > > ... > > > + if (i2c_bus->mode == BUFF_MODE) { > > + i2c_bus->buf_base = > devm_platform_get_and_ioremap_resource(pdev, 1, &res); > > + if (!IS_ERR_OR_NULL(i2c_bus->buf_base)) > > + i2c_bus->buf_size = resource_size(res) / 2; > > + else > > + i2c_bus->mode = BYTE_MODE; > > What's wrong with positive conditional? And is it even possible to have NULL > here? > Yes, if dtsi fill not following yaml example have reg 1, that will failure at buffer mode. And I can swith to byte mode. reg = <0x80 0x80>, <0xc00 0x20>; > > + } > > ... > > > + strscpy(i2c_bus->adap.name, pdev->name, sizeof(i2c_bus->adap.name)); > > Use 2-argument strscpy(). Do you mean strscpy(i2c_bus->adap.name, pdev->name); is acceptable? > > ... > > > + i2c_bus->alert_enable = device_property_read_bool(dev, "smbus-alert"); > > + if (i2c_bus->alert_enable) { > > + i2c_bus->ara = i2c_new_smbus_alert_device(&i2c_bus->adap, > &i2c_bus->alert_data); > > + if (!i2c_bus->ara) > > + dev_warn(dev, "Failed to register ARA client\n"); > > + > > + writel(AST2600_I2CM_PKT_DONE | AST2600_I2CM_BUS_RECOVER > | AST2600_I2CM_SMBUS_ALT, > > + i2c_bus->reg_base + AST2600_I2CM_IER); > > + } else { > > + i2c_bus->alert_enable = false; > > + /* Set interrupt generation of I2C master controller */ > > + writel(AST2600_I2CM_PKT_DONE | AST2600_I2CM_BUS_RECOVER, > > + i2c_bus->reg_base + AST2600_I2CM_IER); > > + } > > I2C core calls i2c_setup_smbus_alert() when registering the adapter. Why do > you need to have something special here? The ast2600 i2c support smbus alert, and according my reference. If enable alert, that will need i2c_new_smbus_alert_device for alert handler. When interrupt coming driver can use this hander to up use i2c_handle_smbus_alert And update layer will handle alert. Does I mis-understand. If yes, I will remove this in next. > > -- > With Best Regards, > Andy Shevchenko >