diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0122-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.4/0122-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0122-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch b/target/linux/brcm2708/patches-4.4/0122-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch new file mode 100644 index 0000000000..8f578ab71e --- /dev/null +++ b/target/linux/brcm2708/patches-4.4/0122-Extend-clock-timeout-fix-modprobe-baudrate-parameter.patch @@ -0,0 +1,108 @@ +From ba2e42fe23631e6cf1f2e1167618ab1c13d9b3ba Mon Sep 17 00:00:00 2001 +From: Devon Fyson <devonfyson@gmail.com> +Date: Wed, 30 Dec 2015 16:40:47 -0500 +Subject: [PATCH 122/127] Extend clock timeout, fix modprobe baudrate + parameter. + +Set the BSC_CLKT clock streching timeout to 35ms as per SMBus specs.\n- Increase priority of baudrate parameter passed to modprobe (in /etc/modprobe.d/*.conf or command line). Currently custom baudrates don't work because they are overridden by clock-frequency in the platform_device passed to the function. +--- + drivers/i2c/busses/i2c-bcm2708.c | 45 ++++++++++++++++++++++++++-------------- + 1 file changed, 29 insertions(+), 16 deletions(-) + +--- a/drivers/i2c/busses/i2c-bcm2708.c ++++ b/drivers/i2c/busses/i2c-bcm2708.c +@@ -71,7 +71,8 @@ + + #define DRV_NAME "bcm2708_i2c" + +-static unsigned int baudrate = CONFIG_I2C_BCM2708_BAUDRATE; ++static unsigned int baudrate_default = CONFIG_I2C_BCM2708_BAUDRATE; ++static unsigned int baudrate; + module_param(baudrate, uint, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); + MODULE_PARM_DESC(baudrate, "The I2C baudrate"); + +@@ -87,6 +88,7 @@ struct bcm2708_i2c { + int irq; + struct clk *clk; + u32 cdiv; ++ u32 clk_tout; + + struct completion done; + +@@ -126,7 +128,7 @@ static inline void bcm2708_bsc_fifo_fill + + static inline int bcm2708_bsc_setup(struct bcm2708_i2c *bi) + { +- u32 cdiv, s; ++ u32 cdiv, s, clk_tout; + u32 c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_ST | BSC_C_CLEAR_1; + int wait_loops = I2C_WAIT_LOOP_COUNT; + +@@ -134,12 +136,14 @@ static inline int bcm2708_bsc_setup(stru + * Use the value that we cached in the probe. + */ + cdiv = bi->cdiv; ++ clk_tout = bi->clk_tout; + + if (bi->msg->flags & I2C_M_RD) + c |= BSC_C_INTR | BSC_C_READ; + else + c |= BSC_C_INTT; + ++ bcm2708_wr(bi, BSC_CLKT, clk_tout); + bcm2708_wr(bi, BSC_DIV, cdiv); + bcm2708_wr(bi, BSC_A, bi->msg->addr); + bcm2708_wr(bi, BSC_DLEN, bi->msg->len); +@@ -312,21 +316,24 @@ static int bcm2708_i2c_probe(struct plat + struct bcm2708_i2c *bi; + struct i2c_adapter *adap; + unsigned long bus_hz; +- u32 cdiv; +- +- if (pdev->dev.of_node) { +- u32 bus_clk_rate; +- pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c"); +- if (pdev->id < 0) { +- dev_err(&pdev->dev, "alias is missing\n"); +- return -EINVAL; ++ u32 cdiv, clk_tout; ++ ++ if (!baudrate) { ++ baudrate = baudrate_default; ++ if (pdev->dev.of_node) { ++ u32 bus_clk_rate; ++ pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c"); ++ if (pdev->id < 0) { ++ dev_err(&pdev->dev, "alias is missing\n"); ++ return -EINVAL; ++ } ++ if (!of_property_read_u32(pdev->dev.of_node, ++ "clock-frequency", &bus_clk_rate)) ++ baudrate = bus_clk_rate; ++ else ++ dev_warn(&pdev->dev, ++ "Could not read clock-frequency property\n"); + } +- if (!of_property_read_u32(pdev->dev.of_node, +- "clock-frequency", &bus_clk_rate)) +- baudrate = bus_clk_rate; +- else +- dev_warn(&pdev->dev, +- "Could not read clock-frequency property\n"); + } + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); +@@ -417,7 +424,13 @@ static int bcm2708_i2c_probe(struct plat + cdiv = 0xffff; + baudrate = bus_hz / cdiv; + } ++ ++ clk_tout = 35/1000*baudrate; //35ms timeout as per SMBus specs. ++ if (clk_tout > 0xffff) ++ clk_tout = 0xffff; ++ + bi->cdiv = cdiv; ++ bi->clk_tout = clk_tout; + + dev_info(&pdev->dev, "BSC%d Controller at 0x%08lx (irq %d) (baudrate %d)\n", + pdev->id, (unsigned long)regs->start, irq, baudrate); |