From f2bd5efe723814916ece92ccfa0bffb085c94b94 Mon Sep 17 00:00:00 2001 From: Wolfgang Grandegger Date: Tue, 7 Apr 2009 10:20:55 +0200 Subject: [PATCH] i2c: i2c-mpc: make I2C bus speed configurable This patch makes the I2C bus speed configurable by using the I2C node property "clock-frequency". If the property is not defined, the old fixed clock settings will be used for backward comptibility. The generic I2C clock properties, especially the CPU-specific source clock pre-scaler are defined via the OF match table: static const struct of_device_id mpc_i2c_of_match[] = { ... {.compatible = "fsl,mpc8543-i2c", .data = &(struct fsl_i2c_match_data) { .setclock = mpc_i2c_setclock_8xxx, .prescaler = 2, }, }, The "data" field defines the relevant I2C setclock function and the relevant pre-scaler for the I2C source clock frequency. It uses arch-specific tables and functions to determine resonable Freqency Divider Register (fdr) values for MPC83xx, MPC85xx, MPC86xx, MPC5200 and MPC5200B. The i2c->flags field and the corresponding FSL_I2C_DEV_* definitions have been removed as they are obsolete. Signed-off-by: Wolfgang Grandegger Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-mpc.c | 262 ++++++++++++++++++++++++++++++++--- 1 file changed, 242 insertions(+), 20 deletions(-) diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index 9b38c9236464..4af5c09f0e8f 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -26,6 +26,9 @@ #include #include +#include +#include + #define DRV_NAME "mpc-i2c" #define MPC_I2C_FDR 0x04 @@ -56,7 +59,18 @@ struct mpc_i2c { wait_queue_head_t queue; struct i2c_adapter adap; int irq; - u32 flags; +}; + +struct mpc_i2c_divider { + u16 divider; + u16 fdr; /* including dfsrr */ +}; + +struct mpc_i2c_match_data { + void (*setclock)(struct device_node *node, + struct mpc_i2c *i2c, + u32 clock, u32 prescaler); + u32 prescaler; }; static inline void writeccr(struct mpc_i2c *i2c, u32 x) @@ -150,18 +164,181 @@ static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing) return 0; } -static void mpc_i2c_setclock(struct mpc_i2c *i2c) +#ifdef CONFIG_PPC_52xx +static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = { + {20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23}, + {28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02}, + {36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28}, + {52, 0x63}, {56, 0x29}, {60, 0x41}, {64, 0x2a}, + {68, 0x07}, {72, 0x2b}, {80, 0x2c}, {88, 0x09}, + {96, 0x2d}, {104, 0x0a}, {112, 0x2e}, {120, 0x81}, + {128, 0x2f}, {136, 0x47}, {144, 0x0c}, {160, 0x30}, + {176, 0x49}, {192, 0x31}, {208, 0x4a}, {224, 0x32}, + {240, 0x0f}, {256, 0x33}, {272, 0x87}, {288, 0x10}, + {320, 0x34}, {352, 0x89}, {384, 0x35}, {416, 0x8a}, + {448, 0x36}, {480, 0x13}, {512, 0x37}, {576, 0x14}, + {640, 0x38}, {768, 0x39}, {896, 0x3a}, {960, 0x17}, + {1024, 0x3b}, {1152, 0x18}, {1280, 0x3c}, {1536, 0x3d}, + {1792, 0x3e}, {1920, 0x1b}, {2048, 0x3f}, {2304, 0x1c}, + {2560, 0x1d}, {3072, 0x1e}, {3584, 0x7e}, {3840, 0x1f}, + {4096, 0x7f}, {4608, 0x5c}, {5120, 0x5d}, {6144, 0x5e}, + {7168, 0xbe}, {7680, 0x5f}, {8192, 0xbf}, {9216, 0x9c}, + {10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f} +}; + +int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, int prescaler) { - /* Set clock and filters */ - if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR) { - writeb(0x31, i2c->base + MPC_I2C_FDR); - writeb(0x10, i2c->base + MPC_I2C_DFSRR); - } else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200) - writeb(0x3f, i2c->base + MPC_I2C_FDR); - else - writel(0x1031, i2c->base + MPC_I2C_FDR); + const struct mpc52xx_i2c_divider *div = NULL; + unsigned int pvr = mfspr(SPRN_PVR); + u32 divider; + int i; + + if (!clock) + return -EINVAL; + + /* Determine divider value */ + divider = mpc52xx_find_ipb_freq(node) / clock; + + /* + * We want to choose an FDR/DFSR that generates an I2C bus speed that + * is equal to or lower than the requested speed. + */ + for (i = 0; i < ARRAY_SIZE(mpc52xx_i2c_dividers); i++) { + div = &mpc_i2c_dividers_52xx[i]; + /* Old MPC5200 rev A CPUs do not support the high bits */ + if (div->fdr & 0xc0 && pvr == 0x80822011) + continue; + if (div->divider >= divider) + break; + } + + return div ? (int)div->fdr : -EINVAL; } +static void mpc_i2c_setclock_52xx(struct device_node *node, + struct mpc_i2c *i2c, + u32 clock, u32 prescaler) +{ + int fdr = mpc52xx_i2c_get_fdr(node, clock, prescaler); + + if (fdr < 0) + fdr = 0x3f; /* backward compatibility */ + writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR); + dev_info(i2c->dev, "clock %d Hz (fdr=%d)\n", clock, fdr); +} +#else /* !CONFIG_PPC_52xx */ +static void mpc_i2c_setclock_52xx(struct device_node *node, + struct mpc_i2c *i2c, + u32 clock, u32 prescaler) +{ +} +#endif /* CONFIG_PPC_52xx*/ + +#ifdef CONFIG_FSL_SOC +static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = { + {160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123}, + {288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102}, + {416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127}, + {544, 0x0b03}, {576, 0x0104}, {608, 0x1603}, {640, 0x0105}, + {672, 0x2003}, {704, 0x0b05}, {736, 0x2b03}, {768, 0x0106}, + {800, 0x3603}, {832, 0x0b06}, {896, 0x012a}, {960, 0x0107}, + {1024, 0x012b}, {1088, 0x1607}, {1152, 0x0108}, {1216, 0x2b07}, + {1280, 0x0109}, {1408, 0x1609}, {1536, 0x010a}, {1664, 0x160a}, + {1792, 0x012e}, {1920, 0x010b}, {2048, 0x012f}, {2176, 0x2b0b}, + {2304, 0x010c}, {2560, 0x010d}, {2816, 0x2b0d}, {3072, 0x010e}, + {3328, 0x2b0e}, {3584, 0x0132}, {3840, 0x010f}, {4096, 0x0133}, + {4608, 0x0110}, {5120, 0x0111}, {6144, 0x0112}, {7168, 0x0136}, + {7680, 0x0113}, {8192, 0x0137}, {9216, 0x0114}, {10240, 0x0115}, + {12288, 0x0116}, {14336, 0x013a}, {15360, 0x0117}, {16384, 0x013b}, + {18432, 0x0118}, {20480, 0x0119}, {24576, 0x011a}, {28672, 0x013e}, + {30720, 0x011b}, {32768, 0x013f}, {36864, 0x011c}, {40960, 0x011d}, + {49152, 0x011e}, {61440, 0x011f} +}; + +u32 mpc_i2c_get_sec_cfg_8xxx(void) +{ + struct device_node *node = NULL; + u32 __iomem *reg; + u32 val = 0; + + node = of_find_node_by_name(NULL, "global-utilities"); + if (node) { + const u32 *prop = of_get_property(node, "reg", NULL); + if (prop) { + /* + * Map and check POR Device Status Register 2 + * (PORDEVSR2) at 0xE0014 + */ + reg = ioremap(get_immrbase() + *prop + 0x14, 0x4); + if (!reg) + printk(KERN_ERR + "Error: couldn't map PORDEVSR2\n"); + else + val = in_be32(reg) & 0x00000080; /* sec-cfg */ + iounmap(reg); + } + } + if (node) + of_node_put(node); + + return val; +} + +int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, u32 prescaler) +{ + const struct mpc_i2c_divider *div = NULL; + u32 divider; + int i; + + if (!clock) + return -EINVAL; + + /* Determine proper divider value */ + if (of_device_is_compatible(node, "fsl,mpc8544-i2c")) + prescaler = mpc_i2c_get_sec_cfg_8xxx() ? 3 : 2; + if (!prescaler) + prescaler = 1; + + divider = fsl_get_sys_freq() / clock / prescaler; + + pr_debug("I2C: src_clock=%d clock=%d divider=%d\n", + fsl_get_sys_freq(), clock, divider); + + /* + * We want to choose an FDR/DFSR that generates an I2C bus speed that + * is equal to or lower than the requested speed. + */ + for (i = 0; i < ARRAY_SIZE(mpc_i2c_dividers_8xxx); i++) { + div = &mpc_i2c_dividers_8xxx[i]; + if (div->divider >= divider) + break; + } + + return div ? (int)div->fdr : -EINVAL; +} + +static void mpc_i2c_setclock_8xxx(struct device_node *node, + struct mpc_i2c *i2c, + u32 clock, u32 prescaler) +{ + int fdr = mpc_i2c_get_fdr_8xxx(node, clock, prescaler); + + if (fdr < 0) + fdr = 0x1031; /* backward compatibility */ + writeb(fdr & 0xff, i2c->base + MPC_I2C_FDR); + writeb((fdr >> 8) & 0xff, i2c->base + MPC_I2C_DFSRR); + dev_info(i2c->dev, "clock %d Hz (dfsrr=%d fdr=%d)\n", + clock, fdr >> 8, fdr & 0xff); +} + +#else /* !CONFIG_FSL_SOC */ +static void mpc_i2c_setclock_8xxx(struct device_node *node, + struct mpc_i2c *i2c, + u32 clock, u32 prescaler) +{ +} +#endif /* CONFIG_FSL_SOC */ + static void mpc_i2c_start(struct mpc_i2c *i2c) { /* Clear arbitration */ @@ -315,8 +492,11 @@ static struct i2c_adapter mpc_ops = { static int __devinit fsl_i2c_probe(struct of_device *op, const struct of_device_id *match) { - int result = 0; struct mpc_i2c *i2c; + const u32 *prop; + u32 clock = 0; + int result = 0; + int plen; i2c = kzalloc(sizeof(*i2c), GFP_KERNEL); if (!i2c) @@ -324,13 +504,6 @@ static int __devinit fsl_i2c_probe(struct of_device *op, i2c->dev = &op->dev; /* for debug and error output */ - if (of_get_property(op->node, "dfsrr", NULL)) - i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; - - if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || - of_device_is_compatible(op->node, "mpc5200-i2c")) - i2c->flags |= FSL_I2C_DEV_CLOCK_5200; - init_waitqueue_head(&i2c->queue); i2c->base = of_iomap(op->node, 0); @@ -350,7 +523,22 @@ static int __devinit fsl_i2c_probe(struct of_device *op, } } - mpc_i2c_setclock(i2c); + if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) { + prop = of_get_property(op->node, "clock-frequency", &plen); + if (prop && plen == sizeof(u32)) + clock = *prop; + + if (match->data) { + struct mpc_i2c_match_data *data = + (struct mpc_i2c_match_data *)match->data; + data->setclock(op->node, i2c, clock, data->prescaler); + } else { + /* Backwards compatibility */ + if (of_get_property(op->node, "dfsrr", NULL)) + mpc_i2c_setclock_8xxx(op->node, i2c, + clock, 0); + } + } dev_set_drvdata(&op->dev, i2c); @@ -395,9 +583,43 @@ static int __devexit fsl_i2c_remove(struct of_device *op) }; static const struct of_device_id mpc_i2c_of_match[] = { - {.compatible = "fsl-i2c",}, + {.compatible = "mpc5200-i2c", + .data = &(struct mpc_i2c_match_data) { + .setclock = mpc_i2c_setclock_52xx, + }, + }, + {.compatible = "fsl,mpc5200b-i2c", + .data = &(struct mpc_i2c_match_data) { + .setclock = mpc_i2c_setclock_52xx, + }, + }, + {.compatible = "fsl,mpc5200-i2c", + .data = &(struct mpc_i2c_match_data) { + .setclock = mpc_i2c_setclock_52xx, + }, + }, + {.compatible = "fsl,mpc8313-i2c", + .data = &(struct mpc_i2c_match_data) { + .setclock = mpc_i2c_setclock_8xxx, + }, + }, + {.compatible = "fsl,mpc8543-i2c", + .data = &(struct mpc_i2c_match_data) { + .setclock = mpc_i2c_setclock_8xxx, + .prescaler = 2, + }, + }, + {.compatible = "fsl,mpc8544-i2c", + .data = &(struct mpc_i2c_match_data) { + .setclock = mpc_i2c_setclock_8xxx, + .prescaler = 3, + }, + /* Backward compatibility */ + }, + {.compatible = "fsl-i2c", }, {}, }; + MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);