From b41a216dafe4dd23c95cb4203de288f773a097a6 Mon Sep 17 00:00:00 2001 From: Roland Stigge Date: Sun, 22 Apr 2012 11:59:47 +0200 Subject: [PATCH] i2c: Add device tree support to i2c-pnx.c This patch adds device tree support to the pnx-i2c driver by using platform resources for memory region and irq and removing dependency on mach includes. The following platforms are affected: * PNX * LPC31xx (WIP) * LPC32xx The patch is based on a patch by Jon Smirl, working on lpc31xx integration Signed-off-by: Roland Stigge Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/pnx.txt | 36 +++++++++++ drivers/i2c/busses/i2c-pnx.c | 63 ++++++++++++++----- include/linux/i2c-pnx.h | 1 + 3 files changed, 84 insertions(+), 16 deletions(-) create mode 100644 Documentation/devicetree/bindings/i2c/pnx.txt diff --git a/Documentation/devicetree/bindings/i2c/pnx.txt b/Documentation/devicetree/bindings/i2c/pnx.txt new file mode 100644 index 000000000000..fe98ada33ee4 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/pnx.txt @@ -0,0 +1,36 @@ +* NXP PNX I2C Controller + +Required properties: + + - reg: Offset and length of the register set for the device + - compatible: should be "nxp,pnx-i2c" + - interrupts: configure one interrupt line + - #address-cells: always 1 (for i2c addresses) + - #size-cells: always 0 + - interrupt-parent: the phandle for the interrupt controller that + services interrupts for this device. + +Optional properties: + + - clock-frequency: desired I2C bus clock frequency in Hz, Default: 100000 Hz + +Examples: + + i2c1: i2c@400a0000 { + compatible = "nxp,pnx-i2c"; + reg = <0x400a0000 0x100>; + interrupt-parent = <&mic>; + interrupts = <51 0>; + #address-cells = <1>; + #size-cells = <0>; + }; + + i2c2: i2c@400a8000 { + compatible = "nxp,pnx-i2c"; + reg = <0x400a8000 0x100>; + interrupt-parent = <&mic>; + interrupts = <50 0>; + #address-cells = <1>; + #size-cells = <0>; + clock-frequency = <100000>; + }; diff --git a/drivers/i2c/busses/i2c-pnx.c b/drivers/i2c/busses/i2c-pnx.c index f69d80b8d736..99389d2eae51 100644 --- a/drivers/i2c/busses/i2c-pnx.c +++ b/drivers/i2c/busses/i2c-pnx.c @@ -23,10 +23,11 @@ #include #include #include +#include -#define I2C_PNX_TIMEOUT 10 /* msec */ -#define I2C_PNX_SPEED_KHZ 100 -#define I2C_PNX_REGION_SIZE 0x100 +#define I2C_PNX_TIMEOUT_DEFAULT 10 /* msec */ +#define I2C_PNX_SPEED_KHZ_DEFAULT 100 +#define I2C_PNX_REGION_SIZE 0x100 enum { mstatus_tdi = 0x00000001, @@ -74,8 +75,9 @@ enum { #define I2C_REG_TXS(a) ((a)->ioaddr + 0x28) /* Tx slave FIFO (RO) */ #define I2C_REG_STFL(a) ((a)->ioaddr + 0x2c) /* Tx slave FIFO level (RO) */ -static inline int wait_timeout(long timeout, struct i2c_pnx_algo_data *data) +static inline int wait_timeout(struct i2c_pnx_algo_data *data) { + long timeout = data->timeout; while (timeout > 0 && (ioread32(I2C_REG_STS(data)) & mstatus_active)) { mdelay(1); @@ -84,8 +86,9 @@ static inline int wait_timeout(long timeout, struct i2c_pnx_algo_data *data) return (timeout <= 0); } -static inline int wait_reset(long timeout, struct i2c_pnx_algo_data *data) +static inline int wait_reset(struct i2c_pnx_algo_data *data) { + long timeout = data->timeout; while (timeout > 0 && (ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) { mdelay(1); @@ -97,7 +100,7 @@ static inline int wait_reset(long timeout, struct i2c_pnx_algo_data *data) static inline void i2c_pnx_arm_timer(struct i2c_pnx_algo_data *alg_data) { struct timer_list *timer = &alg_data->mif.timer; - unsigned long expires = msecs_to_jiffies(I2C_PNX_TIMEOUT); + unsigned long expires = msecs_to_jiffies(alg_data->timeout); if (expires <= 1) expires = 2; @@ -135,7 +138,7 @@ static int i2c_pnx_start(unsigned char slave_addr, } /* First, make sure bus is idle */ - if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) { + if (wait_timeout(alg_data)) { /* Somebody else is monopolizing the bus */ dev_err(&alg_data->adapter.dev, "%s: Bus busy. Slave addr = %02x, cntrl = %x, stat = %x\n", @@ -228,7 +231,7 @@ static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data) if (alg_data->mif.len == 0) { if (alg_data->last) { /* Wait until the STOP is seen. */ - if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) + if (wait_timeout(alg_data)) dev_err(&alg_data->adapter.dev, "The bus is still active after timeout\n"); } @@ -326,7 +329,7 @@ static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data) if (alg_data->mif.len == 0) { if (alg_data->last) /* Wait until the STOP is seen. */ - if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) + if (wait_timeout(alg_data)) dev_err(&alg_data->adapter.dev, "The bus is still active after timeout\n"); @@ -442,7 +445,7 @@ static void i2c_pnx_timeout(unsigned long data) ctl |= mcntrl_reset; iowrite32(ctl, I2C_REG_CTL(alg_data)); - wait_reset(I2C_PNX_TIMEOUT, alg_data); + wait_reset(alg_data); alg_data->mif.ret = -EIO; complete(&alg_data->mif.complete); } @@ -457,18 +460,18 @@ static inline void bus_reset_if_active(struct i2c_pnx_algo_data *alg_data) alg_data->adapter.name); iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset, I2C_REG_CTL(alg_data)); - wait_reset(I2C_PNX_TIMEOUT, alg_data); + wait_reset(alg_data); } else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) { /* If there is data in the fifo's after transfer, * flush fifo's by reset. */ iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset, I2C_REG_CTL(alg_data)); - wait_reset(I2C_PNX_TIMEOUT, alg_data); + wait_reset(alg_data); } else if (stat & mstatus_nai) { iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset, I2C_REG_CTL(alg_data)); - wait_reset(I2C_PNX_TIMEOUT, alg_data); + wait_reset(alg_data); } } @@ -612,6 +615,7 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) struct i2c_pnx_algo_data *alg_data; unsigned long freq; struct resource *res; + u32 speed = I2C_PNX_SPEED_KHZ_DEFAULT * 1000; alg_data = kzalloc(sizeof(*alg_data), GFP_KERNEL); if (!alg_data) { @@ -626,6 +630,22 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) alg_data->adapter.algo_data = alg_data; alg_data->adapter.nr = pdev->id; + alg_data->timeout = I2C_PNX_TIMEOUT_DEFAULT; +#ifdef CONFIG_OF + alg_data->adapter.dev.of_node = of_node_get(pdev->dev.of_node); + if (pdev->dev.of_node) { + of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &speed); + /* + * At this point, it is planned to add an OF timeout property. + * As soon as there is a consensus about how to call and handle + * this, sth. like the following can be put here: + * + * of_property_read_u32(pdev->dev.of_node, "timeout", + * &alg_data->timeout); + */ + } +#endif alg_data->clk = clk_get(&pdev->dev, NULL); if (IS_ERR(alg_data->clk)) { ret = PTR_ERR(alg_data->clk); @@ -651,7 +671,7 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) dev_err(&pdev->dev, "I/O region 0x%08x for I2C already in use.\n", res->start); - ret = -ENODEV; + ret = -ENOMEM; goto out_clkget; } @@ -680,14 +700,14 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) * the deglitching filter length. */ - tmp = ((freq / 1000) / I2C_PNX_SPEED_KHZ) / 2 - 2; + tmp = (freq / speed) / 2 - 2; if (tmp > 0x3FF) tmp = 0x3FF; iowrite32(tmp, I2C_REG_CKH(alg_data)); iowrite32(tmp, I2C_REG_CKL(alg_data)); iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data)); - if (wait_reset(I2C_PNX_TIMEOUT, alg_data)) { + if (wait_reset(alg_data)) { ret = -ENODEV; goto out_clock; } @@ -710,6 +730,8 @@ static int __devinit i2c_pnx_probe(struct platform_device *pdev) goto out_irq; } + of_i2c_register_devices(&alg_data->adapter); + dev_dbg(&pdev->dev, "%s: Master at %#8x, irq %d.\n", alg_data->adapter.name, res->start, alg_data->irq); @@ -748,10 +770,19 @@ static int __devexit i2c_pnx_remove(struct platform_device *pdev) return 0; } +#ifdef CONFIG_OF +static const struct of_device_id i2c_pnx_of_match[] = { + { .compatible = "nxp,pnx-i2c" }, + { }, +}; +MODULE_DEVICE_TABLE(of, i2c_pnx_of_match); +#endif + static struct platform_driver i2c_pnx_driver = { .driver = { .name = "pnx-i2c", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(i2c_pnx_of_match), }, .probe = i2c_pnx_probe, .remove = __devexit_p(i2c_pnx_remove), diff --git a/include/linux/i2c-pnx.h b/include/linux/i2c-pnx.h index 6e8efb7afd7c..1bc74afe7a35 100644 --- a/include/linux/i2c-pnx.h +++ b/include/linux/i2c-pnx.h @@ -32,6 +32,7 @@ struct i2c_pnx_algo_data { struct i2c_adapter adapter; phys_addr_t base; int irq; + u32 timeout; }; #endif /* __I2C_PNX_H__ */