diff options
Diffstat (limited to 'drivers/ssbi/ssbi.c')
| -rw-r--r-- | drivers/ssbi/ssbi.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/drivers/ssbi/ssbi.c b/drivers/ssbi/ssbi.c new file mode 100644 index 000000000000..8b0b10d6e1de --- /dev/null +++ b/drivers/ssbi/ssbi.c @@ -0,0 +1,397 @@ +/* Copyright (c) 2009-2011, Code Aurora Forum. All rights reserved. + * Copyright (c) 2010, Google Inc. + * + * Original authors: Code Aurora Forum + * + * Author: Dima Zavin <dima@android.com> + * - Largely rewritten from original to not be an i2c driver. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/msm_ssbi.h> +#include <linux/module.h> + +/* SSBI 2.0 controller registers */ +#define SSBI2_CMD 0x0008 +#define SSBI2_RD 0x0010 +#define SSBI2_STATUS 0x0014 +#define SSBI2_MODE2 0x001C + +/* SSBI_CMD fields */ +#define SSBI_CMD_RDWRN (1 << 24) + +/* SSBI_STATUS fields */ +#define SSBI_STATUS_RD_READY (1 << 2) +#define SSBI_STATUS_READY (1 << 1) +#define SSBI_STATUS_MCHN_BUSY (1 << 0) + +/* SSBI_MODE2 fields */ +#define SSBI_MODE2_REG_ADDR_15_8_SHFT 0x04 +#define SSBI_MODE2_REG_ADDR_15_8_MASK (0x7f << SSBI_MODE2_REG_ADDR_15_8_SHFT) + +#define SET_SSBI_MODE2_REG_ADDR_15_8(MD, AD) \ + (((MD) & 0x0F) | ((((AD) >> 8) << SSBI_MODE2_REG_ADDR_15_8_SHFT) & \ + SSBI_MODE2_REG_ADDR_15_8_MASK)) + +/* SSBI PMIC Arbiter command registers */ +#define SSBI_PA_CMD 0x0000 +#define SSBI_PA_RD_STATUS 0x0004 + +/* SSBI_PA_CMD fields */ +#define SSBI_PA_CMD_RDWRN (1 << 24) +#define SSBI_PA_CMD_ADDR_MASK 0x7fff /* REG_ADDR_7_0, REG_ADDR_8_14*/ + +/* SSBI_PA_RD_STATUS fields */ +#define SSBI_PA_RD_STATUS_TRANS_DONE (1 << 27) +#define SSBI_PA_RD_STATUS_TRANS_DENIED (1 << 26) + +#define SSBI_TIMEOUT_US 100 + +struct msm_ssbi { + struct device *dev; + struct device *slave; + void __iomem *base; + spinlock_t lock; + enum msm_ssbi_controller_type controller_type; + int (*read)(struct msm_ssbi *, u16 addr, u8 *buf, int len); + int (*write)(struct msm_ssbi *, u16 addr, u8 *buf, int len); +}; + +#define to_msm_ssbi(dev) platform_get_drvdata(to_platform_device(dev)) + +static inline u32 ssbi_readl(struct msm_ssbi *ssbi, u32 reg) +{ + return readl(ssbi->base + reg); +} + +static inline void ssbi_writel(struct msm_ssbi *ssbi, u32 val, u32 reg) +{ + writel(val, ssbi->base + reg); +} + +static int ssbi_wait_mask(struct msm_ssbi *ssbi, u32 set_mask, u32 clr_mask) +{ + u32 timeout = SSBI_TIMEOUT_US; + u32 val; + + while (timeout--) { + val = ssbi_readl(ssbi, SSBI2_STATUS); + if (((val & set_mask) == set_mask) && ((val & clr_mask) == 0)) + return 0; + udelay(1); + } + + dev_err(ssbi->dev, "%s: timeout (status %x set_mask %x clr_mask %x)\n", + __func__, ssbi_readl(ssbi, SSBI2_STATUS), set_mask, clr_mask); + return -ETIMEDOUT; +} + +static int +msm_ssbi_read_bytes(struct msm_ssbi *ssbi, u16 addr, u8 *buf, int len) +{ + u32 cmd = SSBI_CMD_RDWRN | ((addr & 0xff) << 16); + int ret = 0; + + if (ssbi->controller_type == MSM_SBI_CTRL_SSBI2) { + u32 mode2 = ssbi_readl(ssbi, SSBI2_MODE2); + mode2 = SET_SSBI_MODE2_REG_ADDR_15_8(mode2, addr); + ssbi_writel(ssbi, mode2, SSBI2_MODE2); + } + + while (len) { + ret = ssbi_wait_mask(ssbi, SSBI_STATUS_READY, 0); + if (ret) + goto err; + + ssbi_writel(ssbi, cmd, SSBI2_CMD); + ret = ssbi_wait_mask(ssbi, SSBI_STATUS_RD_READY, 0); + if (ret) + goto err; + *buf++ = ssbi_readl(ssbi, SSBI2_RD) & 0xff; + len--; + } + +err: + return ret; +} + +static int +msm_ssbi_write_bytes(struct msm_ssbi *ssbi, u16 addr, u8 *buf, int len) +{ + int ret = 0; + + if (ssbi->controller_type == MSM_SBI_CTRL_SSBI2) { + u32 mode2 = ssbi_readl(ssbi, SSBI2_MODE2); + mode2 = SET_SSBI_MODE2_REG_ADDR_15_8(mode2, addr); + ssbi_writel(ssbi, mode2, SSBI2_MODE2); + } + + while (len) { + ret = ssbi_wait_mask(ssbi, SSBI_STATUS_READY, 0); + if (ret) + goto err; + + ssbi_writel(ssbi, ((addr & 0xff) << 16) | *buf, SSBI2_CMD); + ret = ssbi_wait_mask(ssbi, 0, SSBI_STATUS_MCHN_BUSY); + if (ret) + goto err; + buf++; + len--; + } + +err: + return ret; +} + +static inline int +msm_ssbi_pa_transfer(struct msm_ssbi *ssbi, u32 cmd, u8 *data) +{ + u32 timeout = SSBI_TIMEOUT_US; + u32 rd_status = 0; + + ssbi_writel(ssbi, cmd, SSBI_PA_CMD); + + while (timeout--) { + rd_status = ssbi_readl(ssbi, SSBI_PA_RD_STATUS); + + if (rd_status & SSBI_PA_RD_STATUS_TRANS_DENIED) { + dev_err(ssbi->dev, "%s: transaction denied (0x%x)\n", + __func__, rd_status); + return -EPERM; + } + + if (rd_status & SSBI_PA_RD_STATUS_TRANS_DONE) { + if (data) + *data = rd_status & 0xff; + return 0; + } + udelay(1); + } + + dev_err(ssbi->dev, "%s: timeout, status 0x%x\n", __func__, rd_status); + return -ETIMEDOUT; +} + +static int +msm_ssbi_pa_read_bytes(struct msm_ssbi *ssbi, u16 addr, u8 *buf, int len) +{ + u32 cmd; + int ret = 0; + + cmd = SSBI_PA_CMD_RDWRN | (addr & SSBI_PA_CMD_ADDR_MASK) << 8; + + while (len) { + ret = msm_ssbi_pa_transfer(ssbi, cmd, buf); + if (ret) + goto err; + buf++; + len--; + } + +err: + return ret; +} + +static int +msm_ssbi_pa_write_bytes(struct msm_ssbi *ssbi, u16 addr, u8 *buf, int len) +{ + u32 cmd; + int ret = 0; + + while (len) { + cmd = (addr & SSBI_PA_CMD_ADDR_MASK) << 8 | *buf; + ret = msm_ssbi_pa_transfer(ssbi, cmd, NULL); + if (ret) + goto err; + buf++; + len--; + } + +err: + return ret; +} + +int msm_ssbi_read(struct device *dev, u16 addr, u8 *buf, int len) +{ + struct msm_ssbi *ssbi = to_msm_ssbi(dev); + unsigned long flags; + int ret; + + if (ssbi->dev != dev) + return -ENXIO; + + spin_lock_irqsave(&ssbi->lock, flags); + ret = ssbi->read(ssbi, addr, buf, len); + spin_unlock_irqrestore(&ssbi->lock, flags); + + return ret; +} +EXPORT_SYMBOL(msm_ssbi_read); + +int msm_ssbi_write(struct device *dev, u16 addr, u8 *buf, int len) +{ + struct msm_ssbi *ssbi = to_msm_ssbi(dev); + unsigned long flags; + int ret; + + if (ssbi->dev != dev) + return -ENXIO; + + spin_lock_irqsave(&ssbi->lock, flags); + ret = ssbi->write(ssbi, addr, buf, len); + spin_unlock_irqrestore(&ssbi->lock, flags); + + return ret; +} +EXPORT_SYMBOL(msm_ssbi_write); + +static int msm_ssbi_add_slave(struct msm_ssbi *ssbi, + const struct msm_ssbi_slave_info *slave) +{ + struct platform_device *slave_pdev; + int ret; + + if (ssbi->slave) { + pr_err("slave already attached??\n"); + return -EBUSY; + } + + slave_pdev = platform_device_alloc(slave->name, -1); + if (!slave_pdev) { + pr_err("cannot allocate pdev for slave '%s'", slave->name); + ret = -ENOMEM; + goto err; + } + + slave_pdev->dev.parent = ssbi->dev; + slave_pdev->dev.platform_data = slave->platform_data; + + ret = platform_device_add(slave_pdev); + if (ret) { + pr_err("cannot add slave platform device for '%s'\n", + slave->name); + goto err; + } + + ssbi->slave = &slave_pdev->dev; + return 0; + +err: + if (slave_pdev) + platform_device_put(slave_pdev); + return ret; +} + +static int msm_ssbi_probe(struct platform_device *pdev) +{ + const struct msm_ssbi_platform_data *pdata = pdev->dev.platform_data; + struct resource *mem_res; + struct msm_ssbi *ssbi; + int ret = 0; + + if (!pdata) { + pr_err("missing platform data\n"); + return -EINVAL; + } + + pr_debug("%s\n", pdata->slave.name); + + ssbi = kzalloc(sizeof(struct msm_ssbi), GFP_KERNEL); + if (!ssbi) { + pr_err("can not allocate ssbi_data\n"); + return -ENOMEM; + } + + mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem_res) { + pr_err("missing mem resource\n"); + ret = -EINVAL; + goto err_get_mem_res; + } + + ssbi->base = ioremap(mem_res->start, resource_size(mem_res)); + if (!ssbi->base) { + pr_err("ioremap of 0x%p failed\n", (void *)mem_res->start); + ret = -EINVAL; + goto err_ioremap; + } + ssbi->dev = &pdev->dev; + platform_set_drvdata(pdev, ssbi); + + ssbi->controller_type = pdata->controller_type; + if (ssbi->controller_type == MSM_SBI_CTRL_PMIC_ARBITER) { + ssbi->read = msm_ssbi_pa_read_bytes; + ssbi->write = msm_ssbi_pa_write_bytes; + } else { + ssbi->read = msm_ssbi_read_bytes; + ssbi->write = msm_ssbi_write_bytes; + } + + spin_lock_init(&ssbi->lock); + + ret = msm_ssbi_add_slave(ssbi, &pdata->slave); + if (ret) + goto err_ssbi_add_slave; + + return 0; + +err_ssbi_add_slave: + platform_set_drvdata(pdev, NULL); + iounmap(ssbi->base); +err_ioremap: +err_get_mem_res: + kfree(ssbi); + return ret; +} + +static int msm_ssbi_remove(struct platform_device *pdev) +{ + struct msm_ssbi *ssbi = platform_get_drvdata(pdev); + + platform_set_drvdata(pdev, NULL); + iounmap(ssbi->base); + kfree(ssbi); + return 0; +} + +static struct platform_driver msm_ssbi_driver = { + .probe = msm_ssbi_probe, + .remove = __exit_p(msm_ssbi_remove), + .driver = { + .name = "msm_ssbi", + .owner = THIS_MODULE, + }, +}; + +static int __init msm_ssbi_init(void) +{ + return platform_driver_register(&msm_ssbi_driver); +} +postcore_initcall(msm_ssbi_init); + +static void __exit msm_ssbi_exit(void) +{ + platform_driver_unregister(&msm_ssbi_driver); +} +module_exit(msm_ssbi_exit) + +MODULE_LICENSE("GPL v2"); +MODULE_VERSION("1.0"); +MODULE_ALIAS("platform:msm_ssbi"); +MODULE_AUTHOR("Dima Zavin <dima@android.com>"); |