| /* |
| * Platform CAN bus driver for Bosch C_CAN controller |
| * |
| * Copyright (C) 2010 ST Microelectronics |
| * Bhupesh Sharma <bhupesh.sharma@st.com> |
| * |
| * Borrowed heavily from the C_CAN driver originally written by: |
| * Copyright (C) 2007 |
| * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de> |
| * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch> |
| * |
| * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B. |
| * Bosch C_CAN user manual can be obtained from: |
| * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/ |
| * users_manual_c_can.pdf |
| * |
| * This file is licensed under the terms of the GNU General Public |
| * License version 2. This program is licensed "as is" without any |
| * warranty of any kind, whether express or implied. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/interrupt.h> |
| #include <linux/delay.h> |
| #include <linux/netdevice.h> |
| #include <linux/if_arp.h> |
| #include <linux/if_ether.h> |
| #include <linux/list.h> |
| #include <linux/io.h> |
| #include <linux/platform_device.h> |
| #include <linux/clk.h> |
| #include <linux/of.h> |
| #include <linux/of_device.h> |
| |
| #include <linux/can/dev.h> |
| |
| #include "c_can.h" |
| |
| #define CAN_RAMINIT_START_MASK(i) (0x001 << (i)) |
| #define CAN_RAMINIT_DONE_MASK(i) (0x100 << (i)) |
| #define CAN_RAMINIT_ALL_MASK(i) (0x101 << (i)) |
| #define DCAN_RAM_INIT_BIT (1 << 3) |
| static DEFINE_SPINLOCK(raminit_lock); |
| /* |
| * 16-bit c_can registers can be arranged differently in the memory |
| * architecture of different implementations. For example: 16-bit |
| * registers can be aligned to a 16-bit boundary or 32-bit boundary etc. |
| * Handle the same by providing a common read/write interface. |
| */ |
| static u16 c_can_plat_read_reg_aligned_to_16bit(const struct c_can_priv *priv, |
| enum reg index) |
| { |
| return readw(priv->base + priv->regs[index]); |
| } |
| |
| static void c_can_plat_write_reg_aligned_to_16bit(const struct c_can_priv *priv, |
| enum reg index, u16 val) |
| { |
| writew(val, priv->base + priv->regs[index]); |
| } |
| |
| static u16 c_can_plat_read_reg_aligned_to_32bit(const struct c_can_priv *priv, |
| enum reg index) |
| { |
| return readw(priv->base + 2 * priv->regs[index]); |
| } |
| |
| static void c_can_plat_write_reg_aligned_to_32bit(const struct c_can_priv *priv, |
| enum reg index, u16 val) |
| { |
| writew(val, priv->base + 2 * priv->regs[index]); |
| } |
| |
| static void c_can_hw_raminit_wait_ti(const struct c_can_priv *priv, u32 mask, |
| u32 val) |
| { |
| /* We look only at the bits of our instance. */ |
| val &= mask; |
| while ((readl(priv->raminit_ctrlreg) & mask) != val) |
| udelay(1); |
| } |
| |
| static void c_can_hw_raminit_ti(const struct c_can_priv *priv, bool enable) |
| { |
| u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance); |
| u32 ctrl; |
| |
| spin_lock(&raminit_lock); |
| |
| ctrl = readl(priv->raminit_ctrlreg); |
| /* We clear the done and start bit first. The start bit is |
| * looking at the 0 -> transition, but is not self clearing; |
| * And we clear the init done bit as well. |
| */ |
| ctrl &= ~CAN_RAMINIT_START_MASK(priv->instance); |
| ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance); |
| writel(ctrl, priv->raminit_ctrlreg); |
| ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance); |
| c_can_hw_raminit_wait_ti(priv, ctrl, mask); |
| |
| if (enable) { |
| /* Set start bit and wait for the done bit. */ |
| ctrl |= CAN_RAMINIT_START_MASK(priv->instance); |
| writel(ctrl, priv->raminit_ctrlreg); |
| ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance); |
| c_can_hw_raminit_wait_ti(priv, ctrl, mask); |
| } |
| spin_unlock(&raminit_lock); |
| } |
| |
| static u32 c_can_plat_read_reg32(const struct c_can_priv *priv, enum reg index) |
| { |
| u32 val; |
| |
| val = priv->read_reg(priv, index); |
| val |= ((u32) priv->read_reg(priv, index + 1)) << 16; |
| |
| return val; |
| } |
| |
| static void c_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index, |
| u32 val) |
| { |
| priv->write_reg(priv, index + 1, val >> 16); |
| priv->write_reg(priv, index, val); |
| } |
| |
| static u32 d_can_plat_read_reg32(const struct c_can_priv *priv, enum reg index) |
| { |
| return readl(priv->base + priv->regs[index]); |
| } |
| |
| static void d_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index, |
| u32 val) |
| { |
| writel(val, priv->base + priv->regs[index]); |
| } |
| |
| static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask) |
| { |
| while (priv->read_reg32(priv, C_CAN_FUNCTION_REG) & mask) |
| udelay(1); |
| } |
| |
| static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable) |
| { |
| u32 ctrl; |
| |
| ctrl = priv->read_reg32(priv, C_CAN_FUNCTION_REG); |
| ctrl &= ~DCAN_RAM_INIT_BIT; |
| priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl); |
| c_can_hw_raminit_wait(priv, ctrl); |
| |
| if (enable) { |
| ctrl |= DCAN_RAM_INIT_BIT; |
| priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl); |
| c_can_hw_raminit_wait(priv, ctrl); |
| } |
| } |
| |
| static struct platform_device_id c_can_id_table[] = { |
| [BOSCH_C_CAN_PLATFORM] = { |
| .name = KBUILD_MODNAME, |
| .driver_data = BOSCH_C_CAN, |
| }, |
| [BOSCH_C_CAN] = { |
| .name = "c_can", |
| .driver_data = BOSCH_C_CAN, |
| }, |
| [BOSCH_D_CAN] = { |
| .name = "d_can", |
| .driver_data = BOSCH_D_CAN, |
| }, { |
| } |
| }; |
| MODULE_DEVICE_TABLE(platform, c_can_id_table); |
| |
| static const struct of_device_id c_can_of_table[] = { |
| { .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] }, |
| { .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] }, |
| { /* sentinel */ }, |
| }; |
| MODULE_DEVICE_TABLE(of, c_can_of_table); |
| |
| static int c_can_plat_probe(struct platform_device *pdev) |
| { |
| int ret; |
| void __iomem *addr; |
| struct net_device *dev; |
| struct c_can_priv *priv; |
| const struct of_device_id *match; |
| const struct platform_device_id *id; |
| struct resource *mem, *res; |
| int irq; |
| struct clk *clk; |
| |
| if (pdev->dev.of_node) { |
| match = of_match_device(c_can_of_table, &pdev->dev); |
| if (!match) { |
| dev_err(&pdev->dev, "Failed to find matching dt id\n"); |
| ret = -EINVAL; |
| goto exit; |
| } |
| id = match->data; |
| } else { |
| id = platform_get_device_id(pdev); |
| } |
| |
| /* get the appropriate clk */ |
| clk = devm_clk_get(&pdev->dev, NULL); |
| if (IS_ERR(clk)) { |
| ret = PTR_ERR(clk); |
| goto exit; |
| } |
| |
| /* get the platform data */ |
| irq = platform_get_irq(pdev, 0); |
| if (irq <= 0) { |
| ret = -ENODEV; |
| goto exit; |
| } |
| |
| mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| addr = devm_ioremap_resource(&pdev->dev, mem); |
| if (IS_ERR(addr)) { |
| ret = PTR_ERR(addr); |
| goto exit; |
| } |
| |
| /* allocate the c_can device */ |
| dev = alloc_c_can_dev(); |
| if (!dev) { |
| ret = -ENOMEM; |
| goto exit; |
| } |
| |
| priv = netdev_priv(dev); |
| switch (id->driver_data) { |
| case BOSCH_C_CAN: |
| priv->regs = reg_map_c_can; |
| switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) { |
| case IORESOURCE_MEM_32BIT: |
| priv->read_reg = c_can_plat_read_reg_aligned_to_32bit; |
| priv->write_reg = c_can_plat_write_reg_aligned_to_32bit; |
| priv->read_reg32 = c_can_plat_read_reg32; |
| priv->write_reg32 = c_can_plat_write_reg32; |
| break; |
| case IORESOURCE_MEM_16BIT: |
| default: |
| priv->read_reg = c_can_plat_read_reg_aligned_to_16bit; |
| priv->write_reg = c_can_plat_write_reg_aligned_to_16bit; |
| priv->read_reg32 = c_can_plat_read_reg32; |
| priv->write_reg32 = c_can_plat_write_reg32; |
| break; |
| } |
| break; |
| case BOSCH_D_CAN: |
| priv->regs = reg_map_d_can; |
| priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES; |
| priv->read_reg = c_can_plat_read_reg_aligned_to_16bit; |
| priv->write_reg = c_can_plat_write_reg_aligned_to_16bit; |
| priv->read_reg32 = d_can_plat_read_reg32; |
| priv->write_reg32 = d_can_plat_write_reg32; |
| |
| if (pdev->dev.of_node) |
| priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can"); |
| else |
| priv->instance = pdev->id; |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 1); |
| /* Not all D_CAN modules have a separate register for the D_CAN |
| * RAM initialization. Use default RAM init bit in D_CAN module |
| * if not specified in DT. |
| */ |
| if (!res) { |
| priv->raminit = c_can_hw_raminit; |
| break; |
| } |
| |
| priv->raminit_ctrlreg = devm_ioremap(&pdev->dev, res->start, |
| resource_size(res)); |
| if (IS_ERR(priv->raminit_ctrlreg) || priv->instance < 0) |
| dev_info(&pdev->dev, "control memory is not used for raminit\n"); |
| else |
| priv->raminit = c_can_hw_raminit_ti; |
| break; |
| default: |
| ret = -EINVAL; |
| goto exit_free_device; |
| } |
| |
| dev->irq = irq; |
| priv->base = addr; |
| priv->device = &pdev->dev; |
| priv->can.clock.freq = clk_get_rate(clk); |
| priv->priv = clk; |
| priv->type = id->driver_data; |
| |
| platform_set_drvdata(pdev, dev); |
| SET_NETDEV_DEV(dev, &pdev->dev); |
| |
| ret = register_c_can_dev(dev); |
| if (ret) { |
| dev_err(&pdev->dev, "registering %s failed (err=%d)\n", |
| KBUILD_MODNAME, ret); |
| goto exit_free_device; |
| } |
| |
| dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n", |
| KBUILD_MODNAME, priv->base, dev->irq); |
| return 0; |
| |
| exit_free_device: |
| free_c_can_dev(dev); |
| exit: |
| dev_err(&pdev->dev, "probe failed\n"); |
| |
| return ret; |
| } |
| |
| static int c_can_plat_remove(struct platform_device *pdev) |
| { |
| struct net_device *dev = platform_get_drvdata(pdev); |
| |
| unregister_c_can_dev(dev); |
| |
| free_c_can_dev(dev); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM |
| static int c_can_suspend(struct platform_device *pdev, pm_message_t state) |
| { |
| int ret; |
| struct net_device *ndev = platform_get_drvdata(pdev); |
| struct c_can_priv *priv = netdev_priv(ndev); |
| |
| if (priv->type != BOSCH_D_CAN) { |
| dev_warn(&pdev->dev, "Not supported\n"); |
| return 0; |
| } |
| |
| if (netif_running(ndev)) { |
| netif_stop_queue(ndev); |
| netif_device_detach(ndev); |
| } |
| |
| ret = c_can_power_down(ndev); |
| if (ret) { |
| netdev_err(ndev, "failed to enter power down mode\n"); |
| return ret; |
| } |
| |
| priv->can.state = CAN_STATE_SLEEPING; |
| |
| return 0; |
| } |
| |
| static int c_can_resume(struct platform_device *pdev) |
| { |
| int ret; |
| struct net_device *ndev = platform_get_drvdata(pdev); |
| struct c_can_priv *priv = netdev_priv(ndev); |
| |
| if (priv->type != BOSCH_D_CAN) { |
| dev_warn(&pdev->dev, "Not supported\n"); |
| return 0; |
| } |
| |
| ret = c_can_power_up(ndev); |
| if (ret) { |
| netdev_err(ndev, "Still in power down mode\n"); |
| return ret; |
| } |
| |
| priv->can.state = CAN_STATE_ERROR_ACTIVE; |
| |
| if (netif_running(ndev)) { |
| netif_device_attach(ndev); |
| netif_start_queue(ndev); |
| } |
| |
| return 0; |
| } |
| #else |
| #define c_can_suspend NULL |
| #define c_can_resume NULL |
| #endif |
| |
| static struct platform_driver c_can_plat_driver = { |
| .driver = { |
| .name = KBUILD_MODNAME, |
| .owner = THIS_MODULE, |
| .of_match_table = c_can_of_table, |
| }, |
| .probe = c_can_plat_probe, |
| .remove = c_can_plat_remove, |
| .suspend = c_can_suspend, |
| .resume = c_can_resume, |
| .id_table = c_can_id_table, |
| }; |
| |
| module_platform_driver(c_can_plat_driver); |
| |
| MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller"); |