| /* |
| * 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/mfd/syscon.h> |
| #include <linux/regmap.h> |
| |
| #include <linux/can/dev.h> |
| |
| #include "c_can.h" |
| |
| #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_syscon(const struct c_can_priv *priv, |
| u32 mask, u32 val) |
| { |
| const struct c_can_raminit *raminit = &priv->raminit_sys; |
| int timeout = 0; |
| u32 ctrl = 0; |
| |
| /* We look only at the bits of our instance. */ |
| val &= mask; |
| do { |
| udelay(1); |
| timeout++; |
| |
| regmap_read(raminit->syscon, raminit->reg, &ctrl); |
| if (timeout == 1000) { |
| dev_err(&priv->dev->dev, "%s: time out\n", __func__); |
| break; |
| } |
| } while ((ctrl & mask) != val); |
| } |
| |
| static void c_can_hw_raminit_syscon(const struct c_can_priv *priv, bool enable) |
| { |
| const struct c_can_raminit *raminit = &priv->raminit_sys; |
| u32 ctrl = 0; |
| u32 mask; |
| |
| spin_lock(&raminit_lock); |
| |
| mask = 1 << raminit->bits.start | 1 << raminit->bits.done; |
| regmap_read(raminit->syscon, raminit->reg, &ctrl); |
| |
| /* We clear the start bit first. The start bit is |
| * looking at the 0 -> transition, but is not self clearing; |
| * NOTE: DONE must be written with 1 to clear it. |
| * We can't clear the DONE bit here using regmap_update_bits() |
| * as it will bypass the write if initial condition is START:0 DONE:1 |
| * e.g. on DRA7 which needs START pulse. |
| */ |
| ctrl &= ~mask; /* START = 0, DONE = 0 */ |
| regmap_update_bits(raminit->syscon, raminit->reg, mask, ctrl); |
| |
| /* check if START bit is 0. Ignore DONE bit for now |
| * as it can be either 0 or 1. |
| */ |
| c_can_hw_raminit_wait_syscon(priv, 1 << raminit->bits.start, ctrl); |
| |
| if (enable) { |
| /* Clear DONE bit & set START bit. */ |
| ctrl |= 1 << raminit->bits.start; |
| /* DONE must be written with 1 to clear it */ |
| ctrl |= 1 << raminit->bits.done; |
| regmap_update_bits(raminit->syscon, raminit->reg, mask, ctrl); |
| /* prevent further clearing of DONE bit */ |
| ctrl &= ~(1 << raminit->bits.done); |
| /* clear START bit if start pulse is needed */ |
| if (raminit->needs_pulse) { |
| ctrl &= ~(1 << raminit->bits.start); |
| regmap_update_bits(raminit->syscon, raminit->reg, |
| mask, ctrl); |
| } |
| |
| ctrl |= 1 << raminit->bits.done; |
| c_can_hw_raminit_wait_syscon(priv, mask, ctrl); |
| } |
| 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 const struct c_can_driver_data c_can_drvdata = { |
| .id = BOSCH_C_CAN, |
| }; |
| |
| static const struct c_can_driver_data d_can_drvdata = { |
| .id = BOSCH_D_CAN, |
| }; |
| |
| static const struct raminit_bits dra7_raminit_bits[] = { |
| [0] = { .start = 3, .done = 1, }, |
| [1] = { .start = 5, .done = 2, }, |
| }; |
| |
| static const struct c_can_driver_data dra7_dcan_drvdata = { |
| .id = BOSCH_D_CAN, |
| .raminit_num = ARRAY_SIZE(dra7_raminit_bits), |
| .raminit_bits = dra7_raminit_bits, |
| .raminit_pulse = true, |
| }; |
| |
| static const struct raminit_bits am3352_raminit_bits[] = { |
| [0] = { .start = 0, .done = 8, }, |
| [1] = { .start = 1, .done = 9, }, |
| }; |
| |
| static const struct c_can_driver_data am3352_dcan_drvdata = { |
| .id = BOSCH_D_CAN, |
| .raminit_num = ARRAY_SIZE(am3352_raminit_bits), |
| .raminit_bits = am3352_raminit_bits, |
| }; |
| |
| static const struct platform_device_id c_can_id_table[] = { |
| { |
| .name = KBUILD_MODNAME, |
| .driver_data = (kernel_ulong_t)&c_can_drvdata, |
| }, |
| { |
| .name = "c_can", |
| .driver_data = (kernel_ulong_t)&c_can_drvdata, |
| }, |
| { |
| .name = "d_can", |
| .driver_data = (kernel_ulong_t)&d_can_drvdata, |
| }, |
| { /* sentinel */ }, |
| }; |
| 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_drvdata }, |
| { .compatible = "bosch,d_can", .data = &d_can_drvdata }, |
| { .compatible = "ti,dra7-d_can", .data = &dra7_dcan_drvdata }, |
| { .compatible = "ti,am3352-d_can", .data = &am3352_dcan_drvdata }, |
| { .compatible = "ti,am4372-d_can", .data = &am3352_dcan_drvdata }, |
| { /* 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; |
| struct resource *mem; |
| int irq; |
| struct clk *clk; |
| const struct c_can_driver_data *drvdata; |
| struct device_node *np = pdev->dev.of_node; |
| |
| match = of_match_device(c_can_of_table, &pdev->dev); |
| if (match) { |
| drvdata = match->data; |
| } else if (pdev->id_entry->driver_data) { |
| drvdata = (struct c_can_driver_data *) |
| platform_get_device_id(pdev)->driver_data; |
| } else { |
| return -ENODEV; |
| } |
| |
| /* 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 (drvdata->id) { |
| 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; |
| |
| /* Check if we need custom RAMINIT via syscon. Mostly for TI |
| * platforms. Only supported with DT boot. |
| */ |
| if (np && of_property_read_bool(np, "syscon-raminit")) { |
| u32 id; |
| struct c_can_raminit *raminit = &priv->raminit_sys; |
| |
| ret = -EINVAL; |
| raminit->syscon = syscon_regmap_lookup_by_phandle(np, |
| "syscon-raminit"); |
| if (IS_ERR(raminit->syscon)) { |
| /* can fail with -EPROBE_DEFER */ |
| ret = PTR_ERR(raminit->syscon); |
| free_c_can_dev(dev); |
| return ret; |
| } |
| |
| if (of_property_read_u32_index(np, "syscon-raminit", 1, |
| &raminit->reg)) { |
| dev_err(&pdev->dev, |
| "couldn't get the RAMINIT reg. offset!\n"); |
| goto exit_free_device; |
| } |
| |
| if (of_property_read_u32_index(np, "syscon-raminit", 2, |
| &id)) { |
| dev_err(&pdev->dev, |
| "couldn't get the CAN instance ID\n"); |
| goto exit_free_device; |
| } |
| |
| if (id >= drvdata->raminit_num) { |
| dev_err(&pdev->dev, |
| "Invalid CAN instance ID\n"); |
| goto exit_free_device; |
| } |
| |
| raminit->bits = drvdata->raminit_bits[id]; |
| raminit->needs_pulse = drvdata->raminit_pulse; |
| |
| priv->raminit = c_can_hw_raminit_syscon; |
| } else { |
| priv->raminit = c_can_hw_raminit; |
| } |
| 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 = drvdata->id; |
| |
| 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, |
| .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"); |