--- /dev/null
+/*
+ * 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 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");
Code Review / kvmfornfv.git / blobdiff