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path: root/drivers/w1/masters/mxc_w1.c
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Diffstat (limited to 'drivers/w1/masters/mxc_w1.c')
-rw-r--r--drivers/w1/masters/mxc_w1.c146
1 files changed, 58 insertions, 88 deletions
diff --git a/drivers/w1/masters/mxc_w1.c b/drivers/w1/masters/mxc_w1.c
index a3b6a74c67a..a5df5e89d45 100644
--- a/drivers/w1/masters/mxc_w1.c
+++ b/drivers/w1/masters/mxc_w1.c
@@ -10,24 +10,16 @@
* 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
- *
*/
-#include <linux/module.h>
-#include <linux/interrupt.h>
-#include <linux/platform_device.h>
#include <linux/clk.h>
-#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
#include "../w1.h"
#include "../w1_int.h"
-#include "../w1_log.h"
/* According to the mx27 Datasheet the reset procedure should take up to about
* 1350us. We set the timeout to 500*100us = 50ms for sure */
@@ -36,17 +28,16 @@
/*
* MXC W1 Register offsets
*/
-#define MXC_W1_CONTROL 0x00
-#define MXC_W1_TIME_DIVIDER 0x02
-#define MXC_W1_RESET 0x04
-#define MXC_W1_COMMAND 0x06
-#define MXC_W1_TXRX 0x08
-#define MXC_W1_INTERRUPT 0x0A
-#define MXC_W1_INTERRUPT_EN 0x0C
+#define MXC_W1_CONTROL 0x00
+# define MXC_W1_CONTROL_RDST BIT(3)
+# define MXC_W1_CONTROL_WR(x) BIT(5 - (x))
+# define MXC_W1_CONTROL_PST BIT(6)
+# define MXC_W1_CONTROL_RPP BIT(7)
+#define MXC_W1_TIME_DIVIDER 0x02
+#define MXC_W1_RESET 0x04
struct mxc_w1_device {
void __iomem *regs;
- unsigned int clkdiv;
struct clk *clk;
struct w1_bus_master bus_master;
};
@@ -62,12 +53,12 @@ static u8 mxc_w1_ds2_reset_bus(void *data)
unsigned int timeout_cnt = 0;
struct mxc_w1_device *dev = data;
- __raw_writeb(0x80, (dev->regs + MXC_W1_CONTROL));
+ writeb(MXC_W1_CONTROL_RPP, (dev->regs + MXC_W1_CONTROL));
while (1) {
- reg_val = __raw_readb(dev->regs + MXC_W1_CONTROL);
+ reg_val = readb(dev->regs + MXC_W1_CONTROL);
- if (((reg_val >> 7) & 0x1) == 0 ||
+ if (!(reg_val & MXC_W1_CONTROL_RPP) ||
timeout_cnt > MXC_W1_RESET_TIMEOUT)
break;
else
@@ -75,7 +66,7 @@ static u8 mxc_w1_ds2_reset_bus(void *data)
udelay(100);
}
- return (reg_val >> 7) & 0x1;
+ return !(reg_val & MXC_W1_CONTROL_PST);
}
/*
@@ -91,121 +82,100 @@ static u8 mxc_w1_ds2_touch_bit(void *data, u8 bit)
* datasheet.
*/
- __raw_writeb((1 << (5 - bit)), ctrl_addr);
+ writeb(MXC_W1_CONTROL_WR(bit), ctrl_addr);
while (timeout_cnt--) {
- if (!((__raw_readb(ctrl_addr) >> (5 - bit)) & 0x1))
+ if (!(readb(ctrl_addr) & MXC_W1_CONTROL_WR(bit)))
break;
udelay(1);
}
- return ((__raw_readb(ctrl_addr)) >> 3) & 0x1;
+ return !!(readb(ctrl_addr) & MXC_W1_CONTROL_RDST);
}
-static int __devinit mxc_w1_probe(struct platform_device *pdev)
+static int mxc_w1_probe(struct platform_device *pdev)
{
struct mxc_w1_device *mdev;
+ unsigned long clkrate;
struct resource *res;
- int err = 0;
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res)
- return -ENODEV;
+ unsigned int clkdiv;
+ int err;
- mdev = kzalloc(sizeof(struct mxc_w1_device), GFP_KERNEL);
+ mdev = devm_kzalloc(&pdev->dev, sizeof(struct mxc_w1_device),
+ GFP_KERNEL);
if (!mdev)
return -ENOMEM;
- mdev->clk = clk_get(&pdev->dev, "owire");
- if (!mdev->clk) {
- err = -ENODEV;
- goto failed_clk;
- }
+ mdev->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(mdev->clk))
+ return PTR_ERR(mdev->clk);
- mdev->clkdiv = (clk_get_rate(mdev->clk) / 1000000) - 1;
+ clkrate = clk_get_rate(mdev->clk);
+ if (clkrate < 10000000)
+ dev_warn(&pdev->dev,
+ "Low clock frequency causes improper function\n");
- res = request_mem_region(res->start, resource_size(res),
- "mxc_w1");
- if (!res) {
- err = -EBUSY;
- goto failed_req;
- }
+ clkdiv = DIV_ROUND_CLOSEST(clkrate, 1000000);
+ clkrate /= clkdiv;
+ if ((clkrate < 980000) || (clkrate > 1020000))
+ dev_warn(&pdev->dev,
+ "Incorrect time base frequency %lu Hz\n", clkrate);
- mdev->regs = ioremap(res->start, resource_size(res));
- if (!mdev->regs) {
- printk(KERN_ERR "Cannot map frame buffer registers\n");
- goto failed_ioremap;
- }
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mdev->regs = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mdev->regs))
+ return PTR_ERR(mdev->regs);
- clk_enable(mdev->clk);
- __raw_writeb(mdev->clkdiv, mdev->regs + MXC_W1_TIME_DIVIDER);
+ err = clk_prepare_enable(mdev->clk);
+ if (err)
+ return err;
+
+ writeb(clkdiv - 1, mdev->regs + MXC_W1_TIME_DIVIDER);
mdev->bus_master.data = mdev;
mdev->bus_master.reset_bus = mxc_w1_ds2_reset_bus;
mdev->bus_master.touch_bit = mxc_w1_ds2_touch_bit;
- err = w1_add_master_device(&mdev->bus_master);
+ platform_set_drvdata(pdev, mdev);
+ err = w1_add_master_device(&mdev->bus_master);
if (err)
- goto failed_add;
+ clk_disable_unprepare(mdev->clk);
- platform_set_drvdata(pdev, mdev);
- return 0;
-
-failed_add:
- iounmap(mdev->regs);
-failed_ioremap:
- release_mem_region(res->start, resource_size(res));
-failed_req:
- clk_put(mdev->clk);
-failed_clk:
- kfree(mdev);
return err;
}
/*
* disassociate the w1 device from the driver
*/
-static int __devexit mxc_w1_remove(struct platform_device *pdev)
+static int mxc_w1_remove(struct platform_device *pdev)
{
struct mxc_w1_device *mdev = platform_get_drvdata(pdev);
- struct resource *res;
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
w1_remove_master_device(&mdev->bus_master);
- iounmap(mdev->regs);
- release_mem_region(res->start, resource_size(res));
- clk_disable(mdev->clk);
- clk_put(mdev->clk);
-
- platform_set_drvdata(pdev, NULL);
+ clk_disable_unprepare(mdev->clk);
return 0;
}
+static struct of_device_id mxc_w1_dt_ids[] = {
+ { .compatible = "fsl,imx21-owire" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxc_w1_dt_ids);
+
static struct platform_driver mxc_w1_driver = {
.driver = {
- .name = "mxc_w1",
+ .name = "mxc_w1",
+ .owner = THIS_MODULE,
+ .of_match_table = mxc_w1_dt_ids,
},
.probe = mxc_w1_probe,
.remove = mxc_w1_remove,
};
-
-static int __init mxc_w1_init(void)
-{
- return platform_driver_register(&mxc_w1_driver);
-}
-
-static void mxc_w1_exit(void)
-{
- platform_driver_unregister(&mxc_w1_driver);
-}
-
-module_init(mxc_w1_init);
-module_exit(mxc_w1_exit);
+module_platform_driver(mxc_w1_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Freescale Semiconductors Inc");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 01:55:01 +0000